Provided by: python-mpi4py-doc_4.0.3-3ubuntu1_all 
NAME
mpi4py - MPI for Python
Author Lisandro Dalcin
Contact
dalcinl@gmail.com
Date March 15, 2025
Abstract
MPI for Python provides Python bindings for the Message Passing Interface (MPI) standard, allowing Python
applications to exploit multiple processors on workstations, clusters and supercomputers.
This package builds on the MPI specification and provides an object oriented interface resembling the
MPI-2 C++ bindings. It supports point-to-point (sends, receives) and collective (broadcasts, scatters,
gathers) communication of any picklable Python object, as well as efficient communication of Python
objects exposing the Python buffer interface (e.g. NumPy arrays and builtin bytes/array/memoryview
objects).
INTRODUCTION
Over the last years, high performance computing has become an affordable resource to many more
researchers in the scientific community than ever before. The conjunction of quality open source software
and commodity hardware strongly influenced the now widespread popularity of Beowulf class clusters and
cluster of workstations.
Among many parallel computational models, message-passing has proven to be an effective one. This
paradigm is specially suited for (but not limited to) distributed memory architectures and is used in
today’s most demanding scientific and engineering application related to modeling, simulation, design,
and signal processing. However, portable message-passing parallel programming used to be a nightmare in
the past because of the many incompatible options developers were faced to. Fortunately, this situation
definitely changed after the MPI Forum released its standard specification.
High performance computing is traditionally associated with software development using compiled
languages. However, in typical applications programs, only a small part of the code is time-critical
enough to require the efficiency of compiled languages. The rest of the code is generally related to
memory management, error handling, input/output, and user interaction, and those are usually the most
error prone and time-consuming lines of code to write and debug in the whole development process.
Interpreted high-level languages can be really advantageous for this kind of tasks.
For implementing general-purpose numerical computations, MATLAB [1] is the dominant interpreted
programming language. In the open source side, Octave and Scilab are well known, freely distributed
software packages providing compatibility with the MATLAB language. In this work, we present MPI for
Python, a new package enabling applications to exploit multiple processors using standard MPI “look and
feel” in Python scripts.
[1] MATLAB is a registered trademark of The MathWorks, Inc.
What is MPI?
MPI, [mpi-using] [mpi-ref] the Message Passing Interface, is a standardized and portable message-passing
system designed to function on a wide variety of parallel computers. The standard defines the syntax and
semantics of library routines and allows users to write portable programs in the main scientific
programming languages (Fortran, C, or C++).
Since its release, the MPI specification [mpi-std1] [mpi-std2] has become the leading standard for
message-passing libraries for parallel computers. Implementations are available from vendors of
high-performance computers and from well known open source projects like MPICH [mpi-mpich] and Open MPI
[mpi-openmpi].
What is Python?
Python is a modern, easy to learn, powerful programming language. It has efficient high-level data
structures and a simple but effective approach to object-oriented programming with dynamic typing and
dynamic binding. It supports modules and packages, which encourages program modularity and code reuse.
Python’s elegant syntax, together with its interpreted nature, make it an ideal language for scripting
and rapid application development in many areas on most platforms.
The Python interpreter and the extensive standard library are available in source or binary form without
charge for all major platforms, and can be freely distributed. It is easily extended with new functions
and data types implemented in C or C++. Python is also suitable as an extension language for customizable
applications.
Python is an ideal candidate for writing the higher-level parts of large-scale scientific applications
[Hinsen97] and driving simulations in parallel architectures [Beazley97] like clusters of PC’s or SMP’s.
Python codes are quickly developed, easily maintained, and can achieve a high degree of integration with
other libraries written in compiled languages.
Related Projects
As this work started and evolved, some ideas were borrowed from well known MPI and Python related open
source projects from the Internet.
• OOMPI
• It has no relation with Python, but is an excellent object oriented approach to MPI.
• It is a C++ class library specification layered on top of the C bindings that encapsulates MPI into a
functional class hierarchy.
• It provides a flexible and intuitive interface by adding some abstractions, like Ports and Messages,
which enrich and simplify the syntax.
• Pypar
• Its interface is rather minimal. There is no support for communicators or process topologies.
• It does not require the Python interpreter to be modified or recompiled, but does not permit
interactive parallel runs.
• General (picklable) Python objects of any type can be communicated. There is good support for numeric
arrays, practically full MPI bandwidth can be achieved.
• pyMPI
• It rebuilds the Python interpreter providing a built-in module for message passing. It does permit
interactive parallel runs, which are useful for learning and debugging.
• It provides an interface suitable for basic parallel programming. There is not full support for
defining new communicators or process topologies.
• General (picklable) Python objects can be messaged between processors. There is native support for
numeric arrays.
• Scientific Python
• It provides a collection of Python modules that are useful for scientific computing.
• There is an interface to MPI and BSP (Bulk Synchronous Parallel programming).
• The interface is simple but incomplete and does not resemble the MPI specification. There is support
for numeric arrays.
Additionally, we would like to mention some available tools for scientific computing and software
development with Python.
• NumPy is a package that provides array manipulation and computational capabilities similar to those
found in IDL, MATLAB, or Octave. Using NumPy, it is possible to write many efficient numerical data
processing applications directly in Python without using any C, C++ or Fortran code.
• SciPy is an open source library of scientific tools for Python, gathering a variety of high level
science and engineering modules together as a single package. It includes modules for graphics and
plotting, optimization, integration, special functions, signal and image processing, genetic
algorithms, ODE solvers, and others.
• Cython is a language that makes writing C extensions for the Python language as easy as Python itself.
The Cython language is very close to the Python language, but Cython additionally supports calling C
functions and declaring C types on variables and class attributes. This allows the compiler to generate
very efficient C code from Cython code. This makes Cython the ideal language for wrapping for external
C libraries, and for fast C modules that speed up the execution of Python code.
• SWIG is a software development tool that connects programs written in C and C++ with a variety of
high-level programming languages like Perl, Tcl/Tk, Ruby and Python. Issuing header files to SWIG is
the simplest approach to interfacing C/C++ libraries from a Python module.
[mpi-std1]
MPI Forum. MPI: A Message Passing Interface Standard. International Journal of Supercomputer
Applications, volume 8, number 3-4, pages 159-416, 1994.
[mpi-std2]
MPI Forum. MPI: A Message Passing Interface Standard. High Performance Computing Applications,
volume 12, number 1-2, pages 1-299, 1998.
[mpi-using]
William Gropp, Ewing Lusk, and Anthony Skjellum. Using MPI: portable parallel programming with the
message-passing interface. MIT Press, 1994.
[mpi-ref]
Mark Snir, Steve Otto, Steven Huss-Lederman, David Walker, and Jack Dongarra. MPI - The Complete
Reference, volume 1, The MPI Core. MIT Press, 2nd. edition, 1998.
[mpi-mpich]
W. Gropp, E. Lusk, N. Doss, and A. Skjellum. A high-performance, portable implementation of the MPI
message passing interface standard. Parallel Computing, 22(6):789-828, September 1996.
[mpi-openmpi]
Edgar Gabriel, Graham E. Fagg, George Bosilca, Thara Angskun, Jack J. Dongarra, Jeffrey M. Squyres,
Vishal Sahay, Prabhanjan Kambadur, Brian Barrett, Andrew Lumsdaine, Ralph H. Castain, David J.
Daniel, Richard L. Graham, and Timothy S. Woodall. Open MPI: Goals, Concept, and Design of a Next
Generation MPI Implementation. In Proceedings, 11th European PVM/MPI Users’ Group Meeting, Budapest,
Hungary, September 2004.
[Hinsen97]
Konrad Hinsen. The Molecular Modelling Toolkit: a case study of a large scientific application in
Python. In Proceedings of the 6th International Python Conference, pages 29-35, San Jose, Ca.,
October 1997.
[Beazley97]
David M. Beazley and Peter S. Lomdahl. Feeding a large-scale physics application to Python. In
Proceedings of the 6th International Python Conference, pages 21-29, San Jose, Ca., October 1997.
OVERVIEW
MPI for Python provides an object oriented approach to message passing which grounds on the standard
MPI-2 C++ bindings. The interface was designed with focus in translating MPI syntax and semantics of
standard MPI-2 bindings for C++ to Python. Any user of the standard C/C++ MPI bindings should be able to
use this module without need of learning a new interface.
Communicating Python Objects and Array Data
The Python standard library supports different mechanisms for data persistence. Many of them rely on disk
storage, but pickling and marshaling can also work with memory buffers.
The pickle modules provide user-extensible facilities to serialize general Python objects using ASCII or
binary formats. The marshal module provides facilities to serialize built-in Python objects using a
binary format specific to Python, but independent of machine architecture issues.
MPI for Python can communicate any built-in or user-defined Python object taking advantage of the
features provided by the pickle module. These facilities will be routinely used to build binary
representations of objects to communicate (at sending processes), and restoring them back (at receiving
processes).
Although simple and general, the serialization approach (i.e., pickling and unpickling) previously
discussed imposes important overheads in memory as well as processor usage, especially in the scenario of
objects with large memory footprints being communicated. Pickling general Python objects, ranging from
primitive or container built-in types to user-defined classes, necessarily requires computer resources.
Processing is also needed for dispatching the appropriate serialization method (that depends on the type
of the object) and doing the actual packing. Additional memory is always needed, and if its total amount
is not known a priori, many reallocations can occur. Indeed, in the case of large numeric arrays, this
is certainly unacceptable and precludes communication of objects occupying half or more of the available
memory resources.
MPI for Python supports direct communication of any object exporting the single-segment buffer interface.
This interface is a standard Python mechanism provided by some types (e.g., strings and numeric arrays),
allowing access in the C side to a contiguous memory buffer (i.e., address and length) containing the
relevant data. This feature, in conjunction with the capability of constructing user-defined MPI
datatypes describing complicated memory layouts, enables the implementation of many algorithms involving
multidimensional numeric arrays (e.g., image processing, fast Fourier transforms, finite difference
schemes on structured Cartesian grids) directly in Python, with negligible overhead, and almost as fast
as compiled Fortran, C, or C++ codes.
Communicators
In MPI for Python, Comm is the base class of communicators. The Intracomm and Intercomm classes are
subclasses of the Comm class. The Comm.Is_inter method (and Comm.Is_intra, provided for convenience but
not part of the MPI specification) is defined for communicator objects and can be used to determine the
particular communicator class.
The two predefined intracommunicator instances are available: COMM_SELF and COMM_WORLD. From them, new
communicators can be created as needed.
The number of processes in a communicator and the calling process rank can be respectively obtained with
methods Comm.Get_size and Comm.Get_rank. The associated process group can be retrieved from a
communicator by calling the Comm.Get_group method, which returns an instance of the Group class. Set
operations with Group objects like like Group.Union, Group.Intersection and Group.Difference are fully
supported, as well as the creation of new communicators from these groups using Comm.Create and
Intracomm.Create_group.
New communicator instances can be obtained with the Comm.Clone, Comm.Dup and Comm.Split methods, as well
methods Intracomm.Create_intercomm and Intercomm.Merge.
Virtual topologies (Cartcomm, Graphcomm and Distgraphcomm classes, which are specializations of the
Intracomm class) are fully supported. New instances can be obtained from intracommunicator instances with
factory methods Intracomm.Create_cart and Intracomm.Create_graph.
Point-to-Point Communications
Point to point communication is a fundamental capability of message passing systems. This mechanism
enables the transmission of data between a pair of processes, one side sending, the other receiving.
MPI provides a set of send and receive functions allowing the communication of typed data with an
associated tag. The type information enables the conversion of data representation from one architecture
to another in the case of heterogeneous computing environments; additionally, it allows the
representation of non-contiguous data layouts and user-defined datatypes, thus avoiding the overhead of
(otherwise unavoidable) packing/unpacking operations. The tag information allows selectivity of messages
at the receiving end.
Blocking Communications
MPI provides basic send and receive functions that are blocking. These functions block the caller until
the data buffers involved in the communication can be safely reused by the application program.
In MPI for Python, the Comm.Send, Comm.Recv and Comm.Sendrecv methods of communicator objects provide
support for blocking point-to-point communications within Intracomm and Intercomm instances. These
methods can communicate memory buffers. The variants Comm.send, Comm.recv and Comm.sendrecv can
communicate general Python objects.
Nonblocking Communications
On many systems, performance can be significantly increased by overlapping communication and computation.
This is particularly true on systems where communication can be executed autonomously by an intelligent,
dedicated communication controller.
MPI provides nonblocking send and receive functions. They allow the possible overlap of communication and
computation. Non-blocking communication always come in two parts: posting functions, which begin the
requested operation; and test-for-completion functions, which allow to discover whether the requested
operation has completed.
In MPI for Python, the Comm.Isend and Comm.Irecv methods initiate send and receive operations,
respectively. These methods return a Request instance, uniquely identifying the started operation. Its
completion can be managed using the Request.Test, Request.Wait and Request.Cancel methods. The management
of Request objects and associated memory buffers involved in communication requires a careful, rather
low-level coordination. Users must ensure that objects exposing their memory buffers are not accessed at
the Python level while they are involved in nonblocking message-passing operations.
Persistent Communications
Often a communication with the same argument list is repeatedly executed within an inner loop. In such
cases, communication can be further optimized by using persistent communication, a particular case of
nonblocking communication allowing the reduction of the overhead between processes and communication
controllers. Furthermore , this kind of optimization can also alleviate the extra call overheads
associated to interpreted, dynamic languages like Python.
In MPI for Python, the Comm.Send_init and Comm.Recv_init methods create persistent requests for a send
and receive operation, respectively. These methods return an instance of the Prequest class, a subclass
of the Request class. The actual communication can be effectively started using the Prequest.Start
method, and its completion can be managed as previously described.
Collective Communications
Collective communications allow the transmittal of data between multiple processes of a group
simultaneously. The syntax and semantics of collective functions is consistent with point-to-point
communication. Collective functions communicate typed data, but messages are not paired with an
associated tag; selectivity of messages is implied in the calling order. Additionally, collective
functions come in blocking versions only.
The more commonly used collective communication operations are the following.
• Barrier synchronization across all group members.
• Global communication functions
• Broadcast data from one member to all members of a group.
• Gather data from all members to one member of a group.
• Scatter data from one member to all members of a group.
• Global reduction operations such as sum, maximum, minimum, etc.
In MPI for Python, the Comm.Bcast, Comm.Scatter, Comm.Gather, Comm.Allgather, Comm.Alltoall methods
provide support for collective communications of memory buffers. The lower-case variants Comm.bcast,
Comm.scatter, Comm.gather, Comm.allgather and Comm.alltoall can communicate general Python objects. The
vector variants (which can communicate different amounts of data to each process) Comm.Scatterv,
Comm.Gatherv, Comm.Allgatherv, Comm.Alltoallv and Comm.Alltoallw are also supported, they can only
communicate objects exposing memory buffers.
Global reduction operations on memory buffers are accessible through the Comm.Reduce,
Comm.Reduce_scatter, Comm.Allreduce, Intracomm.Scan and Intracomm.Exscan methods. The lower-case variants
Comm.reduce, Comm.allreduce, Intracomm.scan and Intracomm.exscan can communicate general Python objects;
however, the actual required reduction computations are performed sequentially at some process. All the
predefined (i.e., SUM, PROD, MAX, etc.) reduction operations can be applied.
Support for GPU-aware MPI
Several MPI implementations, including Open MPI and MVAPICH, support passing GPU pointers to MPI calls to
avoid explicit data movement between host and device. On the Python side, support for handling GPU arrays
have been implemented in many libraries related GPU computation such as CuPy, Numba, PyTorch, and ‐
PyArrow. To maximize interoperability across library boundaries, two kinds of zero-copy data exchange
protocols have been defined and agreed upon: DLPack and CUDA Array Interface (CAI).
MPI for Python provides an experimental support for GPU-aware MPI. This feature requires:
1. mpi4py is built against a GPU-aware MPI library.
2. The Python GPU arrays are compliant with either of the protocols.
See the Tutorial section for further information. We note that
• Whether or not a MPI call can work for GPU arrays depends on the underlying MPI implementation, not on
mpi4py.
• This support is currently experimental and subject to change in the future.
Dynamic Process Management
In the context of the MPI-1 specification, a parallel application is static; that is, no processes can be
added to or deleted from a running application after it has been started. Fortunately, this limitation
was addressed in MPI-2. The new specification added a process management model providing a basic
interface between an application and external resources and process managers.
This MPI-2 extension can be really useful, especially for sequential applications built on top of
parallel modules, or parallel applications with a client/server model. The MPI-2 process model provides a
mechanism to create new processes and establish communication between them and the existing MPI
application. It also provides mechanisms to establish communication between two existing MPI
applications, even when one did not start the other.
In MPI for Python, new independent process groups can be created by calling the Intracomm.Spawn method
within an intracommunicator. This call returns a new intercommunicator (i.e., an Intercomm instance) at
the parent process group. The child process group can retrieve the matching intercommunicator by calling
the Comm.Get_parent class method. At each side, the new intercommunicator can be used to perform point to
point and collective communications between the parent and child groups of processes.
Alternatively, disjoint groups of processes can establish communication using a client/server approach.
Any server application must first call the Open_port function to open a port and the Publish_name
function to publish a provided service, and next call the Intracomm.Accept method. Any client
applications can first find a published service by calling the Lookup_name function, which returns the
port where a server can be contacted; and next call the Intracomm.Connect method. Both Intracomm.Accept
and Intracomm.Connect methods return an Intercomm instance. When connection between client/server
processes is no longer needed, all of them must cooperatively call the Comm.Disconnect method.
Additionally, server applications should release resources by calling the Unpublish_name and Close_port
functions.
One-Sided Communications
One-sided communications (also called Remote Memory Access, RMA) supplements the traditional two-sided,
send/receive based MPI communication model with a one-sided, put/get based interface. One-sided
communication that can take advantage of the capabilities of highly specialized network hardware.
Additionally, this extension lowers latency and software overhead in applications written using a
shared-memory-like paradigm.
The MPI specification revolves around the use of objects called windows; they intuitively specify regions
of a process’s memory that have been made available for remote read and write operations. The published
memory blocks can be accessed through three functions for put (remote send), get (remote write), and
accumulate (remote update or reduction) data items. A much larger number of functions support different
synchronization styles; the semantics of these synchronization operations are fairly complex.
In MPI for Python, one-sided operations are available by using instances of the Win class. New window
objects are created by calling the Win.Create method at all processes within a communicator and
specifying a memory buffer . When a window instance is no longer needed, the Win.Free method should be
called.
The three one-sided MPI operations for remote write, read and reduction are available through calling the
methods Win.Put, Win.Get, and Win.Accumulate respectively within a Win instance. These methods need an
integer rank identifying the target process and an integer offset relative the base address of the remote
memory block being accessed.
The one-sided operations read, write, and reduction are implicitly nonblocking, and must be synchronized
by using two primary modes. Active target synchronization requires the origin process to call the
Win.Start and Win.Complete methods at the origin process, and target process cooperates by calling the
Win.Post and Win.Wait methods. There is also a collective variant provided by the Win.Fence method.
Passive target synchronization is more lenient, only the origin process calls the Win.Lock and Win.Unlock
methods. Locks are used to protect remote accesses to the locked remote window and to protect local
load/store accesses to a locked local window.
Parallel Input/Output
The POSIX standard provides a model of a widely portable file system. However, the optimization needed
for parallel input/output cannot be achieved with this generic interface. In order to ensure efficiency
and scalability, the underlying parallel input/output system must provide a high-level interface
supporting partitioning of file data among processes and a collective interface supporting complete
transfers of global data structures between process memories and files. Additionally, further
efficiencies can be gained via support for asynchronous input/output, strided accesses to data, and
control over physical file layout on storage devices. This scenario motivated the inclusion in the MPI-2
standard of a custom interface in order to support more elaborated parallel input/output operations.
The MPI specification for parallel input/output revolves around the use objects called files. As defined
by MPI, files are not just contiguous byte streams. Instead, they are regarded as ordered collections of
typed data items. MPI supports sequential or random access to any integral set of these items.
Furthermore, files are opened collectively by a group of processes.
The common patterns for accessing a shared file (broadcast, scatter, gather, reduction) is expressed by
using user-defined datatypes. Compared to the communication patterns of point-to-point and collective
communications, this approach has the advantage of added flexibility and expressiveness. Data access
operations (read and write) are defined for different kinds of positioning (using explicit offsets,
individual file pointers, and shared file pointers), coordination (non-collective and collective), and
synchronism (blocking, nonblocking, and split collective with begin/end phases).
In MPI for Python, all MPI input/output operations are performed through instances of the File class.
File handles are obtained by calling the File.Open method at all processes within a communicator and
providing a file name and the intended access mode. After use, they must be closed by calling the
File.Close method. Files even can be deleted by calling method File.Delete.
After creation, files are typically associated with a per-process view. The view defines the current set
of data visible and accessible from an open file as an ordered set of elementary datatypes. This data
layout can be set and queried with the File.Set_view and File.Get_view methods respectively.
Actual input/output operations are achieved by many methods combining read and write calls with different
behavior regarding positioning, coordination, and synchronism. Summing up, MPI for Python provides the
thirty (30) methods defined in MPI-2 for reading from or writing to files using explicit offsets or file
pointers (individual or shared), in blocking or nonblocking and collective or noncollective versions.
Environmental Management
Initialization and Exit
Module functions Init or Init_thread and Finalize provide MPI initialization and finalization
respectively. Module functions Is_initialized and Is_finalized provide the respective tests for
initialization and finalization.
NOTE:
MPI_Init() or MPI_Init_thread() is actually called when you import the MPI module from the mpi4py
package, but only if MPI is not already initialized. In such case, calling Init or Init_thread from
Python is expected to generate an MPI error, and in turn an exception will be raised.
NOTE:
MPI_Finalize() is registered (by using Python C/API function Py_AtExit()) for being automatically
called when Python processes exit, but only if mpi4py actually initialized MPI. Therefore, there is no
need to call Finalize from Python to ensure MPI finalization.
Implementation Information
• The MPI version number can be retrieved from module function Get_version. It returns a two-integer
tuple (version, subversion).
• The Get_processor_name function can be used to access the processor name.
• The values of predefined attributes attached to the world communicator can be obtained by calling the
Comm.Get_attr method within the COMM_WORLD instance.
Timers
MPI timer functionalities are available through the Wtime and Wtick functions.
Error Handling
In order to facilitate handle sharing with other Python modules interfacing MPI-based parallel libraries,
the predefined MPI error handlers ERRORS_RETURN and ERRORS_ARE_FATAL can be assigned to and retrieved
from communicators using methods Comm.Set_errhandler and Comm.Get_errhandler, and similarly for windows
and files. New custom error handlers can be created with Comm.Create_errhandler.
When the predefined error handler ERRORS_RETURN is set, errors returned from MPI calls within Python code
will raise an instance of the exception class Exception, which is a subclass of the standard Python
exception RuntimeError.
NOTE:
After import, mpi4py overrides the default MPI rules governing inheritance of error handlers. The
ERRORS_RETURN error handler is set in the predefined COMM_SELF and COMM_WORLD communicators, as well
as any new Comm, Win, or File instance created through mpi4py. If you ever pass such handles to
C/C++/Fortran library code, it is recommended to set the ERRORS_ARE_FATAL error handler on them to
ensure MPI errors do not pass silently.
WARNING:
Importing with from mpi4py.MPI import * will cause a name clashing with the standard Python Exception
base class.
TUTORIAL
WARNING:
Under construction. Contributions very welcome!
TIP:
Rolf Rabenseifner at HLRS developed a comprehensive MPI-3.1/4.0 course with slides and a large set of
exercises including solutions. This material is available online for self-study. The slides and
exercises show the C, Fortran, and Python (mpi4py) interfaces. For performance reasons, most Python
exercises use NumPy arrays and communication routines involving buffer-like objects.
TIP:
Victor Eijkhout at TACC authored the book Parallel Programming for Science and Engineering. This book
is available online in PDF and HTML formats. The book covers parallel programming with MPI and OpenMP
in C/C++ and Fortran, and MPI in Python using mpi4py.
MPI for Python supports convenient, pickle-based communication of generic Python object as well as fast,
near C-speed, direct array data communication of buffer-provider objects (e.g., NumPy arrays).
• Communication of generic Python objects
You have to use methods with all-lowercase names, like Comm.send, Comm.recv, Comm.bcast, Comm.scatter,
Comm.gather . An object to be sent is passed as a parameter to the communication call, and the received
object is simply the return value.
The Comm.isend and Comm.irecv methods return Request instances; completion of these methods can be
managed using the Request.test and Request.wait methods.
The Comm.recv and Comm.irecv methods may be passed a buffer object that can be repeatedly used to
receive messages avoiding internal memory allocation. This buffer must be sufficiently large to
accommodate the transmitted messages; hence, any buffer passed to Comm.recv or Comm.irecv must be at
least as long as the pickled data transmitted to the receiver.
Collective calls like Comm.scatter, Comm.gather, Comm.allgather, Comm.alltoall expect a single value or
a sequence of Comm.size elements at the root or all process. They return a single value, a list of
Comm.size elements, or None.
NOTE:
MPI for Python uses the highest protocol version available in the Python runtime (see the ‐
HIGHEST_PROTOCOL constant in the pickle module). The default protocol can be changed at import time
by setting the MPI4PY_PICKLE_PROTOCOL environment variable, or at runtime by assigning a different
value to the PROTOCOL attribute of the pickle object within the MPI module.
• Communication of buffer-like objects
You have to use method names starting with an upper-case letter, like Comm.Send, Comm.Recv, Comm.Bcast,
Comm.Scatter, Comm.Gather.
In general, buffer arguments to these calls must be explicitly specified by using a 2/3-list/tuple like
[data, MPI.DOUBLE], or [data, count, MPI.DOUBLE] (the former one uses the byte-size of data and the
extent of the MPI datatype to define count).
For vector collectives communication operations like Comm.Scatterv and Comm.Gatherv, buffer arguments
are specified as [data, count, displ, datatype], where count and displ are sequences of integral
values.
Automatic MPI datatype discovery for NumPy/GPU arrays and PEP-3118 buffers is supported, but limited to
basic C types (all C/C99-native signed/unsigned integral types and single/double precision real/complex
floating types) and availability of matching datatypes in the underlying MPI implementation. In this
case, the buffer-provider object can be passed directly as a buffer argument, the count and MPI
datatype will be inferred.
If mpi4py is built against a GPU-aware MPI implementation, GPU arrays can be passed to upper-case
methods as long as they have either the __dlpack__ and __dlpack_device__ methods or the
__cuda_array_interface__ attribute that are compliant with the respective standard specifications.
Moreover, only C-contiguous or Fortran-contiguous GPU arrays are supported. It is important to note
that GPU buffers must be fully ready before any MPI routines operate on them to avoid race conditions.
This can be ensured by using the synchronization API of your array library. mpi4py does not have access
to any GPU-specific functionality and thus cannot perform this operation automatically for users.
Running Python scripts with MPI
Most MPI programs can be run with the command mpiexec. In practice, running Python programs looks like:
$ mpiexec -n 4 python script.py
to run the program with 4 processors.
Point-to-Point Communication
• Python objects (pickle under the hood):
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
if rank == 0:
data = {'a': 7, 'b': 3.14}
comm.send(data, dest=1, tag=11)
elif rank == 1:
data = comm.recv(source=0, tag=11)
• Python objects with non-blocking communication:
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
if rank == 0:
data = {'a': 7, 'b': 3.14}
req = comm.isend(data, dest=1, tag=11)
req.wait()
elif rank == 1:
req = comm.irecv(source=0, tag=11)
data = req.wait()
• NumPy arrays (the fast way!):
from mpi4py import MPI
import numpy
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
# passing MPI datatypes explicitly
if rank == 0:
data = numpy.arange(1000, dtype='i')
comm.Send([data, MPI.INT], dest=1, tag=77)
elif rank == 1:
data = numpy.empty(1000, dtype='i')
comm.Recv([data, MPI.INT], source=0, tag=77)
# automatic MPI datatype discovery
if rank == 0:
data = numpy.arange(100, dtype=numpy.float64)
comm.Send(data, dest=1, tag=13)
elif rank == 1:
data = numpy.empty(100, dtype=numpy.float64)
comm.Recv(data, source=0, tag=13)
Collective Communication
• Broadcasting a Python dictionary:
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
if rank == 0:
data = {'key1' : [7, 2.72, 2+3j],
'key2' : ( 'abc', 'xyz')}
else:
data = None
data = comm.bcast(data, root=0)
• Scattering Python objects:
from mpi4py import MPI
comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()
if rank == 0:
data = [(i+1)**2 for i in range(size)]
else:
data = None
data = comm.scatter(data, root=0)
assert data == (rank+1)**2
• Gathering Python objects:
from mpi4py import MPI
comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()
data = (rank+1)**2
data = comm.gather(data, root=0)
if rank == 0:
for i in range(size):
assert data[i] == (i+1)**2
else:
assert data is None
• Broadcasting a NumPy array:
from mpi4py import MPI
import numpy as np
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
if rank == 0:
data = np.arange(100, dtype='i')
else:
data = np.empty(100, dtype='i')
comm.Bcast(data, root=0)
for i in range(100):
assert data[i] == i
• Scattering NumPy arrays:
from mpi4py import MPI
import numpy as np
comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()
sendbuf = None
if rank == 0:
sendbuf = np.empty([size, 100], dtype='i')
sendbuf.T[:,:] = range(size)
recvbuf = np.empty(100, dtype='i')
comm.Scatter(sendbuf, recvbuf, root=0)
assert np.allclose(recvbuf, rank)
• Gathering NumPy arrays:
from mpi4py import MPI
import numpy as np
comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()
sendbuf = np.zeros(100, dtype='i') + rank
recvbuf = None
if rank == 0:
recvbuf = np.empty([size, 100], dtype='i')
comm.Gather(sendbuf, recvbuf, root=0)
if rank == 0:
for i in range(size):
assert np.allclose(recvbuf[i,:], i)
• Parallel matrix-vector product:
from mpi4py import MPI
import numpy
def matvec(comm, A, x):
m = A.shape[0] # local rows
p = comm.Get_size()
xg = numpy.zeros(m*p, dtype='d')
comm.Allgather([x, MPI.DOUBLE],
[xg, MPI.DOUBLE])
y = numpy.dot(A, xg)
return y
Input/Output (MPI-IO)
• Collective I/O with NumPy arrays:
from mpi4py import MPI
import numpy as np
amode = MPI.MODE_WRONLY|MPI.MODE_CREATE
comm = MPI.COMM_WORLD
fh = MPI.File.Open(comm, "./datafile.contig", amode)
buffer = np.empty(10, dtype=np.int)
buffer[:] = comm.Get_rank()
offset = comm.Get_rank()*buffer.nbytes
fh.Write_at_all(offset, buffer)
fh.Close()
• Non-contiguous Collective I/O with NumPy arrays and datatypes:
from mpi4py import MPI
import numpy as np
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
size = comm.Get_size()
amode = MPI.MODE_WRONLY|MPI.MODE_CREATE
fh = MPI.File.Open(comm, "./datafile.noncontig", amode)
item_count = 10
buffer = np.empty(item_count, dtype='i')
buffer[:] = rank
filetype = MPI.INT.Create_vector(item_count, 1, size)
filetype.Commit()
displacement = MPI.INT.Get_size()*rank
fh.Set_view(displacement, filetype=filetype)
fh.Write_all(buffer)
filetype.Free()
fh.Close()
Dynamic Process Management
• Compute Pi - Master (or parent, or client) side:
#!/usr/bin/env python
from mpi4py import MPI
import numpy
import sys
comm = MPI.COMM_SELF.Spawn(sys.executable,
args=['cpi.py'],
maxprocs=5)
N = numpy.array(100, 'i')
comm.Bcast([N, MPI.INT], root=MPI.ROOT)
PI = numpy.array(0.0, 'd')
comm.Reduce(None, [PI, MPI.DOUBLE],
op=MPI.SUM, root=MPI.ROOT)
print(PI)
comm.Disconnect()
• Compute Pi - Worker (or child, or server) side:
#!/usr/bin/env python
from mpi4py import MPI
import numpy
comm = MPI.Comm.Get_parent()
size = comm.Get_size()
rank = comm.Get_rank()
N = numpy.array(0, dtype='i')
comm.Bcast([N, MPI.INT], root=0)
h = 1.0 / N; s = 0.0
for i in range(rank, N, size):
x = h * (i + 0.5)
s += 4.0 / (1.0 + x**2)
PI = numpy.array(s * h, dtype='d')
comm.Reduce([PI, MPI.DOUBLE], None,
op=MPI.SUM, root=0)
comm.Disconnect()
GPU-aware MPI + Python GPU arrays
• Reduce-to-all CuPy arrays:
from mpi4py import MPI
import cupy as cp
comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()
sendbuf = cp.arange(10, dtype='i')
recvbuf = cp.empty_like(sendbuf)
cp.cuda.get_current_stream().synchronize()
comm.Allreduce(sendbuf, recvbuf)
assert cp.allclose(recvbuf, sendbuf*size)
One-Sided Communication (RMA)
• Read from (write to) the entire RMA window:
import numpy as np
from mpi4py import MPI
from mpi4py.util import dtlib
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
datatype = MPI.FLOAT
np_dtype = dtlib.to_numpy_dtype(datatype)
itemsize = datatype.Get_size()
N = 10
win_size = N * itemsize if rank == 0 else 0
win = MPI.Win.Allocate(win_size, comm=comm)
buf = np.empty(N, dtype=np_dtype)
if rank == 0:
buf.fill(42)
win.Lock(rank=0)
win.Put(buf, target_rank=0)
win.Unlock(rank=0)
comm.Barrier()
else:
comm.Barrier()
win.Lock(rank=0)
win.Get(buf, target_rank=0)
win.Unlock(rank=0)
assert np.all(buf == 42)
• Accessing a part of the RMA window using the target argument, which is defined as (offset, count,
datatype):
import numpy as np
from mpi4py import MPI
from mpi4py.util import dtlib
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
datatype = MPI.FLOAT
np_dtype = dtlib.to_numpy_dtype(datatype)
itemsize = datatype.Get_size()
N = comm.Get_size() + 1
win_size = N * itemsize if rank == 0 else 0
win = MPI.Win.Allocate(
size=win_size,
disp_unit=itemsize,
comm=comm,
)
if rank == 0:
mem = np.frombuffer(win, dtype=np_dtype)
mem[:] = np.arange(len(mem), dtype=np_dtype)
comm.Barrier()
buf = np.zeros(3, dtype=np_dtype)
target = (rank, 2, datatype)
win.Lock(rank=0)
win.Get(buf, target_rank=0, target=target)
win.Unlock(rank=0)
assert np.all(buf == [rank, rank+1, 0])
Wrapping with SWIG
• C source:
/* file: helloworld.c */
void sayhello(MPI_Comm comm)
{
int size, rank;
MPI_Comm_size(comm, &size);
MPI_Comm_rank(comm, &rank);
printf("Hello, World! "
"I am process %d of %d.\n",
rank, size);
}
• SWIG interface file:
// file: helloworld.i
%module helloworld
%{
#include <mpi.h>
#include "helloworld.c"
}%
%include mpi4py/mpi4py.i
%mpi4py_typemap(Comm, MPI_Comm);
void sayhello(MPI_Comm comm);
• Try it in the Python prompt:
>>> from mpi4py import MPI
>>> import helloworld
>>> helloworld.sayhello(MPI.COMM_WORLD)
Hello, World! I am process 0 of 1.
Wrapping with F2Py
• Fortran 90 source:
! file: helloworld.f90
subroutine sayhello(comm)
use mpi
implicit none
integer :: comm, rank, size, ierr
call MPI_Comm_size(comm, size, ierr)
call MPI_Comm_rank(comm, rank, ierr)
print *, 'Hello, World! I am process ',rank,' of ',size,'.'
end subroutine sayhello
• Compiling example using f2py
$ f2py -c --f90exec=mpif90 helloworld.f90 -m helloworld
• Try it in the Python prompt:
>>> from mpi4py import MPI
>>> import helloworld
>>> fcomm = MPI.COMM_WORLD.py2f()
>>> helloworld.sayhello(fcomm)
Hello, World! I am process 0 of 1.
MPI4PY
The MPI for Python package.
The Message Passing Interface (MPI) is a standardized and portable message-passing system designed to
function on a wide variety of parallel computers. The MPI standard defines the syntax and semantics of
library routines and allows users to write portable programs in the main scientific programming languages
(Fortran, C, or C++). Since its release, the MPI specification has become the leading standard for
message-passing libraries for parallel computers.
MPI for Python provides MPI bindings for the Python programming language, allowing any Python program to
exploit multiple processors. This package build on the MPI specification and provides an object oriented
interface which closely follows MPI-2 C++ bindings.
Runtime configuration options
mpi4py.rc
This object has attributes exposing runtime configuration options that become effective at import
time of the MPI module.
Attributes Summary
┌──────────────┬───────────────────────────────────────┐
│ initialize │ Automatic MPI initialization at │
│ │ import │
├──────────────┼───────────────────────────────────────┤
│ threads │ Request initialization with thread │
│ │ support │
├──────────────┼───────────────────────────────────────┤
│ thread_level │ Level of thread support to request │
├──────────────┼───────────────────────────────────────┤
│ finalize │ Automatic MPI finalization at exit │
├──────────────┼───────────────────────────────────────┤
│ fast_reduce │ Use tree-based reductions for objects │
├──────────────┼───────────────────────────────────────┤
│ recv_mprobe │ Use matched probes to receive objects │
├──────────────┼───────────────────────────────────────┤
│ irecv_bufsz │ Default buffer size in bytes for │
│ │ irecv() │
├──────────────┼───────────────────────────────────────┤
│ errors │ Error handling policy │
└──────────────┴───────────────────────────────────────┘
Attributes Documentation
mpi4py.rc.initialize
Automatic MPI initialization at import.
Type bool
Default
True
SEE ALSO:
MPI4PY_RC_INITIALIZE
mpi4py.rc.threads
Request initialization with thread support.
Type bool
Default
True
SEE ALSO:
MPI4PY_RC_THREADS
mpi4py.rc.thread_level
Level of thread support to request.
Type str
Default
"multiple"
Choices
"multiple", "serialized", "funneled", "single"
SEE ALSO:
MPI4PY_RC_THREAD_LEVEL
mpi4py.rc.finalize
Automatic MPI finalization at exit.
Type None or bool
Default
None
SEE ALSO:
MPI4PY_RC_FINALIZE
mpi4py.rc.fast_reduce
Use tree-based reductions for objects.
Type bool
Default
True
SEE ALSO:
MPI4PY_RC_FAST_REDUCE
mpi4py.rc.recv_mprobe
Use matched probes to receive objects.
Type bool
Default
True
SEE ALSO:
MPI4PY_RC_RECV_MPROBE
mpi4py.rc.irecv_bufsz
Default buffer size in bytes for irecv().
Type int
Default
32768
SEE ALSO:
MPI4PY_RC_IRECV_BUFSZ
Added in version 4.0.0.
mpi4py.rc.errors
Error handling policy.
Type str
Default
"exception"
Choices
"exception", "default", "abort", "fatal"
SEE ALSO:
MPI4PY_RC_ERRORS
Example
MPI for Python features automatic initialization and finalization of the MPI execution environment. By
using the mpi4py.rc object, MPI initialization and finalization can be handled programmatically:
import mpi4py
mpi4py.rc.initialize = False # do not initialize MPI automatically
mpi4py.rc.finalize = False # do not finalize MPI automatically
from mpi4py import MPI # import the 'MPI' module
MPI.Init() # manual initialization of the MPI environment
... # your finest code here ...
MPI.Finalize() # manual finalization of the MPI environment
Environment variables
The following environment variables override the corresponding attributes of the mpi4py.rc and MPI.pickle
objects at import time of the MPI module.
NOTE:
For variables of boolean type, accepted values are 0 and 1 (interpreted as False and True,
respectively), and strings specifying a YAML boolean value (case-insensitive).
MPI4PY_RC_INITIALIZE
Type bool
Default
True
Whether to automatically initialize MPI at import time of the mpi4py.MPI module.
SEE ALSO:
mpi4py.rc.initialize
Added in version 4.0.0.
MPI4PY_RC_FINALIZE
Type None | bool
Default
None
Choices
None, True, False
Whether to automatically finalize MPI at exit time of the Python process.
SEE ALSO:
mpi4py.rc.finalize
Added in version 4.0.0.
MPI4PY_RC_THREADS
Type bool
Default
True
Whether to initialize MPI with thread support.
SEE ALSO:
mpi4py.rc.threads
Added in version 3.1.0.
MPI4PY_RC_THREAD_LEVEL
Default
"multiple"
Choices
"single", "funneled", "serialized", "multiple"
The level of required thread support.
SEE ALSO:
mpi4py.rc.thread_level
Added in version 3.1.0.
MPI4PY_RC_FAST_REDUCE
Type bool
Default
True
Whether to use tree-based reductions for objects.
SEE ALSO:
mpi4py.rc.fast_reduce
Added in version 3.1.0.
MPI4PY_RC_RECV_MPROBE
Type bool
Default
True
Whether to use matched probes to receive objects.
SEE ALSO:
mpi4py.rc.recv_mprobe
MPI4PY_RC_IRECV_BUFSZ
Type int
Default
32768
Default buffer size in bytes for irecv().
SEE ALSO:
mpi4py.rc.irecv_bufsz
Added in version 4.0.0.
MPI4PY_RC_ERRORS
Default
"exception"
Choices
"exception", "default", "abort", "fatal"
Controls default MPI error handling policy.
SEE ALSO:
mpi4py.rc.errors
Added in version 3.1.0.
MPI4PY_PICKLE_PROTOCOL
Type int
Default
pickle.HIGHEST_PROTOCOL
Controls the default pickle protocol to use when communicating Python objects.
SEE ALSO:
PROTOCOL attribute of the MPI.pickle object within the MPI module.
Added in version 3.1.0.
MPI4PY_PICKLE_THRESHOLD
Type int
Default
262144
Controls the default buffer size threshold for switching from in-band to out-of-band buffer
handling when using pickle protocol version 5 or higher.
SEE ALSO:
THRESHOLD attribute of the MPI.pickle object within the MPI module.
Added in version 3.1.2.
Miscellaneous functions
mpi4py.profile(name, *, path=None)
Support for the MPI profiling interface.
Parameters
• name (str) – Name of the profiler library to load.
• path (sequence of str, optional) – Additional paths to search for the profiler.
Return type
None
mpi4py.get_include()
Return the directory in the package that contains header files.
Extension modules that need to compile against mpi4py should use this function to locate the
appropriate include directory. Using Python distutils (or perhaps NumPy distutils):
import mpi4py
Extension('extension_name', ...
include_dirs=[..., mpi4py.get_include()])
Return type
str
mpi4py.get_config()
Return a dictionary with information about MPI.
Changed in version 4.0.0: By default, this function returns an empty dictionary. However,
downstream packagers and distributors may alter such behavior. To that end, MPI information must
be provided under an mpi section within a UTF-8 encoded INI-style configuration file mpi.cfg
located at the top-level package directory. The configuration file is read and parsed using the ‐
configparser module.
Return type
dict[str, str]
MPI4PY.MPI
Classes
Ancillary
┌──────────┬──────────────────────────────┐
│ Datatype │ Datatype object. │
├──────────┼──────────────────────────────┤
│ Status │ Status object. │
├──────────┼──────────────────────────────┤
│ Request │ Request handler. │
├──────────┼──────────────────────────────┤
│ Prequest │ Persistent request handler. │
├──────────┼──────────────────────────────┤
│ Grequest │ Generalized request handler. │
├──────────┼──────────────────────────────┤
│ Op │ Reduction operation. │
├──────────┼──────────────────────────────┤
│ Group │ Group of processes. │
├──────────┼──────────────────────────────┤
│ Info │ Info object. │
├──────────┼──────────────────────────────┤
│ Session │ Session context. │
└──────────┴──────────────────────────────┘
Communication
┌───────────────┬───────────────────────────────────────┐
│ Comm │ Communication context. │
├───────────────┼───────────────────────────────────────┤
│ Intracomm │ Intracommunicator. │
├───────────────┼───────────────────────────────────────┤
│ Topocomm │ Topology intracommunicator. │
├───────────────┼───────────────────────────────────────┤
│ Cartcomm │ Cartesian topology intracommunicator. │
├───────────────┼───────────────────────────────────────┤
│ Graphcomm │ General graph topology │
│ │ intracommunicator. │
├───────────────┼───────────────────────────────────────┤
│ Distgraphcomm │ Distributed graph topology │
│ │ intracommunicator. │
├───────────────┼───────────────────────────────────────┤
│ Intercomm │ Intercommunicator. │
├───────────────┼───────────────────────────────────────┤
│ Message │ Matched message. │
└───────────────┴───────────────────────────────────────┘
One-sided operations
┌─────┬───────────────────────────────┐
│ Win │ Remote memory access context. │
└─────┴───────────────────────────────┘
Input/Output
┌──────┬───────────────────┐
│ File │ File I/O context. │
└──────┴───────────────────┘
Error handling
┌────────────┬──────────────────┐
│ Errhandler │ Error handler. │
├────────────┼──────────────────┤
│ Exception │ Exception class. │
└────────────┴──────────────────┘
Auxiliary
┌────────┬─────────────────────────────────┐
│ Pickle │ Pickle/unpickle Python objects. │
├────────┼─────────────────────────────────┤
│ buffer │ Buffer. │
└────────┴─────────────────────────────────┘
Functions
Version inquiry
┌───────────────────────┬───────────────────────────────────────┐
│ Get_version() │ Obtain the version number of the MPI │
│ │ standard. │
├───────────────────────┼───────────────────────────────────────┤
│ Get_library_version() │ Obtain the version string of the MPI │
│ │ library. │
└───────────────────────┴───────────────────────────────────────┘
Initialization and finalization
┌─────────────────────────┬───────────────────────────────────────┐
│ Init() │ Initialize the MPI execution │
│ │ environment. │
├─────────────────────────┼───────────────────────────────────────┤
│ Init_thread([required]) │ Initialize the MPI execution │
│ │ environment. │
├─────────────────────────┼───────────────────────────────────────┤
│ Finalize() │ Terminate the MPI execution │
│ │ environment. │
├─────────────────────────┼───────────────────────────────────────┤
│ Is_initialized() │ Indicate whether Init has been │
│ │ called. │
├─────────────────────────┼───────────────────────────────────────┤
│ Is_finalized() │ Indicate whether Finalize has │
│ │ completed. │
├─────────────────────────┼───────────────────────────────────────┤
│ Query_thread() │ Return the level of thread support │
│ │ provided by the MPI library. │
├─────────────────────────┼───────────────────────────────────────┤
│ Is_thread_main() │ Indicate whether this thread called │
│ │ Init or Init_thread. │
└─────────────────────────┴───────────────────────────────────────┘
Memory allocation
┌─────────────────────────┬───────────────────────────────────────┐
│ Alloc_mem(size[, info]) │ Allocate memory for message passing │
│ │ and remote memory access. │
├─────────────────────────┼───────────────────────────────────────┤
│ Free_mem(mem) │ Free memory allocated with Alloc_mem. │
└─────────────────────────┴───────────────────────────────────────┘
Address manipulation
┌─────────────────────────┬───────────────────────────────────────┐
│ Get_address(location) │ Get the address of a location in │
│ │ memory. │
├─────────────────────────┼───────────────────────────────────────┤
│ Aint_add(base, disp) │ Return the sum of base address and │
│ │ displacement. │
├─────────────────────────┼───────────────────────────────────────┤
│ Aint_diff(addr1, addr2) │ Return the difference between │
│ │ absolute addresses. │
└─────────────────────────┴───────────────────────────────────────┘
Timer
┌─────────┬───────────────────────────────────────┐
│ Wtick() │ Return the resolution of Wtime. │
├─────────┼───────────────────────────────────────┤
│ Wtime() │ Return an elapsed time on the calling │
│ │ processor. │
└─────────┴───────────────────────────────────────┘
Error handling
┌─────────────────────────────────────┬───────────────────────────────────────┐
│ Get_error_class(errorcode) │ Convert an error code into an error │
│ │ class. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Get_error_string(errorcode) │ Return the error string for a given │
│ │ error class or error code. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Add_error_class() │ Add an error class to the known error │
│ │ classes. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Add_error_code(errorclass) │ Add an error code to an error class. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Add_error_string(errorcode, string) │ Associate an error string with an │
│ │ error class or error code. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Remove_error_class(errorclass) │ Remove an error class from the known │
│ │ error classes. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Remove_error_code(errorcode) │ Remove an error code from the known │
│ │ error codes. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Remove_error_string(errorcode) │ Remove error string association from │
│ │ error class or error code. │
└─────────────────────────────────────┴───────────────────────────────────────┘
Dynamic process management
┌───────────────────────────────────┬───────────────────────────────────────┐
│ Open_port([info]) │ Return an address used to connect │
│ │ group of processes. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Close_port(port_name) │ Close a port. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Publish_name(service_name, │ Publish a service name. │
│ port_name[, info]) │ │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Unpublish_name(service_name, │ Unpublish a service name. │
│ port_name[, info]) │ │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Lookup_name(service_name[, info]) │ Lookup a port name given a service │
│ │ name. │
└───────────────────────────────────┴───────────────────────────────────────┘
Miscellanea
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Attach_buffer(buf) │ Attach a user-provided buffer for │
│ │ sending in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Detach_buffer() │ Remove an existing attached buffer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush_buffer() │ Block until all buffered messages │
│ │ have been transmitted. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iflush_buffer() │ Nonblocking flush for buffered │
│ │ messages. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Compute_dims(nnodes, dims) │ Return a balanced distribution of │
│ │ processes per coordinate direction. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_processor_name() │ Obtain the name of the calling │
│ │ processor. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Register_datarep(datarep, read_fn, │ Register user-defined data │
│ write_fn, ...) │ representations. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Pcontrol(level) │ Control profiling. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Utilities
┌──────────────┬───────────────────────────────────────┐
│ get_vendor() │ Information about the underlying MPI │
│ │ implementation. │
└──────────────┴───────────────────────────────────────┘
Attributes
┌────────────────────────────┬───────────────────────────────────────┐
│ UNDEFINED │ Constant UNDEFINED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ANY_SOURCE │ Constant ANY_SOURCE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ANY_TAG │ Constant ANY_TAG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ PROC_NULL │ Constant PROC_NULL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ROOT │ Constant ROOT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ BOTTOM │ Constant BOTTOM of type BottomType │
├────────────────────────────┼───────────────────────────────────────┤
│ IN_PLACE │ Constant IN_PLACE of type InPlaceType │
├────────────────────────────┼───────────────────────────────────────┤
│ BUFFER_AUTOMATIC │ Constant BUFFER_AUTOMATIC of type │
│ │ BufferAutomaticType │
├────────────────────────────┼───────────────────────────────────────┤
│ KEYVAL_INVALID │ Constant KEYVAL_INVALID of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ TAG_UB │ Constant TAG_UB of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ IO │ Constant IO of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WTIME_IS_GLOBAL │ Constant WTIME_IS_GLOBAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ UNIVERSE_SIZE │ Constant UNIVERSE_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ APPNUM │ Constant APPNUM of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ LASTUSEDCODE │ Constant LASTUSEDCODE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_BASE │ Constant WIN_BASE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_SIZE │ Constant WIN_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_DISP_UNIT │ Constant WIN_DISP_UNIT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_CREATE_FLAVOR │ Constant WIN_CREATE_FLAVOR of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR │ Constant WIN_FLAVOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_MODEL │ Constant WIN_MODEL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SUCCESS │ Constant SUCCESS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_LASTCODE │ Constant ERR_LASTCODE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_COMM │ Constant ERR_COMM of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_GROUP │ Constant ERR_GROUP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TYPE │ Constant ERR_TYPE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_REQUEST │ Constant ERR_REQUEST of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_OP │ Constant ERR_OP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ERRHANDLER │ Constant ERR_ERRHANDLER of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_BUFFER │ Constant ERR_BUFFER of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_COUNT │ Constant ERR_COUNT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TAG │ Constant ERR_TAG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RANK │ Constant ERR_RANK of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ROOT │ Constant ERR_ROOT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TRUNCATE │ Constant ERR_TRUNCATE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_IN_STATUS │ Constant ERR_IN_STATUS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PENDING │ Constant ERR_PENDING of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TOPOLOGY │ Constant ERR_TOPOLOGY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_DIMS │ Constant ERR_DIMS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ARG │ Constant ERR_ARG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_OTHER │ Constant ERR_OTHER of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_UNKNOWN │ Constant ERR_UNKNOWN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INTERN │ Constant ERR_INTERN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO │ Constant ERR_INFO of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_FILE │ Constant ERR_FILE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_WIN │ Constant ERR_WIN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_KEYVAL │ Constant ERR_KEYVAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO_KEY │ Constant ERR_INFO_KEY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO_VALUE │ Constant ERR_INFO_VALUE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO_NOKEY │ Constant ERR_INFO_NOKEY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ACCESS │ Constant ERR_ACCESS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_AMODE │ Constant ERR_AMODE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_BAD_FILE │ Constant ERR_BAD_FILE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_FILE_EXISTS │ Constant ERR_FILE_EXISTS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_FILE_IN_USE │ Constant ERR_FILE_IN_USE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NO_SPACE │ Constant ERR_NO_SPACE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NO_SUCH_FILE │ Constant ERR_NO_SUCH_FILE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_IO │ Constant ERR_IO of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_READ_ONLY │ Constant ERR_READ_ONLY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_CONVERSION │ Constant ERR_CONVERSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_DUP_DATAREP │ Constant ERR_DUP_DATAREP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_UNSUPPORTED_DATAREP │ Constant ERR_UNSUPPORTED_DATAREP of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_UNSUPPORTED_OPERATION │ Constant ERR_UNSUPPORTED_OPERATION of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NAME │ Constant ERR_NAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NO_MEM │ Constant ERR_NO_MEM of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NOT_SAME │ Constant ERR_NOT_SAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PORT │ Constant ERR_PORT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_QUOTA │ Constant ERR_QUOTA of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SERVICE │ Constant ERR_SERVICE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SPAWN │ Constant ERR_SPAWN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_BASE │ Constant ERR_BASE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SIZE │ Constant ERR_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_DISP │ Constant ERR_DISP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ASSERT │ Constant ERR_ASSERT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_LOCKTYPE │ Constant ERR_LOCKTYPE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_CONFLICT │ Constant ERR_RMA_CONFLICT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_SYNC │ Constant ERR_RMA_SYNC of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_RANGE │ Constant ERR_RMA_RANGE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_ATTACH │ Constant ERR_RMA_ATTACH of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_SHARED │ Constant ERR_RMA_SHARED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_FLAVOR │ Constant ERR_RMA_FLAVOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ORDER_C │ Constant ORDER_C of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ORDER_F │ Constant ORDER_F of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ORDER_FORTRAN │ Constant ORDER_FORTRAN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ TYPECLASS_INTEGER │ Constant TYPECLASS_INTEGER of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ TYPECLASS_REAL │ Constant TYPECLASS_REAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ TYPECLASS_COMPLEX │ Constant TYPECLASS_COMPLEX of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_NONE │ Constant DISTRIBUTE_NONE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_BLOCK │ Constant DISTRIBUTE_BLOCK of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_CYCLIC │ Constant DISTRIBUTE_CYCLIC of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_DFLT_DARG │ Constant DISTRIBUTE_DFLT_DARG of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_NAMED │ Constant COMBINER_NAMED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_DUP │ Constant COMBINER_DUP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_CONTIGUOUS │ Constant COMBINER_CONTIGUOUS of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_VECTOR │ Constant COMBINER_VECTOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_HVECTOR │ Constant COMBINER_HVECTOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_INDEXED │ Constant COMBINER_INDEXED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_HINDEXED │ Constant COMBINER_HINDEXED of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_INDEXED_BLOCK │ Constant COMBINER_INDEXED_BLOCK of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_HINDEXED_BLOCK │ Constant COMBINER_HINDEXED_BLOCK of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_STRUCT │ Constant COMBINER_STRUCT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_SUBARRAY │ Constant COMBINER_SUBARRAY of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_DARRAY │ Constant COMBINER_DARRAY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_RESIZED │ Constant COMBINER_RESIZED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_VALUE_INDEX │ Constant COMBINER_VALUE_INDEX of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_F90_REAL │ Constant COMBINER_F90_REAL of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_F90_COMPLEX │ Constant COMBINER_F90_COMPLEX of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_F90_INTEGER │ Constant COMBINER_F90_INTEGER of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ IDENT │ Constant IDENT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ CONGRUENT │ Constant CONGRUENT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SIMILAR │ Constant SIMILAR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ UNEQUAL │ Constant UNEQUAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ CART │ Constant CART of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ GRAPH │ Constant GRAPH of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DIST_GRAPH │ Constant DIST_GRAPH of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ UNWEIGHTED │ Constant UNWEIGHTED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WEIGHTS_EMPTY │ Constant WEIGHTS_EMPTY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_TYPE_SHARED │ Constant COMM_TYPE_SHARED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ BSEND_OVERHEAD │ Constant BSEND_OVERHEAD of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_CREATE │ Constant WIN_FLAVOR_CREATE of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_ALLOCATE │ Constant WIN_FLAVOR_ALLOCATE of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_DYNAMIC │ Constant WIN_FLAVOR_DYNAMIC of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_SHARED │ Constant WIN_FLAVOR_SHARED of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_SEPARATE │ Constant WIN_SEPARATE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_UNIFIED │ Constant WIN_UNIFIED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOCHECK │ Constant MODE_NOCHECK of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOSTORE │ Constant MODE_NOSTORE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOPUT │ Constant MODE_NOPUT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOPRECEDE │ Constant MODE_NOPRECEDE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOSUCCEED │ Constant MODE_NOSUCCEED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ LOCK_EXCLUSIVE │ Constant LOCK_EXCLUSIVE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ LOCK_SHARED │ Constant LOCK_SHARED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_RDONLY │ Constant MODE_RDONLY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_WRONLY │ Constant MODE_WRONLY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_RDWR │ Constant MODE_RDWR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_CREATE │ Constant MODE_CREATE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_EXCL │ Constant MODE_EXCL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_DELETE_ON_CLOSE │ Constant MODE_DELETE_ON_CLOSE of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_UNIQUE_OPEN │ Constant MODE_UNIQUE_OPEN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_SEQUENTIAL │ Constant MODE_SEQUENTIAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_APPEND │ Constant MODE_APPEND of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SEEK_SET │ Constant SEEK_SET of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SEEK_CUR │ Constant SEEK_CUR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SEEK_END │ Constant SEEK_END of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISPLACEMENT_CURRENT │ Constant DISPLACEMENT_CURRENT of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISP_CUR │ Constant DISP_CUR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_SINGLE │ Constant THREAD_SINGLE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_FUNNELED │ Constant THREAD_FUNNELED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_SERIALIZED │ Constant THREAD_SERIALIZED of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_MULTIPLE │ Constant THREAD_MULTIPLE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ VERSION │ Constant VERSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SUBVERSION │ Constant SUBVERSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_PROCESSOR_NAME │ Constant MAX_PROCESSOR_NAME of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_ERROR_STRING │ Constant MAX_ERROR_STRING of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_PORT_NAME │ Constant MAX_PORT_NAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_INFO_KEY │ Constant MAX_INFO_KEY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_INFO_VAL │ Constant MAX_INFO_VAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_OBJECT_NAME │ Constant MAX_OBJECT_NAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_DATAREP_STRING │ Constant MAX_DATAREP_STRING of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_LIBRARY_VERSION_STRING │ Constant MAX_LIBRARY_VERSION_STRING │
│ │ of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DATATYPE_NULL │ Object DATATYPE_NULL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ PACKED │ Object PACKED of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ BYTE │ Object BYTE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ AINT │ Object AINT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ OFFSET │ Object OFFSET of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COUNT │ Object COUNT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CHAR │ Object CHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ WCHAR │ Object WCHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_CHAR │ Object SIGNED_CHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SHORT │ Object SHORT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT │ Object INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG │ Object LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_LONG │ Object LONG_LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_CHAR │ Object UNSIGNED_CHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_SHORT │ Object UNSIGNED_SHORT of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED │ Object UNSIGNED of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_LONG │ Object UNSIGNED_LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_LONG_LONG │ Object UNSIGNED_LONG_LONG of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ FLOAT │ Object FLOAT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE │ Object DOUBLE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_DOUBLE │ Object LONG_DOUBLE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_BOOL │ Object C_BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT8_T │ Object INT8_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT16_T │ Object INT16_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT32_T │ Object INT32_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT64_T │ Object INT64_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT8_T │ Object UINT8_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT16_T │ Object UINT16_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT32_T │ Object UINT32_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT64_T │ Object UINT64_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_COMPLEX │ Object C_COMPLEX of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_FLOAT_COMPLEX │ Object C_FLOAT_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_DOUBLE_COMPLEX │ Object C_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_LONG_DOUBLE_COMPLEX │ Object C_LONG_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_BOOL │ Object CXX_BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_FLOAT_COMPLEX │ Object CXX_FLOAT_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_DOUBLE_COMPLEX │ Object CXX_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_LONG_DOUBLE_COMPLEX │ Object CXX_LONG_DOUBLE_COMPLEX of │
│ │ type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SHORT_INT │ Object SHORT_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT_INT │ Object INT_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ TWOINT │ Object TWOINT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_INT │ Object LONG_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ FLOAT_INT │ Object FLOAT_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE_INT │ Object DOUBLE_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_DOUBLE_INT │ Object LONG_DOUBLE_INT of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CHARACTER │ Object CHARACTER of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL │ Object LOGICAL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER │ Object INTEGER of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL │ Object REAL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE_PRECISION │ Object DOUBLE_PRECISION of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX │ Object COMPLEX of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE_COMPLEX │ Object DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL1 │ Object LOGICAL1 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL2 │ Object LOGICAL2 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL4 │ Object LOGICAL4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL8 │ Object LOGICAL8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER1 │ Object INTEGER1 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER2 │ Object INTEGER2 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER4 │ Object INTEGER4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER8 │ Object INTEGER8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER16 │ Object INTEGER16 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL2 │ Object REAL2 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL4 │ Object REAL4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL8 │ Object REAL8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL16 │ Object REAL16 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX4 │ Object COMPLEX4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX8 │ Object COMPLEX8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX16 │ Object COMPLEX16 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX32 │ Object COMPLEX32 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_INT │ Object UNSIGNED_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_SHORT │ Object SIGNED_SHORT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_INT │ Object SIGNED_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_LONG │ Object SIGNED_LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_LONG_LONG │ Object SIGNED_LONG_LONG of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ BOOL │ Object BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT8_T │ Object SINT8_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT16_T │ Object SINT16_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT32_T │ Object SINT32_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT64_T │ Object SINT64_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_BOOL │ Object F_BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_INT │ Object F_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_FLOAT │ Object F_FLOAT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_DOUBLE │ Object F_DOUBLE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_COMPLEX │ Object F_COMPLEX of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_FLOAT_COMPLEX │ Object F_FLOAT_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_DOUBLE_COMPLEX │ Object F_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REQUEST_NULL │ Object REQUEST_NULL of type Request │
├────────────────────────────┼───────────────────────────────────────┤
│ MESSAGE_NULL │ Object MESSAGE_NULL of type Message │
├────────────────────────────┼───────────────────────────────────────┤
│ MESSAGE_NO_PROC │ Object MESSAGE_NO_PROC of type │
│ │ Message │
├────────────────────────────┼───────────────────────────────────────┤
│ OP_NULL │ Object OP_NULL of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX │ Object MAX of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MIN │ Object MIN of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ SUM │ Object SUM of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ PROD │ Object PROD of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ LAND │ Object LAND of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ BAND │ Object BAND of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ LOR │ Object LOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ BOR │ Object BOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ LXOR │ Object LXOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ BXOR │ Object BXOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MAXLOC │ Object MAXLOC of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MINLOC │ Object MINLOC of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ REPLACE │ Object REPLACE of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ NO_OP │ Object NO_OP of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ GROUP_NULL │ Object GROUP_NULL of type Group │
├────────────────────────────┼───────────────────────────────────────┤
│ GROUP_EMPTY │ Object GROUP_EMPTY of type Group │
├────────────────────────────┼───────────────────────────────────────┤
│ INFO_NULL │ Object INFO_NULL of type Info │
├────────────────────────────┼───────────────────────────────────────┤
│ INFO_ENV │ Object INFO_ENV of type Info │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRHANDLER_NULL │ Object ERRHANDLER_NULL of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRORS_RETURN │ Object ERRORS_RETURN of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRORS_ARE_FATAL │ Object ERRORS_ARE_FATAL of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_NULL │ Object COMM_NULL of type Comm │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_SELF │ Object COMM_SELF of type Intracomm │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_WORLD │ Object COMM_WORLD of type Intracomm │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_NULL │ Object WIN_NULL of type Win │
├────────────────────────────┼───────────────────────────────────────┤
│ FILE_NULL │ Object FILE_NULL of type File │
├────────────────────────────┼───────────────────────────────────────┤
│ pickle │ Object pickle of type Pickle │
└────────────────────────────┴───────────────────────────────────────┘
MPI4PY.TYPING
Added in version 4.0.0.
This module provides type aliases used to add type hints to the various functions and methods within the
MPI module.
SEE ALSO:
Module typing
Documentation of the typing standard module.
Types Summary
┌────────────────┬──────────────────────────────────────┐
│ SupportsBuffer │ Python buffer protocol. │
├────────────────┼──────────────────────────────────────┤
│ SupportsDLPack │ DLPack data interchange protocol. │
├────────────────┼──────────────────────────────────────┤
│ SupportsCAI │ CUDA Array Interface (CAI) protocol. │
├────────────────┼──────────────────────────────────────┤
│ Buffer │ Buffer-like object. │
├────────────────┼──────────────────────────────────────┤
│ Bottom │ Start of the address range. │
├────────────────┼──────────────────────────────────────┤
│ InPlace │ In-place buffer argument. │
├────────────────┼──────────────────────────────────────┤
│ Aint │ Address-sized integral type. │
├────────────────┼──────────────────────────────────────┤
│ Count │ Integral type for counts. │
├────────────────┼──────────────────────────────────────┤
│ Displ │ Integral type for displacements. │
├────────────────┼──────────────────────────────────────┤
│ Offset │ Integral type for offsets. │
├────────────────┼──────────────────────────────────────┤
│ TypeSpec │ Datatype specification. │
├────────────────┼──────────────────────────────────────┤
│ BufSpec │ Buffer specification. │
├────────────────┼──────────────────────────────────────┤
│ BufSpecB │ Buffer specification (block). │
├────────────────┼──────────────────────────────────────┤
│ BufSpecV │ Buffer specification (vector). │
├────────────────┼──────────────────────────────────────┤
│ BufSpecW │ Buffer specification (generalized). │
├────────────────┼──────────────────────────────────────┤
│ TargetSpec │ Target specification. │
└────────────────┴──────────────────────────────────────┘
Types Documentation
mpi4py.typing.SupportsBuffer = <class 'mpi4py.typing.SupportsBuffer'>
Python buffer protocol.
SEE ALSO:
Buffer Protocol
mpi4py.typing.SupportsDLPack = <class 'mpi4py.typing.SupportsDLPack'>
DLPack data interchange protocol.
SEE ALSO:
dlpack:python-spec
mpi4py.typing.SupportsCAI = <class 'mpi4py.typing.SupportsCAI'>
CUDA Array Interface (CAI) protocol.
SEE ALSO:
numba:cuda-array-interface
mpi4py.typing.Buffer
Buffer-like object.
alias of SupportsBuffer | SupportsDLPack | SupportsCAI
mpi4py.typing.Bottom
Start of the address range.
alias of BottomType | None
mpi4py.typing.InPlace
In-place buffer argument.
alias of InPlaceType | None
mpi4py.typing.Aint = <class 'numbers.Integral'>
Address-sized integral type.
alias of numbers.Integral
mpi4py.typing.Count = <class 'numbers.Integral'>
Integral type for counts.
alias of numbers.Integral
mpi4py.typing.Displ = <class 'numbers.Integral'>
Integral type for displacements.
alias of numbers.Integral
mpi4py.typing.Offset = <class 'numbers.Integral'>
Integral type for offsets.
alias of numbers.Integral
mpi4py.typing.TypeSpec
Datatype specification.
alias of Datatype | str
mpi4py.typing.BufSpec
Buffer specification.
• Buffer
• Tuple[Buffer, Count]
• Tuple[Buffer, TypeSpec]
• Tuple[Buffer, Count, TypeSpec]
• Tuple[Bottom, Count, Datatype]
alias of SupportsBuffer | SupportsDLPack | SupportsCAI | Tuple[SupportsBuffer | SupportsDLPack |
SupportsCAI, Integral] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Datatype | str] | ‐
Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Integral, Datatype | str] | Tuple[BottomType
| None, Integral, Datatype] | List[Any]
mpi4py.typing.BufSpecB
Buffer specification (block).
• Buffer
• Tuple[Buffer, Count]
• Tuple[Buffer, TypeSpec]
• Tuple[Buffer, Count, TypeSpec]
alias of SupportsBuffer | SupportsDLPack | SupportsCAI | Tuple[SupportsBuffer | SupportsDLPack |
SupportsCAI, Integral] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Datatype | str] | ‐
Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Integral, Datatype | str] | List[Any]
mpi4py.typing.BufSpecV
Buffer specification (vector).
• Buffer
• Tuple[Buffer, Sequence[Count]]
• Tuple[Buffer, Tuple[Sequence[Count], Sequence[Displ]]]
• Tuple[Buffer, TypeSpec]
• Tuple[Buffer, Sequence[Count], TypeSpec]
• Tuple[Buffer, Tuple[Sequence[Count], Sequence[Displ]], TypeSpec]
• Tuple[Buffer, Sequence[Count], Sequence[Displ], TypeSpec]
• Tuple[Bottom, Tuple[Sequence[Count], Sequence[Displ]], Datatype]
• Tuple[Bottom, Sequence[Count], Sequence[Displ], Datatype]
alias of SupportsBuffer | SupportsDLPack | SupportsCAI | Tuple[SupportsBuffer | SupportsDLPack |
SupportsCAI, Sequence[Integral]] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Tuple[‐
Sequence[Integral], Sequence[Integral]]] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI,
Datatype | str] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Sequence[Integral],
Datatype | str] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Tuple[Sequence[Integral], ‐
Sequence[Integral]], Datatype | str] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, ‐
Sequence[Integral], Sequence[Integral], Datatype | str] | Tuple[BottomType | None, Tuple[‐
Sequence[Integral], Sequence[Integral]], Datatype] | Tuple[BottomType | None, Sequence[Integral],
Sequence[Integral], Datatype] | List[Any]
mpi4py.typing.BufSpecW
Buffer specification (generalized).
• Tuple[Buffer, Sequence[Datatype]]
• Tuple[Buffer, Tuple[Sequence[Count], Sequence[Displ]], Sequence[Datatype]]
• Tuple[Buffer, Sequence[Count], Sequence[Displ], Sequence[Datatype]]
• Tuple[Bottom, Tuple[Sequence[Count], Sequence[Displ]], Sequence[Datatype]]
• Tuple[Bottom, Sequence[Count], Sequence[Displ], Sequence[Datatype]]
alias of Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Sequence[Datatype]] | Tuple[‐
SupportsBuffer | SupportsDLPack | SupportsCAI, Tuple[Sequence[Integral], Sequence[Integral]], ‐
Sequence[Datatype]] | Tuple[SupportsBuffer | SupportsDLPack | SupportsCAI, Sequence[Integral], ‐
Sequence[Integral], Sequence[Datatype]] | Tuple[BottomType | None, Tuple[Sequence[Integral], ‐
Sequence[Integral]], Sequence[Datatype]] | Tuple[BottomType | None, Sequence[Integral], Sequence[‐
Integral], Sequence[Datatype]] | List[Any]
mpi4py.typing.TargetSpec
Target specification.
• Displ
• Tuple[()]
• Tuple[Displ]
• Tuple[Displ, Count]
• Tuple[Displ, Count, Datatype]
alias of Integral | Tuple | Tuple[Integral] | Tuple[Integral, Integral] | Tuple[Integral, ‐
Integral, Datatype | str] | List[Any]
mpi4py.typing.S = TypeVar("S")
Invariant TypeVar.
mpi4py.typing.T = TypeVar("T")
Invariant TypeVar.
mpi4py.typing.U = TypeVar("U")
Invariant TypeVar.
mpi4py.typing.V = TypeVar("V")
Invariant TypeVar.
MPI4PY.FUTURES
Added in version 3.0.0.
This package provides a high-level interface for asynchronously executing callables on a pool of worker
processes using MPI for inter-process communication.
The mpi4py.futures package is based on concurrent.futures from the Python standard library. More
precisely, mpi4py.futures provides the MPIPoolExecutor class as a concrete implementation of the abstract
class Executor. The submit() interface schedules a callable to be executed asynchronously and returns a
Future object representing the execution of the callable. Future instances can be queried for the call
result or exception. Sets of Future instances can be passed to the wait() and as_completed() functions.
SEE ALSO:
Module concurrent.futures
Documentation of the concurrent.futures standard module.
MPIPoolExecutor
The MPIPoolExecutor class uses a pool of MPI processes to execute calls asynchronously. By performing
computations in separate processes, it allows to side-step the global interpreter lock but also means
that only picklable objects can be executed and returned. The __main__ module must be importable by
worker processes, thus MPIPoolExecutor instances may not work in the interactive interpreter.
MPIPoolExecutor takes advantage of the dynamic process management features introduced in the MPI-2
standard. In particular, the MPI.Intracomm.Spawn method of MPI.COMM_SELF is used in the master (or
parent) process to spawn new worker (or child) processes running a Python interpreter. The master process
uses a separate thread (one for each MPIPoolExecutor instance) to communicate back and forth with the
workers. The worker processes serve the execution of tasks in the main (and only) thread until they are
signaled for completion.
NOTE:
The worker processes must import the main script in order to unpickle any callable defined in the ‐
__main__ module and submitted from the master process. Furthermore, the callables may need access to
other global variables. At the worker processes, mpi4py.futures executes the main script code (using
the runpy module) under the __worker__ namespace to define the __main__ module. The __main__ and
__worker__ modules are added to sys.modules (both at the master and worker processes) to ensure proper
pickling and unpickling.
WARNING:
During the initial import phase at the workers, the main script cannot create and use new
MPIPoolExecutor instances. Otherwise, each worker would attempt to spawn a new pool of workers,
leading to infinite recursion. mpi4py.futures detects such recursive attempts to spawn new workers and
aborts the MPI execution environment. As the main script code is run under the __worker__ namespace,
the easiest way to avoid spawn recursion is using the idiom if __name__ == '__main__': ... in the main
script.
class mpi4py.futures.MPIPoolExecutor(max_workers=None, initializer=None, initargs=(), **kwargs)
An Executor subclass that executes calls asynchronously using a pool of at most max_workers
processes. If max_workers is None or not given, its value is determined from the
MPI4PY_FUTURES_MAX_WORKERS environment variable if set, or the MPI universe size if set, otherwise
a single worker process is spawned. If max_workers is lower than or equal to 0, then a ValueError
will be raised.
initializer is an optional callable that is called at the start of each worker process before
executing any tasks; initargs is a tuple of arguments passed to the initializer. If initializer
raises an exception, all pending tasks and any attempt to submit new tasks to the pool will raise
a BrokenExecutor exception.
Other parameters:
• python_exe: Path to the Python interpreter executable used to spawn worker processes, otherwise
sys.executable is used.
• python_args: list or iterable with additional command line flags to pass to the Python
executable. Command line flags determined from inspection of sys.flags, sys.warnoptions and ‐
sys._xoptions in are passed unconditionally.
• mpi_info: dict or iterable yielding (key, value) pairs. These (key, value) pairs are passed
(through an MPI.Info object) to the MPI.Intracomm.Spawn call used to spawn worker processes.
This mechanism allows telling the MPI runtime system where and how to start the processes. Check
the documentation of the backend MPI implementation about the set of keys it interprets and the
corresponding format for values.
• globals: dict or iterable yielding (name, value) pairs to initialize the main module namespace
in worker processes.
• main: If set to False, do not import the __main__ module in worker processes. Setting main to ‐
False prevents worker processes from accessing definitions in the parent __main__ namespace.
• path: list or iterable with paths to append to sys.path in worker processes to extend the module
search path.
• wdir: Path to set the current working directory in worker processes using os.chdir(). The
initial working directory is set by the MPI implementation. Quality MPI implementations should
honor a wdir info key passed through mpi_info, although such feature is not mandatory.
• env: dict or iterable yielding (name, value) pairs with environment variables to update ‐
os.environ in worker processes. The initial environment is set by the MPI implementation. MPI
implementations may allow setting the initial environment through mpi_info, however such feature
is not required nor recommended by the MPI standard.
• use_pkl5: If set to True, use pickle5 with out-of-band buffers for interprocess communication.
If use_pkl5 is set to None or not given, its value is determined from the
MPI4PY_FUTURES_USE_PKL5 environment variable. Using pickle5 with out-of-band buffers may benefit
applications dealing with large buffer-like objects like NumPy arrays. See mpi4py.util.pkl5 for
additional information.
• backoff: float value specifying the maximum number of seconds a worker thread or process
suspends execution with time.sleep() while idle-waiting. If not set, its value is determined
from the MPI4PY_FUTURES_BACKOFF environment variable if set, otherwise the default value of
0.001 seconds is used. Lower values will reduce latency and increase execution throughput for
very short-lived tasks, albeit at the expense of spinning CPU cores and increased energy
consumption.
submit(func, *args, **kwargs)
Schedule the callable, func, to be executed as func(*args, **kwargs) and returns a Future
object representing the execution of the callable.
executor = MPIPoolExecutor(max_workers=1)
future = executor.submit(pow, 321, 1234)
print(future.result())
map(func, *iterables, timeout=None, chunksize=1, **kwargs)
Equivalent to map(func, *iterables) except func is executed asynchronously and several
calls to func may be made concurrently, out-of-order, in separate processes. The returned
iterator raises a TimeoutError if __next__() is called and the result isn’t available after
timeout seconds from the original call to map(). timeout can be an int or a float. If
timeout is not specified or None, there is no limit to the wait time. If a call raises an
exception, then that exception will be raised when its value is retrieved from the
iterator. This method chops iterables into a number of chunks which it submits to the pool
as separate tasks. The (approximate) size of these chunks can be specified by setting
chunksize to a positive integer. For very long iterables, using a large value for chunksize
can significantly improve performance compared to the default size of one. By default, the
returned iterator yields results in-order, waiting for successive tasks to complete . This
behavior can be changed by passing the keyword argument unordered as True, then the result
iterator will yield a result as soon as any of the tasks complete.
executor = MPIPoolExecutor(max_workers=3)
for result in executor.map(pow, [2]*32, range(32)):
print(result)
starmap(func, iterable, timeout=None, chunksize=1, **kwargs)
Equivalent to itertools.starmap(func, iterable). Used instead of map() when argument
parameters are already grouped in tuples from a single iterable (the data has been
“pre-zipped”). map(func, *iterable) is equivalent to starmap(func, zip(*iterable)).
executor = MPIPoolExecutor(max_workers=3)
iterable = ((2, n) for n in range(32))
for result in executor.starmap(pow, iterable):
print(result)
shutdown(wait=True, cancel_futures=False)
Signal the executor that it should free any resources that it is using when the currently
pending futures are done executing. Calls to submit() and map() made after shutdown() will
raise RuntimeError.
If wait is True then this method will not return until all the pending futures are done
executing and the resources associated with the executor have been freed. If wait is False
then this method will return immediately and the resources associated with the executor
will be freed when all pending futures are done executing. Regardless of the value of
wait, the entire Python program will not exit until all pending futures are done executing.
If cancel_futures is True, this method will cancel all pending futures that the executor
has not started running. Any futures that are completed or running won’t be cancelled,
regardless of the value of cancel_futures.
You can avoid having to call this method explicitly if you use the with statement, which
will shutdown the executor instance (waiting as if shutdown() were called with wait set to
True).
import time
with MPIPoolExecutor(max_workers=1) as executor:
future = executor.submit(time.sleep, 2)
assert future.done()
bootup(wait=True)
Signal the executor that it should allocate eagerly any required resources (in particular,
MPI worker processes). If wait is True, then bootup() will not return until the executor
resources are ready to process submissions. Resources are automatically allocated in the
first call to submit(), thus calling bootup() explicitly is seldom needed.
num_workers
Number or worker processes in the pool.
MPI4PY_FUTURES_MAX_WORKERS
If the max_workers parameter to MPIPoolExecutor is None or not given, the
MPI4PY_FUTURES_MAX_WORKERS environment variable provides a fallback value for the maximum number
of MPI worker processes to spawn.
Added in version 3.1.0.
MPI4PY_FUTURES_USE_PKL5
If the use_pkl5 keyword argument to MPIPoolExecutor is None or not given, the
MPI4PY_FUTURES_USE_PKL5 environment variable provides a fallback value for whether the executor
should use pickle5 with out-of-band buffers for interprocess communication. Accepted values are 0
and 1 (interpreted as False and True, respectively), and strings specifying a YAML boolean value
(case-insensitive). Using pickle5 with out-of-band buffers may benefit applications dealing with
large buffer-like objects like NumPy arrays. See mpi4py.util.pkl5 for additional information.
Added in version 4.0.0.
MPI4PY_FUTURES_BACKOFF
If the backoff keyword argument to MPIPoolExecutor is not given, the MPI4PY_FUTURES_BACKOFF
environment variable can be set to a float value specifying the maximum number of seconds a worker
thread or process suspends execution with time.sleep() while idle-waiting. If not set, the default
backoff value is 0.001 seconds. Lower values will reduce latency and increase execution throughput
for very short-lived tasks, albeit at the expense of spinning CPU cores and increased energy
consumption.
Added in version 4.0.0.
NOTE:
As the master process uses a separate thread to perform MPI communication with the workers, the
backend MPI implementation should provide support for MPI.THREAD_MULTIPLE. However, some popular MPI
implementations do not support yet concurrent MPI calls from multiple threads. Additionally, users may
decide to initialize MPI with a lower level of thread support. If the level of thread support in the
backend MPI is less than MPI.THREAD_MULTIPLE, mpi4py.futures will use a global lock to serialize MPI
calls. If the level of thread support is less than MPI.THREAD_SERIALIZED, mpi4py.futures will emit a ‐
RuntimeWarning.
WARNING:
If the level of thread support in the backend MPI is less than MPI.THREAD_SERIALIZED (i.e, it is
either MPI.THREAD_SINGLE or MPI.THREAD_FUNNELED), in theory mpi4py.futures cannot be used. Rather than
raising an exception, mpi4py.futures emits a warning and takes a “cross-fingers” attitude to continue
execution in the hope that serializing MPI calls with a global lock will actually work.
MPICommExecutor
Legacy MPI-1 implementations (as well as some vendor MPI-2 implementations) do not support the dynamic
process management features introduced in the MPI-2 standard. Additionally, job schedulers and batch
systems in supercomputing facilities may pose additional complications to applications using the
MPI_Comm_spawn() routine.
With these issues in mind, mpi4py.futures supports an additional, more traditional, SPMD-like usage
pattern requiring MPI-1 calls only. Python applications are started the usual way, e.g., using the
mpiexec command. Python code should make a collective call to the MPICommExecutor context manager to
partition the set of MPI processes within a MPI communicator in one master processes and many workers
processes. The master process gets access to an MPIPoolExecutor instance to submit tasks. Meanwhile, the
worker process follow a different execution path and team-up to execute the tasks submitted from the
master.
Besides alleviating the lack of dynamic process management features in legacy MPI-1 or partial MPI-2
implementations, the MPICommExecutor context manager may be useful in classic MPI-based Python
applications willing to take advantage of the simple, task-based, master/worker approach available in the
mpi4py.futures package.
class mpi4py.futures.MPICommExecutor(comm=None, root=0)
Context manager for MPIPoolExecutor. This context manager splits a MPI (intra)communicator comm
(defaults to MPI.COMM_WORLD if not provided or None) in two disjoint sets: a single master process
(with rank root in comm) and the remaining worker processes. These sets are then connected through
an intercommunicator. The target of the with statement is assigned either an MPIPoolExecutor
instance (at the master) or None (at the workers).
from mpi4py import MPI
from mpi4py.futures import MPICommExecutor
with MPICommExecutor(MPI.COMM_WORLD, root=0) as executor:
if executor is not None:
future = executor.submit(abs, -42)
assert future.result() == 42
answer = set(executor.map(abs, [-42, 42]))
assert answer == {42}
WARNING:
If MPICommExecutor is passed a communicator of size one (e.g., MPI.COMM_SELF), then the executor
instance assigned to the target of the with statement will execute all submitted tasks in a single
worker thread, thus ensuring that task execution still progress asynchronously. However, the GIL will
prevent the main and worker threads from running concurrently in multicore processors. Moreover, the
thread context switching may harm noticeably the performance of CPU-bound tasks. In case of I/O-bound
tasks, the GIL is not usually an issue, however, as a single worker thread is used, it progress one
task at a time. We advice against using MPICommExecutor with communicators of size one and suggest
refactoring your code to use instead a ThreadPoolExecutor.
Command line
Recalling the issues related to the lack of support for dynamic process management features in MPI
implementations, mpi4py.futures supports an alternative usage pattern where Python code (either from
scripts, modules, or zip files) is run under command line control of the mpi4py.futures package by
passing -m mpi4py.futures to the python executable. The mpi4py.futures invocation should be passed a
pyfile path to a script (or a zipfile/directory containing a __main__.py file). Additionally,
mpi4py.futures accepts -m mod to execute a module named mod, -c cmd to execute a command string cmd, or
even - to read commands from standard input (sys.stdin). Summarizing, mpi4py.futures can be invoked in
the following ways:
• $ mpiexec -n numprocs python -m mpi4py.futures pyfile [arg] ...
• $ mpiexec -n numprocs python -m mpi4py.futures -m mod [arg] ...
• $ mpiexec -n numprocs python -m mpi4py.futures -c cmd [arg] ...
• $ mpiexec -n numprocs python -m mpi4py.futures - [arg] ...
Before starting the main script execution, mpi4py.futures splits MPI.COMM_WORLD in one master (the
process with rank 0 in MPI.COMM_WORLD) and numprocs - 1 workers and connects them through an MPI
intercommunicator. Afterwards, the master process proceeds with the execution of the user script code,
which eventually creates MPIPoolExecutor instances to submit tasks. Meanwhile, the worker processes
follow a different execution path to serve the master. Upon successful termination of the main script at
the master, the entire MPI execution environment exists gracefully. In case of any unhandled exception in
the main script, the master process calls MPI.COMM_WORLD.Abort(1) to prevent deadlocks and force
termination of entire MPI execution environment.
WARNING:
Running scripts under command line control of mpi4py.futures is quite similar to executing a
single-process application that spawn additional workers as required. However, there is a very
important difference users should be aware of. All MPIPoolExecutor instances created at the master
will share the pool of workers. Tasks submitted at the master from many different executors will be
scheduled for execution in random order as soon as a worker is idle. Any executor can easily starve
all the workers (e.g., by calling MPIPoolExecutor.map() with long iterables). If that ever happens,
submissions from other executors will not be serviced until free workers are available.
SEE ALSO:
Command line
Documentation on Python command line interface.
Parallel tasks
The mpi4py.futures package favors an embarrassingly parallel execution model involving a series of
sequential tasks independent of each other and executed asynchronously. Albeit unnatural, MPIPoolExecutor
can still be used for handling workloads involving parallel tasks, where worker processes communicate and
coordinate each other via MPI.
mpi4py.futures.get_comm_workers()
Access an intracommunicator grouping MPI worker processes.
Executing parallel tasks with mpi4py.futures requires following some rules, cf. highlighted lines in
example cpi.py :
• Use MPIPoolExecutor.num_workers to determine the number of worker processes in the executor and submit
exactly one callable per worker process using the MPIPoolExecutor.submit() method.
• The submitted callable must use get_comm_workers() to access an intracommunicator grouping MPI worker
processes. Afterwards, it is highly recommended calling the Barrier() method on the communicator. The
barrier synchronization ensures that every worker process is executing the submitted callable exactly
once. Afterwards, the parallel task can safely perform any kind of point-to-point or collective
operation using the returned communicator.
• The Future instances returned by MPIPoolExecutor.submit() should be collected in a sequence. Use ‐
wait() with the sequence of Future instances to ensure logical completion of the parallel task.
Utilities
The mpi4py.futures package provides additional utilities for handling Future instances.
mpi4py.futures.collect(fs)
Gather a collection of futures in a new future.
Parameters
fs – Collection of futures.
Returns
New future producing as result a list with results from fs.
mpi4py.futures.compose(future, resulthook=None, excepthook=None)
Compose the completion of a future with result and exception handlers.
Parameters
• future – Input future instance.
• resulthook – Function to be called once the input future completes with success. Once the
input future finish running with success, its result value is the input argument for
resulthook. The result of resulthook is set as the result of the output future. If
resulthook is None, the output future is completed directly with the result of the input
future.
• excepthook – Function to be called once the input future completes with failure. Once the
input future finish running with failure, its exception value is the input argument for
excepthook. If excepthook returns an Exception instance, it is set as the exception of
the output future. Otherwise, the result of excepthook is set as the result of the
output future. If excepthook is None, the output future is set as failed with the
exception from the input future.
Returns
Output future instance to be completed once the input future is completed and either
resulthook or excepthook finish executing.
Examples
Computing the Julia set
The following julia.py script computes the Julia set and dumps an image to disk in binary PGM format. The
code starts by importing MPIPoolExecutor from the mpi4py.futures package. Next, some global constants and
functions implement the computation of the Julia set. The computations are protected with the standard if
__name__ == '__main__': ... idiom. The image is computed by whole scanlines submitting all these tasks
at once using the map method. The result iterator yields scanlines in-order as the tasks complete.
Finally, each scanline is dumped to disk.
julia.py
from mpi4py.futures import MPIPoolExecutor
x0, x1, w = -2.0, +2.0, 640*2
y0, y1, h = -1.5, +1.5, 480*2
dx = (x1 - x0) / w
dy = (y1 - y0) / h
c = complex(0, 0.65)
def julia(x, y):
z = complex(x, y)
n = 255
while abs(z) < 3 and n > 1:
z = z**2 + c
n -= 1
return n
def julia_line(k):
line = bytearray(w)
y = y1 - k * dy
for j in range(w):
x = x0 + j * dx
line[j] = julia(x, y)
return line
if __name__ == '__main__':
with MPIPoolExecutor() as executor:
image = executor.map(julia_line, range(h))
with open('julia.pgm', 'wb') as f:
f.write(b'P5 %d %d %d\n' % (w, h, 255))
for line in image:
f.write(line)
The recommended way to execute the script is by using the mpiexec command specifying one MPI process
(master) and (optional but recommended) the desired MPI universe size, which determines the number of
additional dynamically spawned processes (workers). The MPI universe size is provided either by a batch
system or set by the user via command-line arguments to mpiexec or environment variables. Below we
provide examples for MPICH and Open MPI implementations [1]. In all of these examples, the mpiexec
command launches a single master process running the Python interpreter and executing the main script.
When required, mpi4py.futures spawns the pool of 16 worker processes. The master submits tasks to the
workers and waits for the results. The workers receive incoming tasks, execute them, and send back the
results to the master.
When using MPICH implementation or its derivatives based on the Hydra process manager, users can set the
MPI universe size via the -usize argument to mpiexec:
$ mpiexec -n 1 -usize 17 python julia.py
or, alternatively, by setting the MPIEXEC_UNIVERSE_SIZE environment variable:
$ env MPIEXEC_UNIVERSE_SIZE=17 mpiexec -n 1 python julia.py
In the Open MPI implementation, the MPI universe size can be set via the -host argument to mpiexec:
$ mpiexec -n 1 -host localhost:17 python julia.py
Another way to specify the number of workers is to use the mpi4py.futures-specific environment variable
MPI4PY_FUTURES_MAX_WORKERS:
$ env MPI4PY_FUTURES_MAX_WORKERS=16 mpiexec -n 1 python julia.py
Note that in this case, the MPI universe size is ignored.
Alternatively, users may decide to execute the script in a more traditional way, that is, all the MPI
processes are started at once. The user script is run under command-line control of mpi4py.futures
passing the -m flag to the python executable:
$ mpiexec -n 17 python -m mpi4py.futures julia.py
As explained previously, the 17 processes are partitioned in one master and 16 workers. The master
process executes the main script while the workers execute the tasks submitted by the master.
[1] When using an MPI implementation other than MPICH or Open MPI, please check the documentation of the
implementation and/or batch system for the ways to specify the desired MPI universe size.
Computing Pi (parallel task)
The number \pi can be approximated via numerical integration with the simple midpoint rule, that is:
\pi = \int_{0}^{1} \frac{4}{1+x^2} \,dx \approx
\frac{1}{n} \sum_{i=1}^{n} \frac{4}{1 + \left[\frac{1}{n} \left(i-\frac{1}{2}\right) \right]^2} .
The following cpi.py script computes such approximations using mpi4py.futures with a parallel task
involving a collective reduction operation. Highlighted lines correspond to the rules discussed in
Parallel tasks.
cpi.py
import math
import sys
from mpi4py.futures import MPIPoolExecutor, wait
from mpi4py.futures import get_comm_workers
def compute_pi(n):
# Access intracommunicator and synchronize
comm = get_comm_workers()
comm.Barrier()
rank = comm.Get_rank()
size = comm.Get_size()
# Local computation
h = 1.0 / n
s = 0.0
for i in range(rank + 1, n + 1, size):
x = h * (i - 0.5)
s += 4.0 / (1.0 + x**2)
pi_partial = s * h
# Parallel reduce-to-all
pi = comm.allreduce(pi_partial)
# All workers return the same value
return pi
if __name__ == '__main__':
n = int(sys.argv[1]) if len(sys.argv) > 1 else 256
with MPIPoolExecutor() as executor:
# Submit exactly one callable per worker
P = executor.num_workers
fs = [executor.submit(compute_pi, n) for _ in range(P)]
# Wait for all workers to finish
wait(fs)
# Get result from the first future object.
# In this particular example, due to using reduce-to-all,
# all the other future objects hold the same result value.
pi = fs[0].result()
print(
f"pi: {pi:.16f}, error: {abs(pi - math.pi):.3e}",
f"({n:d} intervals, {P:d} workers)",
)
To run in modern MPI-2 mode:
$ env MPI4PY_FUTURES_MAX_WORKERS=4 mpiexec -n 1 python cpi.py 128
pi: 3.1415977398528137, error: 5.086e-06 (128 intervals, 4 workers)
$ env MPI4PY_FUTURES_MAX_WORKERS=8 mpiexec -n 1 python cpi.py 512
pi: 3.1415929714812316, error: 3.179e-07 (512 intervals, 8 workers)
To run in legacy MPI-1 mode:
$ mpiexec -n 5 python -m mpi4py.futures cpi.py 128
pi: 3.1415977398528137, error: 5.086e-06 (128 intervals, 4 workers)
$ mpiexec -n 9 python -m mpi4py.futures cpi.py 512
pi: 3.1415929714812316, error: 3.179e-07 (512 intervals, 8 workers)
Citation
If mpi4py.futures been significant to a project that leads to an academic publication, please acknowledge
our work by citing the following article [mpi4py-futures]:
[mpi4py-futures]
M. Rogowski, S. Aseeri, D. Keyes, and L. Dalcin, mpi4py.futures: MPI-Based Asynchronous Task
Execution for Python, IEEE Transactions on Parallel and Distributed Systems, 34(2):611-622, 2023. ‐
https://doi.org/10.1109/TPDS.2022.3225481
MPI4PY.UTIL
Added in version 3.1.0.
The mpi4py.util package collects miscellaneous utilities within the intersection of Python and MPI.
mpi4py.util.dtlib
Added in version 3.1.0.
The mpi4py.util.dtlib module provides converter routines between NumPy and MPI datatypes.
mpi4py.util.dtlib.from_numpy_dtype(dtype)
Convert NumPy datatype to MPI datatype.
Parameters
dtype (DTypeLike) – NumPy dtype-like object.
Return type
Datatype
mpi4py.util.dtlib.to_numpy_dtype(datatype)
Convert MPI datatype to NumPy datatype.
Parameters
datatype (Datatype) – MPI datatype.
Return type
dtype[Any]
mpi4py.util.pkl5
Added in version 3.1.0.
pickle protocol 5 (see PEP 574) introduced support for out-of-band buffers, allowing for more efficient
handling of certain object types with large memory footprints.
MPI for Python uses the traditional in-band handling of buffers. This approach is appropriate for
communicating non-buffer Python objects, or buffer-like objects with small memory footprints. For
point-to-point communication, in-band buffer handling allows for the communication of a pickled stream
with a single MPI message, at the expense of additional CPU and memory overhead in the pickling and
unpickling steps.
The mpi4py.util.pkl5 module provides communicator wrapper classes reimplementing pickle-based
point-to-point and collective communication methods using pickle protocol 5. Handling out-of-band buffers
necessarily involves multiple MPI messages, thus increasing latency and hurting performance in case of
small size data. However, in case of large size data, the zero-copy savings of out-of-band buffer
handling more than offset the extra latency costs. Additionally, these wrapper methods overcome the
infamous 2 GiB message count limit (MPI-1 to MPI-3).
NOTE:
Support for pickle protocol 5 is available in the pickle module within the Python standard library
since Python 3.8. Previous Python 3 releases can use the pickle5 backport, which is available on PyPI
and can be installed with:
python -m pip install pickle5
class mpi4py.util.pkl5.Request
Request.
Custom request class for nonblocking communications.
NOTE:
Request is not a subclass of mpi4py.MPI.Request
Free() Free a communication request.
Return type
None
free() Free a communication request.
Return type
None
cancel()
Cancel a communication request.
Return type
None
get_status(status=None)
Non-destructive test for the completion of a request.
Parameters
status (Status | None)
Return type
bool
test(status=None)
Test for the completion of a request.
Parameters
status (Status | None)
Return type
tuple[bool, Any | None]
wait(status=None)
Wait for a request to complete.
Parameters
status (Status | None)
Return type
Any
classmethod get_status_all(requests, statuses=None)
Non-destructive test for the completion of all requests.
Classmethod
classmethod testall(requests, statuses=None)
Test for the completion of all requests.
Classmethod
classmethod waitall(requests, statuses=None)
Wait for all requests to complete.
Classmethod
class mpi4py.util.pkl5.Message
Message.
Custom message class for matching probes.
NOTE:
Message is not a subclass of mpi4py.MPI.Message
free() Do nothing.
Return type
None
recv(status=None)
Blocking receive of matched message.
Parameters
status (Status | None)
Return type
Any
irecv()
Nonblocking receive of matched message.
Return type
Request
classmethod probe(comm, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a matched message.
Classmethod
classmethod iprobe(comm, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a matched message.
Classmethod
class mpi4py.util.pkl5.Comm
Communicator.
Base communicator wrapper class.
send(obj, dest, tag=0)
Blocking send in standard mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
None
bsend(obj, dest, tag=0)
Blocking send in buffered mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
None
ssend(obj, dest, tag=0)
Blocking send in synchronous mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
None
isend(obj, dest, tag=0)
Nonblocking send in standard mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
Request
ibsend(obj, dest, tag=0)
Nonblocking send in buffered mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
Request
issend(obj, dest, tag=0)
Nonblocking send in synchronous mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
Request
recv(buf=None, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking receive.
Parameters
• buf (Buffer | None)
• source (int)
• tag (int)
• status (Status | None)
Return type
Any
irecv(buf=None, source=ANY_SOURCE, tag=ANY_TAG)
Nonblocking receive.
WARNING:
This method cannot be supported reliably and raises RuntimeError.
Parameters
• buf (Buffer | None)
• source (int)
• tag (int)
Return type
Request
sendrecv(sendobj, dest, sendtag=0, recvbuf=None, source=ANY_SOURCE, recvtag=ANY_TAG, status=None)
Send and receive.
Parameters
• sendobj (Any)
• dest (int)
• sendtag (int)
• recvbuf (Buffer | None)
• source (int)
• recvtag (int)
• status (Status | None)
Return type
Any
mprobe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a matched message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Message
improbe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a matched message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Message | None
bcast(obj, root=0)
Broadcast.
Added in version 3.1.0.
Parameters
• obj (Any)
• root (int)
Return type
Any
gather(sendobj, root=0)
Gather.
Added in version 4.0.0.
Parameters
• sendobj (Any)
• root (int)
Return type
list[Any] | None
scatter(sendobj, root=0)
Scatter.
Added in version 4.0.0.
Parameters
• sendobj (Sequence[Any] | None)
• root (int)
Return type
Any
allgather(sendobj)
Gather to All.
Added in version 4.0.0.
Parameters
sendobj (Any)
Return type
list[Any]
alltoall(sendobj)
All to All Scatter/Gather.
Added in version 4.0.0.
Parameters
sendobj (Sequence[Any])
Return type
list[Any]
class mpi4py.util.pkl5.Intracomm
Intracommunicator.
Intracommunicator wrapper class.
class mpi4py.util.pkl5.Intercomm
Intercommunicator.
Intercommunicator wrapper class.
Examples
test-pkl5-1.py
import numpy as np
from mpi4py import MPI
from mpi4py.util import pkl5
comm = pkl5.Intracomm(MPI.COMM_WORLD) # comm wrapper
size = comm.Get_size()
rank = comm.Get_rank()
dst = (rank + 1) % size
src = (rank - 1) % size
sobj = np.full(1024**3, rank, dtype='i4') # > 4 GiB
sreq = comm.isend(sobj, dst, tag=42)
robj = comm.recv (None, src, tag=42)
sreq.Free()
assert np.min(robj) == src
assert np.max(robj) == src
test-pkl5-2.py
import numpy as np
from mpi4py import MPI
from mpi4py.util import pkl5
comm = pkl5.Intracomm(MPI.COMM_WORLD) # comm wrapper
size = comm.Get_size()
rank = comm.Get_rank()
dst = (rank + 1) % size
src = (rank - 1) % size
sobj = np.full(1024**3, rank, dtype='i4') # > 4 GiB
sreq = comm.isend(sobj, dst, tag=42)
status = MPI.Status()
rmsg = comm.mprobe(status=status)
assert status.Get_source() == src
assert status.Get_tag() == 42
rreq = rmsg.irecv()
robj = rreq.wait()
sreq.Free()
assert np.max(robj) == src
assert np.min(robj) == src
mpi4py.util.pool
Added in version 4.0.0.
SEE ALSO:
This module intends to be a drop-in replacement for the multiprocessing.pool interface from the Python
standard library. The Pool class exposed here is implemented as a thin wrapper around
MPIPoolExecutor.
NOTE:
The mpi4py.futures package offers a higher level interface for asynchronously pushing tasks to MPI
worker process, allowing for a clear separation between submitting tasks and waiting for the results.
class mpi4py.util.pool.Pool
Pool using MPI processes as workers.
__init__(processes=None, initializer=None, initargs=(), **kwargs)
Initialize a new Pool instance.
Parameters
• processes (int | None) – Number of worker processes.
• initializer (Callable[[...], object] | None) – An callable used to initialize
workers processes.
• initargs (Iterable[Any]) – A tuple of arguments to pass to the initializer.
• kwargs (Any)
Return type
None
NOTE:
Additional keyword arguments are passed down to the MPIPoolExecutor constructor.
WARNING:
The maxtasksperchild and context arguments of multiprocessing.pool.Pool are not
supported. Specifying maxtasksperchild or context with a value other than None will
issue a warning of category UserWarning.
apply(func, args=(), kwds={})
Call func with arguments args and keyword arguments kwds.
Equivalent to func(*args, **kwds).
Parameters
• func (Callable[[...], T])
• args (Iterable[Any])
• kwds (Mapping[str, Any])
Return type
T
apply_async(func, args=(), kwds={}, callback=None, error_callback=None)
Asynchronous version of apply() returning ApplyResult.
Parameters
• func (Callable[..., T])
• args (Iterable[Any])
• kwds (Mapping[str, Any])
• callback (Callable[[T], object] | None)
• error_callback (Callable[[BaseException], object] | None)
Return type
AsyncResult[T]
map(func, iterable, chunksize=None)
Apply func to each element in iterable.
Equivalent to list(map(func, iterable)).
Block until all results are ready and return them in a list.
The iterable is choped into a number of chunks which are submitted as separate tasks. The
(approximate) size of these chunks can be specified by setting chunksize to a positive
integer.
Consider using imap() or imap_unordered() with explicit chunksize for better efficiency.
Parameters
• func (Callable[[S], T])
• iterable (Iterable[S])
• chunksize (int | None)
Return type
list[T]
map_async(func, iterable, chunksize=None, callback=None, error_callback=None)
Asynchronous version of map() returning MapResult.
Parameters
• func (Callable[[S], T])
• iterable (Iterable[S])
• chunksize (int | None)
• callback (Callable[[T], None] | None)
• error_callback (Callable[[BaseException], None] | None)
Return type
MapResult[T]
imap(func, iterable, chunksize=1)
Like map() but return an iterator.
Equivalent to map(func, iterable).
Parameters
• func (Callable[[S], T])
• iterable (Iterable[S])
• chunksize (int)
Return type
Iterator[T]
imap_unordered(func, iterable, chunksize=1)
Like imap() but ordering of results is arbitrary.
Parameters
• func (Callable[[S], T])
• iterable (Iterable[S])
• chunksize (int)
Return type
Iterator[T]
starmap(func, iterable, chunksize=None)
Apply func to each argument tuple in iterable.
Equivalent to list(itertools.starmap(func, iterable)).
Block until all results are ready and return them in a list.
The iterable is choped into a number of chunks which are submitted as separate tasks. The
(approximate) size of these chunks can be specified by setting chunksize to a positive
integer.
Consider using istarmap() or istarmap_unordered() with explicit chunksize for better
efficiency.
Parameters
• func (Callable[[...], T])
• iterable (Iterable[Iterable[Any]])
• chunksize (int | None)
Return type
list[T]
starmap_async(func, iterable, chunksize=None, callback=None, error_callback=None)
Asynchronous version of starmap() returning MapResult.
Parameters
• func (Callable[..., T])
• iterable (Iterable[Iterable[Any]])
• chunksize (int | None)
• callback (Callable[[T], None] | None)
• error_callback (Callable[[BaseException], None] | None)
Return type
MapResult[T]
istarmap(func, iterable, chunksize=1)
Like starmap() but return an iterator.
Equivalent to itertools.starmap(func, iterable).
Parameters
• func (Callable[[...], T])
• iterable (Iterable[Iterable[Any]])
• chunksize (int)
Return type
Iterator[T]
istarmap_unordered(func, iterable, chunksize=1)
Like istarmap() but ordering of results is arbitrary.
Parameters
• func (Callable[[...], T])
• iterable (Iterable[Iterable[Any]])
• chunksize (int)
Return type
Iterator[T]
close()
Prevent any more tasks from being submitted to the pool.
Return type
None
terminate()
Stop the worker processes without completing pending tasks.
Return type
None
join() Wait for the worker processes to exit.
Return type
None
class mpi4py.util.pool.ThreadPool
Bases: Pool
Pool using threads as workers.
class mpi4py.util.pool.AsyncResult
Asynchronous result.
get(timeout=None)
Return the result when it arrives.
If timeout is not None and the result does not arrive within timeout seconds then raise ‐
TimeoutError.
If the remote call raised an exception then that exception will be reraised.
Parameters
timeout (float | None)
Return type
T
wait(timeout=None)
Wait until the result is available or timeout seconds pass.
Parameters
timeout (float | None)
Return type
None
ready()
Return whether the call has completed.
Return type
bool
successful()
Return whether the call completed without raising an exception.
If the result is not ready then raise ValueError.
Return type
bool
class mpi4py.util.pool.ApplyResult
Bases: AsyncResult
Result type of apply_async().
class mpi4py.util.pool.MapResult
Bases: AsyncResult
Result type of map_async() and starmap_async().
mpi4py.util.sync
Added in version 4.0.0.
The mpi4py.util.sync module provides parallel synchronization utilities.
Sequential execution
class mpi4py.util.sync.Sequential
Sequential execution.
Context manager for sequential execution within a group of MPI processes.
The implementation is based in MPI-1 point-to-point communication. A process with rank i waits in
a blocking receive until the previous process rank i-1 finish executing and signals the next rank
i with a send.
__init__(comm, tag=0)
Initialize sequential execution.
Parameters
• comm (Intracomm) – Intracommunicator context.
• tag (int) – Tag for point-to-point communication.
Return type
None
__enter__()
Enter sequential execution.
Return type
Self
__exit__(*exc)
Exit sequential execution.
Parameters
exc (object)
Return type
None
begin()
Begin sequential execution.
Return type
None
end() End sequential execution.
Return type
None
Global counter
class mpi4py.util.sync.Counter
Global counter.
Produce consecutive values within a group of MPI processes. The counter interface is close to that
of itertools.count.
The implementation is based in MPI-3 one-sided operations. A root process (typically rank 0) holds
the counter, and its value is queried and incremented with an atomic RMA fetch-and-add operation.
__init__(start=0, step=1, *, typecode='i', comm=COMM_SELF, info=INFO_NULL, root=0)
Initialize global counter.
Parameters
• start (int) – Start value.
• step (int) – Increment value.
• typecode (str) – Type code as defined in the array module.
• comm (Intracomm) – Intracommunicator context.
• info (Info) – Info object for RMA context creation.
• root (int) – Process rank holding the counter memory.
Return type
None
__iter__()
Implement iter(self).
Return type
Self
__next__()
Implement next(self).
Return type
int
next(incr=None)
Return current value and increment.
Parameters
incr (int | None) – Increment value.
Returns
The counter value before incrementing.
Return type
int
free() Free counter resources.
Return type
None
Mutual exclusion
class mpi4py.util.sync.Mutex
Mutual exclusion.
Establish a critical section or mutual exclusion among MPI processes.
The mutex interface is close to that of threading.Lock and threading.RLock, allowing the use of
either recursive or non-recursive mutual exclusion. However, a mutex should be used within a group
of MPI processes, not threads.
In non-recursive mode, the semantics of Mutex are somewhat different than these of threading.Lock:
• Once acquired, a mutex is held and owned by a process until released.
• Trying to acquire a mutex already held raises RuntimeError.
• Trying to release a mutex not yet held raises RuntimeError.
This mutex implementation uses the scalable and fair spinlock algorithm from [mcs-paper] and took
inspiration from the MPI-3 RMA implementation of [uam-book].
__init__(*, recursive=False, comm=COMM_SELF, info=INFO_NULL)
Initialize mutex object.
Parameters
• comm (Intracomm) – Intracommunicator context.
• recursive (bool) – Whether to allow recursive acquisition.
• info (Info) – Info object for RMA context creation.
Return type
None
__enter__()
Acquire mutex.
Return type
Self
__exit__(*exc)
Release mutex.
Parameters
exc (object)
Return type
None
acquire(blocking=True)
Acquire mutex, blocking or non-blocking.
Parameters
blocking (bool) – If True, block until the mutex is held.
Returns
True if the mutex is held, False otherwise.
Return type
bool
release()
Release mutex.
Return type
None
locked()
Return whether the mutex is held.
Return type
bool
count()
Return the recursion count.
Return type
int
free() Free mutex resources.
Return type
None
[mcs-paper]
John M. Mellor-Crummey and Michael L. Scott. Algorithms for scalable synchronization on
shared-memory multiprocessors. ACM Transactions on Computer Systems, 9(1):21-65, February 1991. ‐
https://doi.org/10.1145/103727.103729
[uam-book]
William Gropp, Torsten Hoefler, Rajeev Thakur, Ewing Lusk. Using Advanced MPI - Modern Features of
the Message-Passing Interface. Chapter 4, Section 4.7, Pages 130-131. The MIT Press, November 2014.
https://mitpress.mit.edu/9780262527637/using-advanced-mpi/
Condition variable
class mpi4py.util.sync.Condition
Condition variable.
A condition variable allows one or more MPI processes to wait until they are notified by another
processes.
The condition variable interface is close to that of threading.Condition, allowing the use of
either recursive or non-recursive mutual exclusion. However, the condition variable should be
used within a group of MPI processes, not threads.
This condition variable implementation uses a MPI-3 RMA-based scalable and fair circular queue
algorithm to track the set of waiting processes.
__init__(mutex=None, *, recursive=True, comm=COMM_SELF, info=INFO_NULL)
Initialize condition variable.
Parameters
• mutex (Mutex | None) – Mutual exclusion object.
• recursive (bool) – Whether to allow recursive acquisition.
• comm (Intracomm) – Intracommunicator context.
• info (Info) – Info object for RMA context creation.
Return type
None
__enter__()
Acquire the underlying mutex.
Return type
Self
__exit__(*exc)
Release the underlying mutex.
Parameters
exc (object)
Return type
None
acquire(blocking=True)
Acquire the underlying mutex.
Parameters
blocking (bool)
Return type
bool
release()
Release the underlying mutex.
Return type
None
locked()
Return whether the underlying mutex is held.
Return type
bool
wait() Wait until notified by another process.
Returns
Always True.
Return type
Literal[True]
wait_for(predicate)
Wait until a predicate evaluates to True.
Parameters
predicate (Callable[[], T]) – callable returning a boolean.
Returns
The result of predicate once it evaluates to True.
Return type
T
notify(n=1)
Wake up one or more processes waiting on this condition.
Parameters
n (int) – Maximum number of processes to wake up.
Returns
The actual number of processes woken up.
Return type
int
notify_all()
Wake up all processes waiting on this condition.
Returns
The actual number of processes woken up.
Return type
int
free() Free condition resources.
Return type
None
Semaphore object
class mpi4py.util.sync.Semaphore
Semaphore object.
A semaphore object manages an internal counter which is decremented by each acquire() call and
incremented by each release() call. The internal counter never reaches a value below zero; when
acquire() finds that it is zero, it blocks and waits until some other process calls release().
The semaphore interface is close to that of threading.Semaphore and threading.BoundedSemaphore,
allowing the use of either bounded (default) or unbounded semaphores. With a bounded semaphore,
the internal counter never exceeds its initial value; otherwise release() raises ValueError.
This semaphore implementation uses a global Counter and a Condition variable to handle waiting and
and notification.
__init__(value=1, *, bounded=True, comm=COMM_SELF, info=INFO_NULL)
Initialize semaphore object.
Parameters
• value (int) – Initial value for internal counter.
• bounded (bool) – Bound internal counter to initial value.
• comm (Intracomm) – Intracommunicator context.
• info (Info) – Info object for RMA context creation.
Return type
None
__enter__()
Acquire semaphore.
Return type
Self
__exit__(*exc)
Release semaphore.
Parameters
exc (object)
Return type
None
acquire(blocking=True)
Acquire semaphore, decrementing the internal counter by one.
Parameters
blocking (bool) – If True, block until the semaphore is acquired.
Returns
True if the semaphore is acquired, False otherwise.
Return type
bool
release(n=1)
Release semaphore, incrementing the internal counter by one or more.
Parameters
n (int) – Increment for the internal counter.
Return type
None
free() Free semaphore resources.
Return type
None
Examples
test-sync-1.py
from mpi4py import MPI
from mpi4py.util.sync import Counter, Sequential
comm = MPI.COMM_WORLD
counter = Counter(comm)
with Sequential(comm):
value = next(counter)
counter.free()
assert comm.rank == value
test-sync-2.py
from mpi4py import MPI
from mpi4py.util.sync import Counter, Mutex
comm = MPI.COMM_WORLD
mutex = Mutex(comm)
counter = Counter(comm)
with mutex:
value = next(counter)
counter.free()
mutex.free()
assert (
list(range(comm.size)) ==
sorted(comm.allgather(value))
)
MPI4PY.RUN
Added in version 3.0.0.
At import time, mpi4py initializes the MPI execution environment calling MPI_Init_thread() and installs
an exit hook to automatically call MPI_Finalize() just before the Python process terminates.
Additionally, mpi4py overrides the default ERRORS_ARE_FATAL error handler in favor of ERRORS_RETURN,
which allows translating MPI errors in Python exceptions. These departures from standard MPI behavior may
be controversial, but are quite convenient within the highly dynamic Python programming environment.
Third-party code using mpi4py can just from mpi4py import MPI and perform MPI calls without the tedious
initialization/finalization handling. MPI errors, once translated automatically to Python exceptions,
can be dealt with the common try…except…finally clauses; unhandled MPI exceptions will print a traceback
which helps in locating problems in source code.
Unfortunately, the interplay of automatic MPI finalization and unhandled exceptions may lead to
deadlocks. In unattended runs, these deadlocks will drain the battery of your laptop, or burn precious
allocation hours in your supercomputing facility.
Exceptions and deadlocks
Consider the following snippet of Python code. Assume this code is stored in a standard Python script
file and run with mpiexec in two or more processes.
deadlock.py
from mpi4py import MPI
assert MPI.COMM_WORLD.Get_size() > 1
rank = MPI.COMM_WORLD.Get_rank()
if rank == 0:
1/0
MPI.COMM_WORLD.send(None, dest=1, tag=42)
elif rank == 1:
MPI.COMM_WORLD.recv(source=0, tag=42)
Process 0 raises ZeroDivisionError exception before performing a send call to process 1. As the exception
is not handled, the Python interpreter running in process 0 will proceed to exit with non-zero status.
However, as mpi4py installed a finalizer hook to call MPI_Finalize() before exit, process 0 will block
waiting for other processes to also enter the MPI_Finalize() call. Meanwhile, process 1 will block
waiting for a message to arrive from process 0, thus never reaching to MPI_Finalize(). The whole MPI
execution environment is irremediably in a deadlock state.
To alleviate this issue, mpi4py offers a simple, alternative command line execution mechanism based on
using the -m flag and implemented with the runpy module. To use this features, Python code should be run
passing -m mpi4py in the command line invoking the Python interpreter. In case of unhandled exceptions,
the finalizer hook will call MPI_Abort() on the MPI_COMM_WORLD communicator, thus effectively aborting
the MPI execution environment.
WARNING:
When a process is forced to abort, resources (e.g. open files) are not cleaned-up and any registered
finalizers (either with the atexit module, the Python C/API function Py_AtExit(), or even the C
standard library function atexit()) will not be executed. Thus, aborting execution is an extremely
impolite way of ensuring process termination. However, MPI provides no other mechanism to recover from
a deadlock state.
Command line
The use of -m mpi4py to execute Python code on the command line resembles that of the Python interpreter.
• mpiexec -n numprocs python -m mpi4py pyfile [arg] ...
• mpiexec -n numprocs python -m mpi4py -m mod [arg] ...
• mpiexec -n numprocs python -m mpi4py -c cmd [arg] ...
• mpiexec -n numprocs python -m mpi4py - [arg] ...
<pyfile>
Execute the Python code contained in pyfile, which must be a filesystem path referring to either a
Python file, a directory containing a __main__.py file, or a zipfile containing a __main__.py
file.
-m <mod>
Search sys.path for the named module mod and execute its contents.
-c <cmd>
Execute the Python code in the cmd string command.
- Read commands from standard input (sys.stdin).
SEE ALSO:
Command line
Documentation on Python command line interface.
MPI4PY.BENCH
Added in version 3.0.0.
REFERENCE
┌────────────┬────────────────────────────┐
│ mpi4py.MPI │ Message Passing Interface. │
└────────────┴────────────────────────────┘
mpi4py.MPI
Message Passing Interface.
Classes
┌─────────────────────┬───────────────────────────────────────┐
│ BottomType │ Type of BOTTOM. │
├─────────────────────┼───────────────────────────────────────┤
│ BufferAutomaticType │ Type of BUFFER_AUTOMATIC. │
├─────────────────────┼───────────────────────────────────────┤
│ Cartcomm │ Cartesian topology intracommunicator. │
├─────────────────────┼───────────────────────────────────────┤
│ Comm │ Communication context. │
├─────────────────────┼───────────────────────────────────────┤
│ Datatype │ Datatype object. │
├─────────────────────┼───────────────────────────────────────┤
│ Distgraphcomm │ Distributed graph topology │
│ │ intracommunicator. │
├─────────────────────┼───────────────────────────────────────┤
│ Errhandler │ Error handler. │
├─────────────────────┼───────────────────────────────────────┤
│ File │ File I/O context. │
├─────────────────────┼───────────────────────────────────────┤
│ Graphcomm │ General graph topology │
│ │ intracommunicator. │
├─────────────────────┼───────────────────────────────────────┤
│ Grequest │ Generalized request handler. │
├─────────────────────┼───────────────────────────────────────┤
│ Group │ Group of processes. │
├─────────────────────┼───────────────────────────────────────┤
│ InPlaceType │ Type of IN_PLACE. │
├─────────────────────┼───────────────────────────────────────┤
│ Info │ Info object. │
├─────────────────────┼───────────────────────────────────────┤
│ Intercomm │ Intercommunicator. │
├─────────────────────┼───────────────────────────────────────┤
│ Intracomm │ Intracommunicator. │
├─────────────────────┼───────────────────────────────────────┤
│ Message │ Matched message. │
├─────────────────────┼───────────────────────────────────────┤
│ Op │ Reduction operation. │
├─────────────────────┼───────────────────────────────────────┤
│ Pickle │ Pickle/unpickle Python objects. │
├─────────────────────┼───────────────────────────────────────┤
│ Prequest │ Persistent request handler. │
├─────────────────────┼───────────────────────────────────────┤
│ Request │ Request handler. │
├─────────────────────┼───────────────────────────────────────┤
│ Session │ Session context. │
├─────────────────────┼───────────────────────────────────────┤
│ Status │ Status object. │
├─────────────────────┼───────────────────────────────────────┤
│ Topocomm │ Topology intracommunicator. │
├─────────────────────┼───────────────────────────────────────┤
│ Win │ Remote memory access context. │
├─────────────────────┼───────────────────────────────────────┤
│ buffer │ Buffer. │
├─────────────────────┼───────────────────────────────────────┤
│ memory │ alias of buffer │
└─────────────────────┴───────────────────────────────────────┘
mpi4py.MPI.BottomType
class mpi4py.MPI.BottomType
Bases: int
Type of BOTTOM.
static __new__(cls)
Return type
Self
mpi4py.MPI.BufferAutomaticType
class mpi4py.MPI.BufferAutomaticType
Bases: int
Type of BUFFER_AUTOMATIC.
static __new__(cls)
Return type
Self
mpi4py.MPI.Cartcomm
class mpi4py.MPI.Cartcomm
Bases: Topocomm
Cartesian topology intracommunicator.
static __new__(cls, comm=None)
Parameters
comm (Cartcomm | None)
Return type
Self
Methods Summary
┌────────────────────────┬───────────────────────────────────────┐
│ Get_cart_rank(coords) │ Translate logical coordinates to │
│ │ ranks. │
├────────────────────────┼───────────────────────────────────────┤
│ Get_coords(rank) │ Translate ranks to logical │
│ │ coordinates. │
├────────────────────────┼───────────────────────────────────────┤
│ Get_dim() │ Return number of dimensions. │
├────────────────────────┼───────────────────────────────────────┤
│ Get_topo() │ Return information on the cartesian │
│ │ topology. │
├────────────────────────┼───────────────────────────────────────┤
│ Shift(direction, disp) │ Return a process ranks for data │
│ │ shifting with Sendrecv. │
├────────────────────────┼───────────────────────────────────────┤
│ Sub(remain_dims) │ Return a lower-dimensional Cartesian │
│ │ topology. │
└────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌─────────┬───────────────────────┐
│ coords │ Coordinates. │
├─────────┼───────────────────────┤
│ dim │ Number of dimensions. │
├─────────┼───────────────────────┤
│ dims │ Dimensions. │
├─────────┼───────────────────────┤
│ ndim │ Number of dimensions. │
├─────────┼───────────────────────┤
│ periods │ Periodicity. │
├─────────┼───────────────────────┤
│ topo │ Topology information. │
└─────────┴───────────────────────┘
Methods Documentation
Get_cart_rank(coords)
Translate logical coordinates to ranks.
Parameters
coords (Sequence[int])
Return type
int
Get_coords(rank)
Translate ranks to logical coordinates.
Parameters
rank (int)
Return type
list[int]
Get_dim()
Return number of dimensions.
Return type
int
Get_topo()
Return information on the cartesian topology.
Return type
tuple[list[int], list[int], list[int]]
Shift(direction, disp)
Return a process ranks for data shifting with Sendrecv.
Parameters
• direction (int)
• disp (int)
Return type
tuple[int, int]
Sub(remain_dims)
Return a lower-dimensional Cartesian topology.
Parameters
remain_dims (Sequence[bool])
Return type
Cartcomm
Attributes Documentation
coords Coordinates.
dim Number of dimensions.
dims Dimensions.
ndim Number of dimensions.
periods
Periodicity.
topo Topology information.
mpi4py.MPI.Comm
class mpi4py.MPI.Comm
Bases: object
Communication context.
static __new__(cls, comm=None)
Parameters
comm (Comm | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Abort([errorcode]) │ Terminate the MPI execution │
│ │ environment. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ack_failed([num_to_ack]) │ Acknowledge failures on a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Agree(flag) │ Blocking agreement. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allgather(sendbuf, recvbuf) │ Gather to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allgather_init(sendbuf, recvbuf[, │ Persistent Gather to All. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allgatherv(sendbuf, recvbuf) │ Gather to All Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allgatherv_init(sendbuf, recvbuf[, │ Persistent Gather to All Vector. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allreduce(sendbuf, recvbuf[, op]) │ Reduce to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allreduce_init(sendbuf, recvbuf[, op, │ Persistent Reduce to All. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alltoall(sendbuf, recvbuf) │ All to All Scatter/Gather. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alltoall_init(sendbuf, recvbuf[, │ Persistent All to All Scatter/Gather. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alltoallv(sendbuf, recvbuf) │ All to All Scatter/Gather Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alltoallv_init(sendbuf, recvbuf[, │ Persistent All to All Scatter/Gather │
│ info]) │ Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alltoallw(sendbuf, recvbuf) │ All to All Scatter/Gather General. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alltoallw_init(sendbuf, recvbuf[, │ Persistent All to All Scatter/Gather │
│ info]) │ General. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Attach_buffer(buf) │ Attach a user-provided buffer for │
│ │ sending in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Barrier() │ Barrier synchronization. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Barrier_init([info]) │ Persistent Barrier. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Bcast(buf[, root]) │ Broadcast data from one process to │
│ │ all other processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Bcast_init(buf[, root, info]) │ Persistent Broadcast. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Bsend(buf, dest[, tag]) │ Blocking send in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Bsend_init(buf, dest[, tag]) │ Persistent request for a send in │
│ │ buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Call_errhandler(errorcode) │ Call the error handler installed on a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Clone() │ Clone an existing communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Compare(comm) │ Compare two communicators. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create(group) │ Create communicator from group. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_errhandler(errhandler_fn) │ Create a new error handler for │
│ │ communicators. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_keyval([copy_fn, delete_fn, │ Create a new attribute key for │
│ nopython]) │ communicators. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Delete_attr(keyval) │ Delete attribute value associated │
│ │ with a key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Detach_buffer() │ Remove an existing attached buffer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Disconnect() │ Disconnect from a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Dup([info]) │ Duplicate a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Dup_with_info(info) │ Duplicate a communicator with hints. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush_buffer() │ Block until all buffered messages │
│ │ have been transmitted. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free() │ Free a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free_keyval(keyval) │ Free an attribute key for │
│ │ communicators. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Gather(sendbuf, recvbuf[, root]) │ Gather data to one process from all │
│ │ other processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Gather_init(sendbuf, recvbuf[, root, │ Persistent Gather. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Gatherv(sendbuf, recvbuf[, root]) │ Gather Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Gatherv_init(sendbuf, recvbuf[, root, │ Persistent Gather Vector. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_attr(keyval) │ Retrieve attribute value by key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_errhandler() │ Get the error handler for a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_failed() │ Extract the group of failed │
│ │ processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_group() │ Access the group associated with a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_info() │ Return the current hints for a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_name() │ Get the print name for this │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_parent() │ Return the parent intercommunicator │
│ │ for this process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_rank() │ Return the rank of this process in a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_size() │ Return the number of processes in a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_topology() │ Return the type of topology (if any) │
│ │ associated with a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iagree(flag) │ Nonblocking agreement. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iallgather(sendbuf, recvbuf) │ Nonblocking Gather to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iallgatherv(sendbuf, recvbuf) │ Nonblocking Gather to All Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iallreduce(sendbuf, recvbuf[, op]) │ Nonblocking Reduce to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ialltoall(sendbuf, recvbuf) │ Nonblocking All to All │
│ │ Scatter/Gather. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ialltoallv(sendbuf, recvbuf) │ Nonblocking All to All Scatter/Gather │
│ │ Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ialltoallw(sendbuf, recvbuf) │ Nonblocking All to All Scatter/Gather │
│ │ General. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ibarrier() │ Nonblocking Barrier. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ibcast(buf[, root]) │ Nonblocking Broadcast. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ibsend(buf, dest[, tag]) │ Nonblocking send in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Idup([info]) │ Nonblocking duplicate a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Idup_with_info(info) │ Nonblocking duplicate a communicator │
│ │ with hints. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iflush_buffer() │ Nonblocking flush for buffered │
│ │ messages. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Igather(sendbuf, recvbuf[, root]) │ Nonblocking Gather. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Igatherv(sendbuf, recvbuf[, root]) │ Nonblocking Gather Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Improbe([source, tag, status]) │ Nonblocking test for a matched │
│ │ message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iprobe([source, tag, status]) │ Nonblocking test for a message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Irecv(buf[, source, tag]) │ Nonblocking receive. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ireduce(sendbuf, recvbuf[, op, root]) │ Nonblocking Reduce to Root. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ireduce_scatter(sendbuf, recvbuf[, │ Nonblocking Reduce-Scatter (vector │
│ ...]) │ version). │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ireduce_scatter_block(sendbuf, │ Nonblocking Reduce-Scatter Block │
│ recvbuf[, op]) │ (regular, non-vector version). │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Irsend(buf, dest[, tag]) │ Nonblocking send in ready mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Is_inter() │ Return whether the communicator is an │
│ │ intercommunicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Is_intra() │ Return whether the communicator is an │
│ │ intracommunicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Is_revoked() │ Indicate whether the communicator has │
│ │ been revoked. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iscatter(sendbuf, recvbuf[, root]) │ Nonblocking Scatter. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iscatterv(sendbuf, recvbuf[, root]) │ Nonblocking Scatter Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Isend(buf, dest[, tag]) │ Nonblocking send. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Isendrecv(sendbuf, dest[, sendtag, │ Nonblocking send and receive. │
│ recvbuf, ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Isendrecv_replace(buf, dest[, │ Send and receive a message. │
│ sendtag, ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ishrink() │ Nonblocking shrink a communicator to │
│ │ remove all failed processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Issend(buf, dest[, tag]) │ Nonblocking send in synchronous mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Join(fd) │ Interconnect two processes connected │
│ │ by a socket. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Mprobe([source, tag, status]) │ Blocking test for a matched message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Precv_init(buf, partitions[, source, │ Create request for a partitioned recv │
│ tag, info]) │ operation. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Probe([source, tag, status]) │ Blocking test for a message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Psend_init(buf, partitions, dest[, │ Create request for a partitioned send │
│ tag, info]) │ operation. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Recv(buf[, source, tag, status]) │ Blocking receive. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Recv_init(buf[, source, tag]) │ Create a persistent request for a │
│ │ receive. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Reduce(sendbuf, recvbuf[, op, root]) │ Reduce to Root. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Reduce_init(sendbuf, recvbuf[, op, │ Persistent Reduce to Root. │
│ root, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Reduce_scatter(sendbuf, recvbuf[, │ Reduce-Scatter (vector version). │
│ ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Reduce_scatter_block(sendbuf, │ Reduce-Scatter Block (regular, │
│ recvbuf[, op]) │ non-vector version). │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Reduce_scatter_block_init(sendbuf, │ Persistent Reduce-Scatter Block │
│ recvbuf) │ (regular, non-vector version). │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Reduce_scatter_init(sendbuf, │ Persistent Reduce-Scatter (vector │
│ recvbuf[, ...]) │ version). │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Revoke() │ Revoke a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Rsend(buf, dest[, tag]) │ Blocking send in ready mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Rsend_init(buf, dest[, tag]) │ Persistent request for a send in │
│ │ ready mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Scatter(sendbuf, recvbuf[, root]) │ Scatter data from one process to all │
│ │ other processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Scatter_init(sendbuf, recvbuf[, root, │ Persistent Scatter. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Scatterv(sendbuf, recvbuf[, root]) │ Scatter Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Scatterv_init(sendbuf, recvbuf[, │ Persistent Scatter Vector. │
│ root, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Send(buf, dest[, tag]) │ Blocking send. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Send_init(buf, dest[, tag]) │ Create a persistent request for a │
│ │ standard send. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Sendrecv(sendbuf, dest[, sendtag, │ Send and receive a message. │
│ recvbuf, ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Sendrecv_replace(buf, dest[, sendtag, │ Send and receive a message. │
│ ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_attr(keyval, attrval) │ Store attribute value associated with │
│ │ a key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_errhandler(errhandler) │ Set the error handler for a │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_info(info) │ Set new values for the hints │
│ │ associated with a communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_name(name) │ Set the print name for this │
│ │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Shrink() │ Shrink a communicator to remove all │
│ │ failed processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Split([color, key]) │ Split communicator by color and key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Split_type(split_type[, key, info]) │ Split communicator by split type. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ssend(buf, dest[, tag]) │ Blocking send in synchronous mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ssend_init(buf, dest[, tag]) │ Persistent request for a send in │
│ │ synchronous mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ allgather(sendobj) │ Gather to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ allreduce(sendobj[, op]) │ Reduce to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ alltoall(sendobj) │ All to All Scatter/Gather. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ barrier() │ Barrier synchronization. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ bcast(obj[, root]) │ Broadcast. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ bsend(obj, dest[, tag]) │ Send in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null or predefined. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ gather(sendobj[, root]) │ Gather. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ ibsend(obj, dest[, tag]) │ Nonblocking send in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ improbe([source, tag, status]) │ Nonblocking test for a matched │
│ │ message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ iprobe([source, tag, status]) │ Nonblocking test for a message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ irecv([buf, source, tag]) │ Nonblocking receive. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ isend(obj, dest[, tag]) │ Nonblocking send. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ issend(obj, dest[, tag]) │ Nonblocking send in synchronous mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ mprobe([source, tag, status]) │ Blocking test for a matched message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ probe([source, tag, status]) │ Blocking test for a message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ recv([buf, source, tag, status]) │ Receive. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ reduce(sendobj[, op, root]) │ Reduce to Root. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ scatter(sendobj[, root]) │ Scatter. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ send(obj, dest[, tag]) │ Send in standard mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ sendrecv(sendobj, dest[, sendtag, │ Send and Receive. │
│ recvbuf, ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ ssend(obj, dest[, tag]) │ Send in synchronous mode. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌──────────┬───────────────────────┐
│ group │ Group. │
├──────────┼───────────────────────┤
│ handle │ MPI handle. │
├──────────┼───────────────────────┤
│ info │ Info hints. │
├──────────┼───────────────────────┤
│ is_inter │ Is intercommunicator. │
├──────────┼───────────────────────┤
│ is_intra │ Is intracommunicator. │
├──────────┼───────────────────────┤
│ is_topo │ Is a topology. │
├──────────┼───────────────────────┤
│ name │ Print name. │
├──────────┼───────────────────────┤
│ rank │ Rank of this process. │
├──────────┼───────────────────────┤
│ size │ Number of processes. │
├──────────┼───────────────────────┤
│ topology │ Topology type. │
└──────────┴───────────────────────┘
Methods Documentation
Abort(errorcode=0)
Terminate the MPI execution environment.
WARNING:
The invocation of this method prevents the execution of various Python exit and cleanup
mechanisms. Use this method as a last resort to prevent parallel deadlocks in case of
unrecoverable errors.
Parameters
errorcode (int)
Return type
NoReturn
Ack_failed(num_to_ack=None)
Acknowledge failures on a communicator.
Parameters
num_to_ack (int | None)
Return type
int
Agree(flag)
Blocking agreement.
Parameters
flag (int)
Return type
int
Allgather(sendbuf, recvbuf)
Gather to All.
Gather data from all processes and broadcast the combined data to all other processes.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecB)
Return type
None
Allgather_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Gather to All.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecB)
• info (Info)
Return type
Prequest
Allgatherv(sendbuf, recvbuf)
Gather to All Vector.
Gather data from all processes and send it to all other processes providing different
amounts of data and displacements.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecV)
Return type
None
Allgatherv_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Gather to All Vector.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecV)
• info (Info)
Return type
Prequest
Allreduce(sendbuf, recvbuf, op=SUM)
Reduce to All.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
Return type
None
Allreduce_init(sendbuf, recvbuf, op=SUM, info=INFO_NULL)
Persistent Reduce to All.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
• info (Info)
Return type
Prequest
Alltoall(sendbuf, recvbuf)
All to All Scatter/Gather.
Send data to all processes and recv data from all processes.
Parameters
• sendbuf (BufSpecB | InPlace)
• recvbuf (BufSpecB)
Return type
None
Alltoall_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent All to All Scatter/Gather.
Parameters
• sendbuf (BufSpecB | InPlace)
• recvbuf (BufSpecB)
• info (Info)
Return type
Prequest
Alltoallv(sendbuf, recvbuf)
All to All Scatter/Gather Vector.
Send data to all processes and recv data from all processes providing different amounts of
data and displacements.
Parameters
• sendbuf (BufSpecV | InPlace)
• recvbuf (BufSpecV)
Return type
None
Alltoallv_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent All to All Scatter/Gather Vector.
Parameters
• sendbuf (BufSpecV | InPlace)
• recvbuf (BufSpecV)
• info (Info)
Return type
Prequest
Alltoallw(sendbuf, recvbuf)
All to All Scatter/Gather General.
Send/recv data to/from all processes allowing the specification of different counts,
displacements, and datatypes for each dest/source.
Parameters
• sendbuf (BufSpecW | InPlace)
• recvbuf (BufSpecW)
Return type
None
Alltoallw_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent All to All Scatter/Gather General.
Parameters
• sendbuf (BufSpecW | InPlace)
• recvbuf (BufSpecW)
• info (Info)
Return type
Prequest
Attach_buffer(buf)
Attach a user-provided buffer for sending in buffered mode.
Parameters
buf (Buffer | None)
Return type
None
Barrier()
Barrier synchronization.
Return type
None
Barrier_init(info=INFO_NULL)
Persistent Barrier.
Parameters
info (Info)
Return type
Prequest
Bcast(buf, root=0)
Broadcast data from one process to all other processes.
Parameters
• buf (BufSpec)
• root (int)
Return type
None
Bcast_init(buf, root=0, info=INFO_NULL)
Persistent Broadcast.
Parameters
• buf (BufSpec)
• root (int)
• info (Info)
Return type
Prequest
Bsend(buf, dest, tag=0)
Blocking send in buffered mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
None
Bsend_init(buf, dest, tag=0)
Persistent request for a send in buffered mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
Call_errhandler(errorcode)
Call the error handler installed on a communicator.
Parameters
errorcode (int)
Return type
None
Clone()
Clone an existing communicator.
Return type
Self
Compare(comm)
Compare two communicators.
Parameters
comm (Comm)
Return type
int
Create(group)
Create communicator from group.
Parameters
group (Group)
Return type
Comm
classmethod Create_errhandler(errhandler_fn)
Create a new error handler for communicators.
Parameters
errhandler_fn (Callable[[Comm, int], None])
Return type
Errhandler
classmethod Create_keyval(copy_fn=None, delete_fn=None, nopython=False)
Create a new attribute key for communicators.
Parameters
• copy_fn (Callable[[Comm, int, Any], Any] | None)
• delete_fn (Callable[[Comm, int, Any], None] | None)
• nopython (bool)
Return type
int
Delete_attr(keyval)
Delete attribute value associated with a key.
Parameters
keyval (int)
Return type
None
Detach_buffer()
Remove an existing attached buffer.
Return type
Buffer | None
Disconnect()
Disconnect from a communicator.
Return type
None
Dup(info=None)
Duplicate a communicator.
Parameters
info (Info | None)
Return type
Self
Dup_with_info(info)
Duplicate a communicator with hints.
Parameters
info (Info)
Return type
Self
Flush_buffer()
Block until all buffered messages have been transmitted.
Return type
None
Free() Free a communicator.
Return type
None
classmethod Free_keyval(keyval)
Free an attribute key for communicators.
Parameters
keyval (int)
Return type
int
Gather(sendbuf, recvbuf, root=0)
Gather data to one process from all other processes.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecB | None)
• root (int)
Return type
None
Gather_init(sendbuf, recvbuf, root=0, info=INFO_NULL)
Persistent Gather.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecB | None)
• root (int)
• info (Info)
Return type
Prequest
Gatherv(sendbuf, recvbuf, root=0)
Gather Vector.
Gather data to one process from all other processes providing different amounts of data and
displacements.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecV | None)
• root (int)
Return type
None
Gatherv_init(sendbuf, recvbuf, root=0, info=INFO_NULL)
Persistent Gather Vector.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecV | None)
• root (int)
• info (Info)
Return type
Prequest
Get_attr(keyval)
Retrieve attribute value by key.
Parameters
keyval (int)
Return type
int | Any | None
Get_errhandler()
Get the error handler for a communicator.
Return type
Errhandler
Get_failed()
Extract the group of failed processes.
Return type
Group
Get_group()
Access the group associated with a communicator.
Return type
Group
Get_info()
Return the current hints for a communicator.
Return type
Info
Get_name()
Get the print name for this communicator.
Return type
str
classmethod Get_parent()
Return the parent intercommunicator for this process.
Return type
Intercomm
Get_rank()
Return the rank of this process in a communicator.
Return type
int
Get_size()
Return the number of processes in a communicator.
Return type
int
Get_topology()
Return the type of topology (if any) associated with a communicator.
Return type
int
Iagree(flag)
Nonblocking agreement.
Parameters
flag (Buffer)
Return type
Request
Iallgather(sendbuf, recvbuf)
Nonblocking Gather to All.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecB)
Return type
Request
Iallgatherv(sendbuf, recvbuf)
Nonblocking Gather to All Vector.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecV)
Return type
Request
Iallreduce(sendbuf, recvbuf, op=SUM)
Nonblocking Reduce to All.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
Return type
Request
Ialltoall(sendbuf, recvbuf)
Nonblocking All to All Scatter/Gather.
Parameters
• sendbuf (BufSpecB | InPlace)
• recvbuf (BufSpecB)
Return type
Request
Ialltoallv(sendbuf, recvbuf)
Nonblocking All to All Scatter/Gather Vector.
Parameters
• sendbuf (BufSpecV | InPlace)
• recvbuf (BufSpecV)
Return type
Request
Ialltoallw(sendbuf, recvbuf)
Nonblocking All to All Scatter/Gather General.
Parameters
• sendbuf (BufSpecW | InPlace)
• recvbuf (BufSpecW)
Return type
Request
Ibarrier()
Nonblocking Barrier.
Return type
Request
Ibcast(buf, root=0)
Nonblocking Broadcast.
Parameters
• buf (BufSpec)
• root (int)
Return type
Request
Ibsend(buf, dest, tag=0)
Nonblocking send in buffered mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
Idup(info=None)
Nonblocking duplicate a communicator.
Parameters
info (Info | None)
Return type
tuple[Self, Request]
Idup_with_info(info)
Nonblocking duplicate a communicator with hints.
Parameters
info (Info)
Return type
tuple[Self, Request]
Iflush_buffer()
Nonblocking flush for buffered messages.
Return type
Request
Igather(sendbuf, recvbuf, root=0)
Nonblocking Gather.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecB | None)
• root (int)
Return type
Request
Igatherv(sendbuf, recvbuf, root=0)
Nonblocking Gather Vector.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpecV | None)
• root (int)
Return type
Request
Improbe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a matched message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Message | None
Iprobe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
bool
Irecv(buf, source=ANY_SOURCE, tag=ANY_TAG)
Nonblocking receive.
Parameters
• buf (BufSpec)
• source (int)
• tag (int)
Return type
Request
Ireduce(sendbuf, recvbuf, op=SUM, root=0)
Nonblocking Reduce to Root.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec | None)
• op (Op)
• root (int)
Return type
Request
Ireduce_scatter(sendbuf, recvbuf, recvcounts=None, op=SUM)
Nonblocking Reduce-Scatter (vector version).
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• recvcounts (Sequence[int] | None)
• op (Op)
Return type
Request
Ireduce_scatter_block(sendbuf, recvbuf, op=SUM)
Nonblocking Reduce-Scatter Block (regular, non-vector version).
Parameters
• sendbuf (BufSpecB | InPlace)
• recvbuf (BufSpec | BufSpecB)
• op (Op)
Return type
Request
Irsend(buf, dest, tag=0)
Nonblocking send in ready mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
Is_inter()
Return whether the communicator is an intercommunicator.
Return type
bool
Is_intra()
Return whether the communicator is an intracommunicator.
Return type
bool
Is_revoked()
Indicate whether the communicator has been revoked.
Return type
bool
Iscatter(sendbuf, recvbuf, root=0)
Nonblocking Scatter.
Parameters
• sendbuf (BufSpecB | None)
• recvbuf (BufSpec | InPlace)
• root (int)
Return type
Request
Iscatterv(sendbuf, recvbuf, root=0)
Nonblocking Scatter Vector.
Parameters
• sendbuf (BufSpecV | None)
• recvbuf (BufSpec | InPlace)
• root (int)
Return type
Request
Isend(buf, dest, tag=0)
Nonblocking send.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
Isendrecv(sendbuf, dest, sendtag=0, recvbuf=None, source=ANY_SOURCE, recvtag=ANY_TAG)
Nonblocking send and receive.
Parameters
• sendbuf (BufSpec)
• dest (int)
• sendtag (int)
• recvbuf (BufSpec | None)
• source (int)
• recvtag (int)
Return type
Request
Isendrecv_replace(buf, dest, sendtag=0, source=ANY_SOURCE, recvtag=ANY_TAG)
Send and receive a message.
NOTE:
This function is guaranteed not to deadlock in situations where pairs of blocking sends
and receives may deadlock.
CAUTION:
A common mistake when using this function is to mismatch the tags with the source and
destination ranks, which can result in deadlock.
Parameters
• buf (BufSpec)
• dest (int)
• sendtag (int)
• source (int)
• recvtag (int)
Return type
Request
Ishrink()
Nonblocking shrink a communicator to remove all failed processes.
Return type
tuple[Comm, Request]
Issend(buf, dest, tag=0)
Nonblocking send in synchronous mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
classmethod Join(fd)
Interconnect two processes connected by a socket.
Parameters
fd (int)
Return type
Intercomm
Mprobe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a matched message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Message
Precv_init(buf, partitions, source=ANY_SOURCE, tag=ANY_TAG, info=INFO_NULL)
Create request for a partitioned recv operation.
Parameters
• buf (BufSpec)
• partitions (int)
• source (int)
• tag (int)
• info (Info)
Return type
Prequest
Probe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a message.
NOTE:
This function blocks until the message arrives.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Literal[True]
Psend_init(buf, partitions, dest, tag=0, info=INFO_NULL)
Create request for a partitioned send operation.
Parameters
• buf (BufSpec)
• partitions (int)
• dest (int)
• tag (int)
• info (Info)
Return type
Prequest
Recv(buf, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking receive.
NOTE:
This function blocks until the message is received.
Parameters
• buf (BufSpec)
• source (int)
• tag (int)
• status (Status | None)
Return type
None
Recv_init(buf, source=ANY_SOURCE, tag=ANY_TAG)
Create a persistent request for a receive.
Parameters
• buf (BufSpec)
• source (int)
• tag (int)
Return type
Prequest
Reduce(sendbuf, recvbuf, op=SUM, root=0)
Reduce to Root.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec | None)
• op (Op)
• root (int)
Return type
None
Reduce_init(sendbuf, recvbuf, op=SUM, root=0, info=INFO_NULL)
Persistent Reduce to Root.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec | None)
• op (Op)
• root (int)
• info (Info)
Return type
Prequest
Reduce_scatter(sendbuf, recvbuf, recvcounts=None, op=SUM)
Reduce-Scatter (vector version).
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• recvcounts (Sequence[int] | None)
• op (Op)
Return type
None
Reduce_scatter_block(sendbuf, recvbuf, op=SUM)
Reduce-Scatter Block (regular, non-vector version).
Parameters
• sendbuf (BufSpecB | InPlace)
• recvbuf (BufSpec | BufSpecB)
• op (Op)
Return type
None
Reduce_scatter_block_init(sendbuf, recvbuf, op=SUM, info=INFO_NULL)
Persistent Reduce-Scatter Block (regular, non-vector version).
Parameters
• sendbuf (BufSpecB | InPlace)
• recvbuf (BufSpec | BufSpecB)
• op (Op)
• info (Info)
Return type
Prequest
Reduce_scatter_init(sendbuf, recvbuf, recvcounts=None, op=SUM, info=INFO_NULL)
Persistent Reduce-Scatter (vector version).
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• recvcounts (Sequence[int] | None)
• op (Op)
• info (Info)
Return type
Prequest
Revoke()
Revoke a communicator.
Return type
None
Rsend(buf, dest, tag=0)
Blocking send in ready mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
None
Rsend_init(buf, dest, tag=0)
Persistent request for a send in ready mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
Scatter(sendbuf, recvbuf, root=0)
Scatter data from one process to all other processes.
Parameters
• sendbuf (BufSpecB | None)
• recvbuf (BufSpec | InPlace)
• root (int)
Return type
None
Scatter_init(sendbuf, recvbuf, root=0, info=INFO_NULL)
Persistent Scatter.
Parameters
• sendbuf (BufSpecB | None)
• recvbuf (BufSpec | InPlace)
• root (int)
• info (Info)
Return type
Prequest
Scatterv(sendbuf, recvbuf, root=0)
Scatter Vector.
Scatter data from one process to all other processes providing different amounts of data
and displacements.
Parameters
• sendbuf (BufSpecV | None)
• recvbuf (BufSpec | InPlace)
• root (int)
Return type
None
Scatterv_init(sendbuf, recvbuf, root=0, info=INFO_NULL)
Persistent Scatter Vector.
Parameters
• sendbuf (BufSpecV | None)
• recvbuf (BufSpec | InPlace)
• root (int)
• info (Info)
Return type
Prequest
Send(buf, dest, tag=0)
Blocking send.
NOTE:
This function may block until the message is received. Whether Send blocks or not
depends on several factors and is implementation dependent.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
None
Send_init(buf, dest, tag=0)
Create a persistent request for a standard send.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Prequest
Sendrecv(sendbuf, dest, sendtag=0, recvbuf=None, source=ANY_SOURCE, recvtag=ANY_TAG, status=None)
Send and receive a message.
NOTE:
This function is guaranteed not to deadlock in situations where pairs of blocking sends
and receives may deadlock.
CAUTION:
A common mistake when using this function is to mismatch the tags with the source and
destination ranks, which can result in deadlock.
Parameters
• sendbuf (BufSpec)
• dest (int)
• sendtag (int)
• recvbuf (BufSpec | None)
• source (int)
• recvtag (int)
• status (Status | None)
Return type
None
Sendrecv_replace(buf, dest, sendtag=0, source=ANY_SOURCE, recvtag=ANY_TAG, status=None)
Send and receive a message.
NOTE:
This function is guaranteed not to deadlock in situations where pairs of blocking sends
and receives may deadlock.
CAUTION:
A common mistake when using this function is to mismatch the tags with the source and
destination ranks, which can result in deadlock.
Parameters
• buf (BufSpec)
• dest (int)
• sendtag (int)
• source (int)
• recvtag (int)
• status (Status | None)
Return type
None
Set_attr(keyval, attrval)
Store attribute value associated with a key.
Parameters
• keyval (int)
• attrval (Any)
Return type
None
Set_errhandler(errhandler)
Set the error handler for a communicator.
Parameters
errhandler (Errhandler)
Return type
None
Set_info(info)
Set new values for the hints associated with a communicator.
Parameters
info (Info)
Return type
None
Set_name(name)
Set the print name for this communicator.
Parameters
name (str)
Return type
None
Shrink()
Shrink a communicator to remove all failed processes.
Return type
Comm
Split(color=0, key=0)
Split communicator by color and key.
Parameters
• color (int)
• key (int)
Return type
Comm
Split_type(split_type, key=0, info=INFO_NULL)
Split communicator by split type.
Parameters
• split_type (int)
• key (int)
• info (Info)
Return type
Comm
Ssend(buf, dest, tag=0)
Blocking send in synchronous mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
None
Ssend_init(buf, dest, tag=0)
Persistent request for a send in synchronous mode.
Parameters
• buf (BufSpec)
• dest (int)
• tag (int)
Return type
Request
allgather(sendobj)
Gather to All.
Parameters
sendobj (Any)
Return type
list[Any]
allreduce(sendobj, op=SUM)
Reduce to All.
Parameters
• sendobj (Any)
• op (Op | Callable[[Any, Any], Any])
Return type
Any
alltoall(sendobj)
All to All Scatter/Gather.
Parameters
sendobj (Sequence[Any])
Return type
list[Any]
barrier()
Barrier synchronization.
NOTE:
This method is equivalent to Barrier.
Return type
None
bcast(obj, root=0)
Broadcast.
Parameters
• obj (Any)
• root (int)
Return type
Any
bsend(obj, dest, tag=0)
Send in buffered mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
Comm
free() Call Free if not null or predefined.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Comm
gather(sendobj, root=0)
Gather.
Parameters
• sendobj (Any)
• root (int)
Return type
list[Any] | None
ibsend(obj, dest, tag=0)
Nonblocking send in buffered mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
Request
improbe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a matched message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Message | None
iprobe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
bool
irecv(buf=None, source=ANY_SOURCE, tag=ANY_TAG)
Nonblocking receive.
Parameters
• buf (Buffer | None)
• source (int)
• tag (int)
Return type
Request
isend(obj, dest, tag=0)
Nonblocking send.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
Request
issend(obj, dest, tag=0)
Nonblocking send in synchronous mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
Request
mprobe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a matched message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Message
probe(source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a message.
Parameters
• source (int)
• tag (int)
• status (Status | None)
Return type
Literal[True]
py2f()
Return type
int
recv(buf=None, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Receive.
Parameters
• buf (Buffer | None)
• source (int)
• tag (int)
• status (Status | None)
Return type
Any
reduce(sendobj, op=SUM, root=0)
Reduce to Root.
Parameters
• sendobj (Any)
• op (Op | Callable[[Any, Any], Any])
• root (int)
Return type
Any | None
scatter(sendobj, root=0)
Scatter.
Parameters
• sendobj (Sequence[Any] | None)
• root (int)
Return type
Any
send(obj, dest, tag=0)
Send in standard mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
None
sendrecv(sendobj, dest, sendtag=0, recvbuf=None, source=ANY_SOURCE, recvtag=ANY_TAG, status=None)
Send and Receive.
Parameters
• sendobj (Any)
• dest (int)
• sendtag (int)
• recvbuf (Buffer | None)
• source (int)
• recvtag (int)
• status (Status | None)
Return type
Any
ssend(obj, dest, tag=0)
Send in synchronous mode.
Parameters
• obj (Any)
• dest (int)
• tag (int)
Return type
None
Attributes Documentation
group Group.
handle MPI handle.
info Info hints.
is_inter
Is intercommunicator.
is_intra
Is intracommunicator.
is_topo
Is a topology.
name Print name.
rank Rank of this process.
size Number of processes.
topology
Topology type.
mpi4py.MPI.Datatype
class mpi4py.MPI.Datatype
Bases: object
Datatype object.
static __new__(cls, datatype=None)
Parameters
datatype (Datatype | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Commit() │ Commit the datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_contiguous(count) │ Create a contiguous datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_darray(size, rank, gsizes, │ Create a datatype for a distributed │
│ distribs, ...) │ array on Cartesian process grids. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_f90_complex(p, r) │ Return a bounded complex datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_f90_integer(r) │ Return a bounded integer datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_f90_real(p, r) │ Return a bounded real datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_hindexed(blocklengths, │ Create an indexed datatype. │
│ displacements) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_hindexed_block(blocklength, │ Create an indexed datatype with │
│ displacements) │ constant-sized blocks. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_hvector(count, blocklength, │ Create a vector (strided) datatype │
│ stride) │ with stride in bytes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_indexed(blocklengths, │ Create an indexed datatype. │
│ displacements) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_indexed_block(blocklength, │ Create an indexed datatype with │
│ displacements) │ constant-sized blocks. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_keyval([copy_fn, delete_fn, │ Create a new attribute key for │
│ nopython]) │ datatypes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_resized(lb, extent) │ Create a datatype with a new lower │
│ │ bound and extent. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_struct(blocklengths, │ Create a general composite (struct) │
│ displacements, ...) │ datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_subarray(sizes, subsizes, │ Create a datatype for a subarray of a │
│ starts[, order]) │ multidimensional array. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_vector(count, blocklength, │ Create a vector (strided) datatype. │
│ stride) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Delete_attr(keyval) │ Delete attribute value associated │
│ │ with a key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Dup() │ Duplicate a datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free() │ Free the datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free_keyval(keyval) │ Free an attribute key for datatypes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_attr(keyval) │ Retrieve attribute value by key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_contents() │ Return the input arguments used to │
│ │ create a datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_envelope() │ Return the number of input arguments │
│ │ used to create a datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_extent() │ Return lower bound and extent of │
│ │ datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_name() │ Get the print name for this datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_size() │ Return the number of bytes occupied │
│ │ by entries in the datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_true_extent() │ Return the true lower bound and │
│ │ extent of a datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_value_index(value, index) │ Return a predefined pair datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Match_size(typeclass, size) │ Find a datatype matching a specified │
│ │ size in bytes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Pack(inbuf, outbuf, position, comm) │ Pack into contiguous memory according │
│ │ to datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Pack_external(datarep, inbuf, outbuf, │ Pack into contiguous memory according │
│ position) │ to datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Pack_external_size(datarep, count) │ Determine the amount of space needed │
│ │ to pack a message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Pack_size(count, comm) │ Determine the amount of space needed │
│ │ to pack a message. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_attr(keyval, attrval) │ Store attribute value associated with │
│ │ a key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_name(name) │ Set the print name for this datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Unpack(inbuf, position, outbuf, comm) │ Unpack from contiguous memory │
│ │ according to datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Unpack_external(datarep, inbuf, │ Unpack from contiguous memory │
│ position, outbuf) │ according to datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ decode() │ Convenience method for decoding a │
│ │ datatype. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null or predefined. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromcode(code) │ Get predefined MPI datatype from │
│ │ character code or type string. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ tocode() │ Get character code or type string │
│ │ from predefined MPI datatype. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌───────────────┬───────────────────────────┐
│ combiner │ Combiner. │
├───────────────┼───────────────────────────┤
│ contents │ Contents. │
├───────────────┼───────────────────────────┤
│ envelope │ Envelope. │
├───────────────┼───────────────────────────┤
│ extent │ Extent. │
├───────────────┼───────────────────────────┤
│ handle │ MPI handle. │
├───────────────┼───────────────────────────┤
│ is_named │ Is a named datatype. │
├───────────────┼───────────────────────────┤
│ is_predefined │ Is a predefined datatype. │
├───────────────┼───────────────────────────┤
│ lb │ Lower bound. │
├───────────────┼───────────────────────────┤
│ name │ Print name. │
├───────────────┼───────────────────────────┤
│ size │ Size (in bytes). │
├───────────────┼───────────────────────────┤
│ true_extent │ True extent. │
├───────────────┼───────────────────────────┤
│ true_lb │ True lower bound. │
├───────────────┼───────────────────────────┤
│ true_ub │ True upper bound. │
├───────────────┼───────────────────────────┤
│ typechar │ Character code. │
├───────────────┼───────────────────────────┤
│ typestr │ Type string. │
├───────────────┼───────────────────────────┤
│ ub │ Upper bound. │
└───────────────┴───────────────────────────┘
Methods Documentation
Commit()
Commit the datatype.
Return type
Self
Create_contiguous(count)
Create a contiguous datatype.
Parameters
count (int)
Return type
Self
Create_darray(size, rank, gsizes, distribs, dargs, psizes, order=ORDER_C)
Create a datatype for a distributed array on Cartesian process grids.
Parameters
• size (int)
• rank (int)
• gsizes (Sequence[int])
• distribs (Sequence[int])
• dargs (Sequence[int])
• psizes (Sequence[int])
• order (int)
Return type
Self
classmethod Create_f90_complex(p, r)
Return a bounded complex datatype.
Parameters
• p (int)
• r (int)
Return type
Self
classmethod Create_f90_integer(r)
Return a bounded integer datatype.
Parameters
r (int)
Return type
Self
classmethod Create_f90_real(p, r)
Return a bounded real datatype.
Parameters
• p (int)
• r (int)
Return type
Self
Create_hindexed(blocklengths, displacements)
Create an indexed datatype.
NOTE:
Displacements are measured in bytes.
Parameters
• blocklengths (Sequence[int])
• displacements (Sequence[int])
Return type
Self
Create_hindexed_block(blocklength, displacements)
Create an indexed datatype with constant-sized blocks.
NOTE:
Displacements are measured in bytes.
Parameters
• blocklength (int)
• displacements (Sequence[int])
Return type
Self
Create_hvector(count, blocklength, stride)
Create a vector (strided) datatype with stride in bytes.
Parameters
• count (int)
• blocklength (int)
• stride (int)
Return type
Self
Create_indexed(blocklengths, displacements)
Create an indexed datatype.
Parameters
• blocklengths (Sequence[int])
• displacements (Sequence[int])
Return type
Self
Create_indexed_block(blocklength, displacements)
Create an indexed datatype with constant-sized blocks.
Parameters
• blocklength (int)
• displacements (Sequence[int])
Return type
Self
classmethod Create_keyval(copy_fn=None, delete_fn=None, nopython=False)
Create a new attribute key for datatypes.
Parameters
• copy_fn (Callable[[Datatype, int, Any], Any] | None)
• delete_fn (Callable[[Datatype, int, Any], None] | None)
• nopython (bool)
Return type
int
Create_resized(lb, extent)
Create a datatype with a new lower bound and extent.
Parameters
• lb (int)
• extent (int)
Return type
Self
classmethod Create_struct(blocklengths, displacements, datatypes)
Create a general composite (struct) datatype.
NOTE:
Displacements are measured in bytes.
Parameters
• blocklengths (Sequence[int])
• displacements (Sequence[int])
• datatypes (Sequence[Datatype])
Return type
Self
Create_subarray(sizes, subsizes, starts, order=ORDER_C)
Create a datatype for a subarray of a multidimensional array.
Parameters
• sizes (Sequence[int])
• subsizes (Sequence[int])
• starts (Sequence[int])
• order (int)
Return type
Self
Create_vector(count, blocklength, stride)
Create a vector (strided) datatype.
Parameters
• count (int)
• blocklength (int)
• stride (int)
Return type
Self
Delete_attr(keyval)
Delete attribute value associated with a key.
Parameters
keyval (int)
Return type
None
Dup() Duplicate a datatype.
Return type
Self
Free() Free the datatype.
Return type
None
classmethod Free_keyval(keyval)
Free an attribute key for datatypes.
Parameters
keyval (int)
Return type
int
Get_attr(keyval)
Retrieve attribute value by key.
Parameters
keyval (int)
Return type
int | Any | None
Get_contents()
Return the input arguments used to create a datatype.
Return type
tuple[list[int], list[int], list[int], list[Datatype]]
Get_envelope()
Return the number of input arguments used to create a datatype.
Return type
tuple[int, int, int, int, int]
Get_extent()
Return lower bound and extent of datatype.
Return type
tuple[int, int]
Get_name()
Get the print name for this datatype.
Return type
str
Get_size()
Return the number of bytes occupied by entries in the datatype.
Return type
int
Get_true_extent()
Return the true lower bound and extent of a datatype.
Return type
tuple[int, int]
classmethod Get_value_index(value, index)
Return a predefined pair datatype.
Parameters
• value (Datatype)
• index (Datatype)
Return type
Self
classmethod Match_size(typeclass, size)
Find a datatype matching a specified size in bytes.
Parameters
• typeclass (int)
• size (int)
Return type
Self
Pack(inbuf, outbuf, position, comm)
Pack into contiguous memory according to datatype.
Parameters
• inbuf (BufSpec)
• outbuf (BufSpec)
• position (int)
• comm (Comm)
Return type
int
Pack_external(datarep, inbuf, outbuf, position)
Pack into contiguous memory according to datatype.
Uses the portable data representation external32.
Parameters
• datarep (str)
• inbuf (BufSpec)
• outbuf (BufSpec)
• position (int)
Return type
int
Pack_external_size(datarep, count)
Determine the amount of space needed to pack a message.
Uses the portable data representation external32.
NOTE:
Returns an upper bound measured in bytes.
Parameters
• datarep (str)
• count (int)
Return type
int
Pack_size(count, comm)
Determine the amount of space needed to pack a message.
NOTE:
Returns an upper bound measured in bytes.
Parameters
• count (int)
• comm (Comm)
Return type
int
Set_attr(keyval, attrval)
Store attribute value associated with a key.
Parameters
• keyval (int)
• attrval (Any)
Return type
None
Set_name(name)
Set the print name for this datatype.
Parameters
name (str)
Return type
None
Unpack(inbuf, position, outbuf, comm)
Unpack from contiguous memory according to datatype.
Parameters
• inbuf (BufSpec)
• position (int)
• outbuf (BufSpec)
• comm (Comm)
Return type
int
Unpack_external(datarep, inbuf, position, outbuf)
Unpack from contiguous memory according to datatype.
Uses the portable data representation external32.
Parameters
• datarep (str)
• inbuf (BufSpec)
• position (int)
• outbuf (BufSpec)
Return type
int
decode()
Convenience method for decoding a datatype.
Return type
tuple[Datatype, str, dict[str, Any]]
classmethod f2py(arg)
Parameters
arg (int)
Return type
Datatype
free() Call Free if not null or predefined.
Return type
None
classmethod fromcode(code)
Get predefined MPI datatype from character code or type string.
Parameters
code (str)
Return type
Datatype
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Datatype
py2f()
Return type
int
tocode()
Get character code or type string from predefined MPI datatype.
Return type
str
Attributes Documentation
combiner
Combiner.
contents
Contents.
envelope
Envelope.
extent Extent.
handle MPI handle.
is_named
Is a named datatype.
is_predefined
Is a predefined datatype.
lb Lower bound.
name Print name.
size Size (in bytes).
true_extent
True extent.
true_lb
True lower bound.
true_ub
True upper bound.
typechar
Character code.
typestr
Type string.
ub Upper bound.
mpi4py.MPI.Distgraphcomm
class mpi4py.MPI.Distgraphcomm
Bases: Topocomm
Distributed graph topology intracommunicator.
static __new__(cls, comm=None)
Parameters
comm (Distgraphcomm | None)
Return type
Self
Methods Summary
┌────────────────────────────┬───────────────────────────────────────┐
│ Get_dist_neighbors() │ Return adjacency information for a │
│ │ distributed graph topology. │
├────────────────────────────┼───────────────────────────────────────┤
│ Get_dist_neighbors_count() │ Return adjacency information for a │
│ │ distributed graph topology. │
└────────────────────────────┴───────────────────────────────────────┘
Methods Documentation
Get_dist_neighbors()
Return adjacency information for a distributed graph topology.
Return type
tuple[list[int], list[int], tuple[list[int], list[int]] | None]
Get_dist_neighbors_count()
Return adjacency information for a distributed graph topology.
Return type
int
mpi4py.MPI.Errhandler
class mpi4py.MPI.Errhandler
Bases: object
Error handler.
static __new__(cls, errhandler=None)
Parameters
errhandler (Errhandler | None)
Return type
Self
Methods Summary
┌────────────────────┬────────────────────────────────┐
│ Free() │ Free an error handler. │
├────────────────────┼────────────────────────────────┤
│ f2py(arg) │ │
├────────────────────┼────────────────────────────────┤
│ free() │ Call Free if not null. │
├────────────────────┼────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├────────────────────┼────────────────────────────────┤
│ py2f() │ │
└────────────────────┴────────────────────────────────┘
Attributes Summary
┌────────┬─────────────┐
│ handle │ MPI handle. │
└────────┴─────────────┘
Methods Documentation
Free() Free an error handler.
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
Errhandler
free() Call Free if not null.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Errhandler
py2f()
Return type
int
Attributes Documentation
handle MPI handle.
mpi4py.MPI.File
class mpi4py.MPI.File
Bases: object
File I/O context.
static __new__(cls, file=None)
Parameters
file (File | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Call_errhandler(errorcode) │ Call the error handler installed on a │
│ │ file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Close() │ Close a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_errhandler(errhandler_fn) │ Create a new error handler for files. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Delete(filename[, info]) │ Delete a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_amode() │ Return the file access mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_atomicity() │ Return the atomicity mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_byte_offset(offset) │ Return the absolute byte position in │
│ │ the file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_errhandler() │ Get the error handler for a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_group() │ Access the group of processes that │
│ │ opened the file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_info() │ Return the current hints for a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_position() │ Return the current position of the │
│ │ individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_position_shared() │ Return the current position of the │
│ │ shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_size() │ Return the file size. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_type_extent(datatype) │ Return the extent of datatype in the │
│ │ file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_view() │ Return the file view. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iread(buf) │ Nonblocking read using individual │
│ │ file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iread_all(buf) │ Nonblocking collective read using │
│ │ individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iread_at(offset, buf) │ Nonblocking read using explicit │
│ │ offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iread_at_all(offset, buf) │ Nonblocking collective read using │
│ │ explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iread_shared(buf) │ Nonblocking read using shared file │
│ │ pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iwrite(buf) │ Nonblocking write using individual │
│ │ file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iwrite_all(buf) │ Nonblocking collective write using │
│ │ individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iwrite_at(offset, buf) │ Nonblocking write using explicit │
│ │ offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iwrite_at_all(offset, buf) │ Nonblocking collective write using │
│ │ explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iwrite_shared(buf) │ Nonblocking write using shared file │
│ │ pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Open(comm, filename[, amode, info]) │ Open a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Preallocate(size) │ Preallocate storage space for a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read(buf[, status]) │ Read using individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_all(buf[, status]) │ Collective read using individual file │
│ │ pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_all_begin(buf) │ Start a split collective read using │
│ │ individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_all_end(buf[, status]) │ Complete a split collective read │
│ │ using individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_at(offset, buf[, status]) │ Read using explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_at_all(offset, buf[, status]) │ Collective read using explicit │
│ │ offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_at_all_begin(offset, buf) │ Start a split collective read using │
│ │ explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_at_all_end(buf[, status]) │ Complete a split collective read │
│ │ using explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_ordered(buf[, status]) │ Collective read using shared file │
│ │ pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_ordered_begin(buf) │ Start a split collective read using │
│ │ shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_ordered_end(buf[, status]) │ Complete a split collective read │
│ │ using shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Read_shared(buf[, status]) │ Read using shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Seek(offset[, whence]) │ Update the individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Seek_shared(offset[, whence]) │ Update the shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_atomicity(flag) │ Set the atomicity mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_errhandler(errhandler) │ Set the error handler for a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_info(info) │ Set new values for the hints │
│ │ associated with a file. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_size(size) │ Set the file size. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_view([disp, etype, filetype, │ Set the file view. │
│ datarep, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Sync() │ Causes all previous writes to be │
│ │ transferred to the storage device. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write(buf[, status]) │ Write using individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_all(buf[, status]) │ Collective write using individual │
│ │ file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_all_begin(buf) │ Start a split collective write using │
│ │ individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_all_end(buf[, status]) │ Complete a split collective write │
│ │ using individual file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_at(offset, buf[, status]) │ Write using explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_at_all(offset, buf[, status]) │ Collective write using explicit │
│ │ offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_at_all_begin(offset, buf) │ Start a split collective write using │
│ │ explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_at_all_end(buf[, status]) │ Complete a split collective write │
│ │ using explicit offset. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_ordered(buf[, status]) │ Collective write using shared file │
│ │ pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_ordered_begin(buf) │ Start a split collective write using │
│ │ shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_ordered_end(buf[, status]) │ Complete a split collective write │
│ │ using shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Write_shared(buf[, status]) │ Write using shared file pointer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Close if not null. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────────┬──────────────────┐
│ amode │ Access mode. │
├────────────┼──────────────────┤
│ atomicity │ Atomicity mode. │
├────────────┼──────────────────┤
│ group │ Group. │
├────────────┼──────────────────┤
│ group_rank │ Group rank. │
├────────────┼──────────────────┤
│ group_size │ Group size. │
├────────────┼──────────────────┤
│ handle │ MPI handle. │
├────────────┼──────────────────┤
│ info │ Info hints. │
├────────────┼──────────────────┤
│ size │ Size (in bytes). │
└────────────┴──────────────────┘
Methods Documentation
Call_errhandler(errorcode)
Call the error handler installed on a file.
Parameters
errorcode (int)
Return type
None
Close()
Close a file.
Return type
None
classmethod Create_errhandler(errhandler_fn)
Create a new error handler for files.
Parameters
errhandler_fn (Callable[[File, int], None])
Return type
Errhandler
classmethod Delete(filename, info=INFO_NULL)
Delete a file.
Parameters
• filename (PathLike | str | bytes)
• info (Info)
Return type
None
Get_amode()
Return the file access mode.
Return type
int
Get_atomicity()
Return the atomicity mode.
Return type
bool
Get_byte_offset(offset)
Return the absolute byte position in the file.
NOTE:
Input offset is measured in etype units relative to the current file view.
Parameters
offset (int)
Return type
int
Get_errhandler()
Get the error handler for a file.
Return type
Errhandler
Get_group()
Access the group of processes that opened the file.
Return type
Group
Get_info()
Return the current hints for a file.
Return type
Info
Get_position()
Return the current position of the individual file pointer.
NOTE:
Position is measured in etype units relative to the current file view.
Return type
int
Get_position_shared()
Return the current position of the shared file pointer.
NOTE:
Position is measured in etype units relative to the current view.
Return type
int
Get_size()
Return the file size.
Return type
int
Get_type_extent(datatype)
Return the extent of datatype in the file.
Parameters
datatype (Datatype)
Return type
int
Get_view()
Return the file view.
Return type
tuple[int, Datatype, Datatype, str]
Iread(buf)
Nonblocking read using individual file pointer.
Parameters
buf (BufSpec)
Return type
Request
Iread_all(buf)
Nonblocking collective read using individual file pointer.
Parameters
buf (BufSpec)
Return type
Request
Iread_at(offset, buf)
Nonblocking read using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
Return type
Request
Iread_at_all(offset, buf)
Nonblocking collective read using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
Return type
Request
Iread_shared(buf)
Nonblocking read using shared file pointer.
Parameters
buf (BufSpec)
Return type
Request
Iwrite(buf)
Nonblocking write using individual file pointer.
Parameters
buf (BufSpec)
Return type
Request
Iwrite_all(buf)
Nonblocking collective write using individual file pointer.
Parameters
buf (BufSpec)
Return type
Request
Iwrite_at(offset, buf)
Nonblocking write using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
Return type
Request
Iwrite_at_all(offset, buf)
Nonblocking collective write using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
Return type
Request
Iwrite_shared(buf)
Nonblocking write using shared file pointer.
Parameters
buf (BufSpec)
Return type
Request
classmethod Open(comm, filename, amode=MODE_RDONLY, info=INFO_NULL)
Open a file.
Parameters
• comm (Intracomm)
• filename (PathLike | str | bytes)
• amode (int)
• info (Info)
Return type
Self
Preallocate(size)
Preallocate storage space for a file.
Parameters
size (int)
Return type
None
Read(buf, status=None)
Read using individual file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_all(buf, status=None)
Collective read using individual file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_all_begin(buf)
Start a split collective read using individual file pointer.
Parameters
buf (BufSpec)
Return type
None
Read_all_end(buf, status=None)
Complete a split collective read using individual file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_at(offset, buf, status=None)
Read using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_at_all(offset, buf, status=None)
Collective read using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_at_all_begin(offset, buf)
Start a split collective read using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
Return type
None
Read_at_all_end(buf, status=None)
Complete a split collective read using explicit offset.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_ordered(buf, status=None)
Collective read using shared file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_ordered_begin(buf)
Start a split collective read using shared file pointer.
Parameters
buf (BufSpec)
Return type
None
Read_ordered_end(buf, status=None)
Complete a split collective read using shared file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Read_shared(buf, status=None)
Read using shared file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Seek(offset, whence=SEEK_SET)
Update the individual file pointer.
Parameters
• offset (int)
• whence (int)
Return type
None
Seek_shared(offset, whence=SEEK_SET)
Update the shared file pointer.
Parameters
• offset (int)
• whence (int)
Return type
None
Set_atomicity(flag)
Set the atomicity mode.
Parameters
flag (bool)
Return type
None
Set_errhandler(errhandler)
Set the error handler for a file.
Parameters
errhandler (Errhandler)
Return type
None
Set_info(info)
Set new values for the hints associated with a file.
Parameters
info (Info)
Return type
None
Set_size(size)
Set the file size.
Parameters
size (int)
Return type
None
Set_view(disp=0, etype=BYTE, filetype=None, datarep='native', info=INFO_NULL)
Set the file view.
Parameters
• disp (int)
• etype (Datatype)
• filetype (Datatype | None)
• datarep (str)
• info (Info)
Return type
None
Sync() Causes all previous writes to be transferred to the storage device.
Return type
None
Write(buf, status=None)
Write using individual file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_all(buf, status=None)
Collective write using individual file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_all_begin(buf)
Start a split collective write using individual file pointer.
Parameters
buf (BufSpec)
Return type
None
Write_all_end(buf, status=None)
Complete a split collective write using individual file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_at(offset, buf, status=None)
Write using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_at_all(offset, buf, status=None)
Collective write using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_at_all_begin(offset, buf)
Start a split collective write using explicit offset.
Parameters
• offset (int)
• buf (BufSpec)
Return type
None
Write_at_all_end(buf, status=None)
Complete a split collective write using explicit offset.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_ordered(buf, status=None)
Collective write using shared file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_ordered_begin(buf)
Start a split collective write using shared file pointer.
Parameters
buf (BufSpec)
Return type
None
Write_ordered_end(buf, status=None)
Complete a split collective write using shared file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
Write_shared(buf, status=None)
Write using shared file pointer.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
File
free() Call Close if not null.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
File
py2f()
Return type
int
Attributes Documentation
amode Access mode.
atomicity
Atomicity mode.
group Group.
group_rank
Group rank.
group_size
Group size.
handle MPI handle.
info Info hints.
size Size (in bytes).
mpi4py.MPI.Graphcomm
class mpi4py.MPI.Graphcomm
Bases: Topocomm
General graph topology intracommunicator.
static __new__(cls, comm=None)
Parameters
comm (Graphcomm | None)
Return type
Self
Methods Summary
┌───────────────────────────┬───────────────────────────────────────┐
│ Get_dims() │ Return the number of nodes and edges. │
├───────────────────────────┼───────────────────────────────────────┤
│ Get_neighbors(rank) │ Return list of neighbors of a │
│ │ process. │
├───────────────────────────┼───────────────────────────────────────┤
│ Get_neighbors_count(rank) │ Return number of neighbors of a │
│ │ process. │
├───────────────────────────┼───────────────────────────────────────┤
│ Get_topo() │ Return index and edges. │
└───────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────────┬────────────────────────────┐
│ dims │ Number of nodes and edges. │
├────────────┼────────────────────────────┤
│ edges │ Edges. │
├────────────┼────────────────────────────┤
│ index │ Index. │
├────────────┼────────────────────────────┤
│ nedges │ Number of edges. │
├────────────┼────────────────────────────┤
│ neighbors │ Neighbors. │
├────────────┼────────────────────────────┤
│ nneighbors │ Number of neighbors. │
├────────────┼────────────────────────────┤
│ nnodes │ Number of nodes. │
├────────────┼────────────────────────────┤
│ topo │ Topology information. │
└────────────┴────────────────────────────┘
Methods Documentation
Get_dims()
Return the number of nodes and edges.
Return type
tuple[int, int]
Get_neighbors(rank)
Return list of neighbors of a process.
Parameters
rank (int)
Return type
list[int]
Get_neighbors_count(rank)
Return number of neighbors of a process.
Parameters
rank (int)
Return type
int
Get_topo()
Return index and edges.
Return type
tuple[list[int], list[int]]
Attributes Documentation
dims Number of nodes and edges.
edges Edges.
index Index.
nedges Number of edges.
neighbors
Neighbors.
nneighbors
Number of neighbors.
nnodes Number of nodes.
topo Topology information.
mpi4py.MPI.Grequest
class mpi4py.MPI.Grequest
Bases: Request
Generalized request handler.
static __new__(cls, request=None)
Parameters
request (Grequest | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Complete() │ Notify that a user-defined request is │
│ │ complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Start([query_fn, free_fn, cancel_fn, │ Create and return a user-defined │
│ args, ...]) │ request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ complete([obj]) │ Notify that a user-defined request is │
│ │ complete. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Methods Documentation
Complete()
Notify that a user-defined request is complete.
Return type
None
classmethod Start(query_fn=None, free_fn=None, cancel_fn=None, args=None, kwargs=None)
Create and return a user-defined request.
Parameters
• query_fn (Callable[[...], None] | None)
• free_fn (Callable[[...], None] | None)
• cancel_fn (Callable[[...], None] | None)
• args (tuple[Any] | None)
• kwargs (dict[str, Any] | None)
Return type
Grequest
complete(obj=None)
Notify that a user-defined request is complete.
Parameters
obj (Any)
Return type
None
mpi4py.MPI.Group
class mpi4py.MPI.Group
Bases: object
Group of processes.
static __new__(cls, group=None)
Parameters
group (Group | None)
Return type
Self
Methods Summary
┌───────────────────────────────────┬───────────────────────────────────────┐
│ Compare(group) │ Compare two groups. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Create_from_session_pset(session, │ Create a new group from session and │
│ pset_name) │ process set. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Difference(group1, group2) │ Create a new group from the │
│ │ difference of two existing groups. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Dup() │ Duplicate a group. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Excl(ranks) │ Create a new group by excluding │
│ │ listed members. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Free() │ Free a group. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Get_rank() │ Return the rank of this process in a │
│ │ group. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Get_size() │ Return the number of processes in a │
│ │ group. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Incl(ranks) │ Create a new group by including │
│ │ listed members. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Intersection(group1, group2) │ Create a new group from the │
│ │ intersection of two existing groups. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Range_excl(ranks) │ Create a new group by excluding │
│ │ ranges of members. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Range_incl(ranks) │ Create a new group by including │
│ │ ranges of members. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Translate_ranks([ranks, group]) │ Translate ranks in a group to those │
│ │ in another group. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ Union(group1, group2) │ Create a new group from the union of │
│ │ two existing groups. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null or predefined. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
└───────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────┬───────────────────────┐
│ handle │ MPI handle. │
├────────┼───────────────────────┤
│ rank │ Rank of this process. │
├────────┼───────────────────────┤
│ size │ Number of processes. │
└────────┴───────────────────────┘
Methods Documentation
Compare(group)
Compare two groups.
Parameters
group (Group)
Return type
int
classmethod Create_from_session_pset(session, pset_name)
Create a new group from session and process set.
Parameters
• session (Session)
• pset_name (str)
Return type
Self
classmethod Difference(group1, group2)
Create a new group from the difference of two existing groups.
Parameters
• group1 (Group)
• group2 (Group)
Return type
Self
Dup() Duplicate a group.
Return type
Self
Excl(ranks)
Create a new group by excluding listed members.
Parameters
ranks (Sequence[int])
Return type
Self
Free() Free a group.
Return type
None
Get_rank()
Return the rank of this process in a group.
Return type
int
Get_size()
Return the number of processes in a group.
Return type
int
Incl(ranks)
Create a new group by including listed members.
Parameters
ranks (Sequence[int])
Return type
Self
classmethod Intersection(group1, group2)
Create a new group from the intersection of two existing groups.
Parameters
• group1 (Group)
• group2 (Group)
Return type
Self
Range_excl(ranks)
Create a new group by excluding ranges of members.
Parameters
ranks (Sequence[tuple[int, int, int]])
Return type
Self
Range_incl(ranks)
Create a new group by including ranges of members.
Parameters
ranks (Sequence[tuple[int, int, int]])
Return type
Self
Translate_ranks(ranks=None, group=None)
Translate ranks in a group to those in another group.
Parameters
• ranks (Sequence[int] | None)
• group (Group | None)
Return type
list[int]
classmethod Union(group1, group2)
Create a new group from the union of two existing groups.
Parameters
• group1 (Group)
• group2 (Group)
Return type
Self
classmethod f2py(arg)
Parameters
arg (int)
Return type
Group
free() Call Free if not null or predefined.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Group
py2f()
Return type
int
Attributes Documentation
handle MPI handle.
rank Rank of this process.
size Number of processes.
mpi4py.MPI.InPlaceType
class mpi4py.MPI.InPlaceType
Bases: int
Type of IN_PLACE.
static __new__(cls)
Return type
Self
mpi4py.MPI.Info
class mpi4py.MPI.Info
Bases: object
Info object.
static __new__(cls, info=None)
Parameters
info (Info | None)
Return type
Self
Methods Summary
┌─────────────────────┬───────────────────────────────────────┐
│ Create([items]) │ Create a new info object. │
├─────────────────────┼───────────────────────────────────────┤
│ Create_env([args]) │ Create a new environment info object. │
├─────────────────────┼───────────────────────────────────────┤
│ Delete(key) │ Remove a (key, value) pair from info. │
├─────────────────────┼───────────────────────────────────────┤
│ Dup() │ Duplicate an existing info object. │
├─────────────────────┼───────────────────────────────────────┤
│ Free() │ Free an info object. │
├─────────────────────┼───────────────────────────────────────┤
│ Get(key) │ Retrieve the value associated with a │
│ │ key. │
├─────────────────────┼───────────────────────────────────────┤
│ Get_nkeys() │ Return the number of currently │
│ │ defined keys in info. │
├─────────────────────┼───────────────────────────────────────┤
│ Get_nthkey(n) │ Return the n-th defined key in info. │
├─────────────────────┼───────────────────────────────────────┤
│ Set(key, value) │ Store a value associated with a key. │
├─────────────────────┼───────────────────────────────────────┤
│ clear() │ Clear contents. │
├─────────────────────┼───────────────────────────────────────┤
│ copy() │ Copy contents. │
├─────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├─────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null or predefined. │
├─────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├─────────────────────┼───────────────────────────────────────┤
│ get(key[, default]) │ Retrieve value by key. │
├─────────────────────┼───────────────────────────────────────┤
│ items() │ Return list of items. │
├─────────────────────┼───────────────────────────────────────┤
│ keys() │ Return list of keys. │
├─────────────────────┼───────────────────────────────────────┤
│ pop(key, *default) │ Pop value by key. │
├─────────────────────┼───────────────────────────────────────┤
│ popitem() │ Pop first item. │
├─────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
├─────────────────────┼───────────────────────────────────────┤
│ update([items]) │ Update contents. │
├─────────────────────┼───────────────────────────────────────┤
│ values() │ Return list of values. │
└─────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────┬─────────────┐
│ handle │ MPI handle. │
└────────┴─────────────┘
Methods Documentation
classmethod Create(items=None)
Create a new info object.
Parameters
items (Info | Mapping[str, str] | Iterable[tuple[str, str]] | None)
Return type
Self
classmethod Create_env(args=None)
Create a new environment info object.
Parameters
args (Sequence[str] | None)
Return type
Self
Delete(key)
Remove a (key, value) pair from info.
Parameters
key (str)
Return type
None
Dup() Duplicate an existing info object.
Return type
Self
Free() Free an info object.
Return type
None
Get(key)
Retrieve the value associated with a key.
Parameters
key (str)
Return type
str | None
Get_nkeys()
Return the number of currently defined keys in info.
Return type
int
Get_nthkey(n)
Return the n-th defined key in info.
Parameters
n (int)
Return type
str
Set(key, value)
Store a value associated with a key.
Parameters
• key (str)
• value (str)
Return type
None
clear()
Clear contents.
Return type
None
copy() Copy contents.
Return type
Self
classmethod f2py(arg)
Parameters
arg (int)
Return type
Info
free() Call Free if not null or predefined.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Info
get(key, default=None)
Retrieve value by key.
Parameters
• key (str)
• default (str | None)
Return type
str | None
items()
Return list of items.
Return type
list[tuple[str, str]]
keys() Return list of keys.
Return type
list[str]
pop(key, *default)
Pop value by key.
Parameters
• key (str)
• default (str)
Return type
str
popitem()
Pop first item.
Return type
tuple[str, str]
py2f()
Return type
int
update(items=(), **kwds)
Update contents.
Parameters
• items (Info | Mapping[str, str] | Iterable[tuple[str, str]])
• kwds (str)
Return type
None
values()
Return list of values.
Return type
list[str]
Attributes Documentation
handle MPI handle.
mpi4py.MPI.Intercomm
class mpi4py.MPI.Intercomm
Bases: Comm
Intercommunicator.
static __new__(cls, comm=None)
Parameters
comm (Intercomm | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Create_from_groups(local_group, ...[, │ Create communicator from group. │
│ ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_remote_group() │ Access the remote group associated │
│ │ with the inter-communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_remote_size() │ Intercommunicator remote size. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Merge([high]) │ Merge intercommunicator into an │
│ │ intracommunicator. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌──────────────┬─────────────────────────────┐
│ remote_group │ Remote group. │
├──────────────┼─────────────────────────────┤
│ remote_size │ Number of remote processes. │
└──────────────┴─────────────────────────────┘
Methods Documentation
classmethod Create_from_groups(local_group, local_leader, remote_group, remote_leader,
stringtag='org.mpi4py', info=INFO_NULL, errhandler=None)
Create communicator from group.
Parameters
• local_group (Group)
• local_leader (int)
• remote_group (Group)
• remote_leader (int)
• stringtag (str)
• info (Info)
• errhandler (Errhandler | None)
Return type
Intracomm
Get_remote_group()
Access the remote group associated with the inter-communicator.
Return type
Group
Get_remote_size()
Intercommunicator remote size.
Return type
int
Merge(high=False)
Merge intercommunicator into an intracommunicator.
Parameters
high (bool)
Return type
Intracomm
Attributes Documentation
remote_group
Remote group.
remote_size
Number of remote processes.
mpi4py.MPI.Intracomm
class mpi4py.MPI.Intracomm
Bases: Comm
Intracommunicator.
static __new__(cls, comm=None)
Parameters
comm (Intracomm | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Accept(port_name[, info, root]) │ Accept a request to form a new │
│ │ intercommunicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Cart_map(dims[, periods]) │ Determine optimal process placement │
│ │ on a Cartesian topology. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Connect(port_name[, info, root]) │ Make a request to form a new │
│ │ intercommunicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_cart(dims[, periods, reorder]) │ Create cartesian communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_dist_graph(sources, degrees, │ Create distributed graph │
│ destinations) │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_dist_graph_adjacent(sources, │ Create distributed graph │
│ destinations) │ communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_from_group(group[, stringtag, │ Create communicator from group. │
│ info, ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_graph(index, edges[, reorder]) │ Create graph communicator. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_group(group[, tag]) │ Create communicator from group. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_intercomm(local_leader, │ Create intercommunicator. │
│ peer_comm, ...) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Exscan(sendbuf, recvbuf[, op]) │ Exclusive Scan. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Exscan_init(sendbuf, recvbuf[, op, │ Persistent Exclusive Scan. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Graph_map(index, edges) │ Determine optimal process placement │
│ │ on a graph topology. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iexscan(sendbuf, recvbuf[, op]) │ Inclusive Scan. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iscan(sendbuf, recvbuf[, op]) │ Inclusive Scan. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Scan(sendbuf, recvbuf[, op]) │ Inclusive Scan. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Scan_init(sendbuf, recvbuf[, op, │ Persistent Inclusive Scan. │
│ info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Spawn(command[, args, maxprocs, info, │ Spawn instances of a single MPI │
│ root, ...]) │ application. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Spawn_multiple(command[, args, │ Spawn instances of multiple MPI │
│ maxprocs, ...]) │ applications. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ exscan(sendobj[, op]) │ Exclusive Scan. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ scan(sendobj[, op]) │ Inclusive Scan. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Methods Documentation
Accept(port_name, info=INFO_NULL, root=0)
Accept a request to form a new intercommunicator.
Parameters
• port_name (str)
• info (Info)
• root (int)
Return type
Intercomm
Cart_map(dims, periods=None)
Determine optimal process placement on a Cartesian topology.
Parameters
• dims (Sequence[int])
• periods (Sequence[bool] | None)
Return type
int
Connect(port_name, info=INFO_NULL, root=0)
Make a request to form a new intercommunicator.
Parameters
• port_name (str)
• info (Info)
• root (int)
Return type
Intercomm
Create_cart(dims, periods=None, reorder=False)
Create cartesian communicator.
Parameters
• dims (Sequence[int])
• periods (Sequence[bool] | None)
• reorder (bool)
Return type
Cartcomm
Create_dist_graph(sources, degrees, destinations, weights=None, info=INFO_NULL, reorder=False)
Create distributed graph communicator.
Parameters
• sources (Sequence[int])
• degrees (Sequence[int])
• destinations (Sequence[int])
• weights (Sequence[int] | None)
• info (Info)
• reorder (bool)
Return type
Distgraphcomm
Create_dist_graph_adjacent(sources, destinations, sourceweights=None, destweights=None,
info=INFO_NULL, reorder=False)
Create distributed graph communicator.
Parameters
• sources (Sequence[int])
• destinations (Sequence[int])
• sourceweights (Sequence[int] | None)
• destweights (Sequence[int] | None)
• info (Info)
• reorder (bool)
Return type
Distgraphcomm
classmethod Create_from_group(group, stringtag='org.mpi4py', info=INFO_NULL, errhandler=None)
Create communicator from group.
Parameters
• group (Group)
• stringtag (str)
• info (Info)
• errhandler (Errhandler | None)
Return type
Intracomm
Create_graph(index, edges, reorder=False)
Create graph communicator.
Parameters
• index (Sequence[int])
• edges (Sequence[int])
• reorder (bool)
Return type
Graphcomm
Create_group(group, tag=0)
Create communicator from group.
Parameters
• group (Group)
• tag (int)
Return type
Intracomm
Create_intercomm(local_leader, peer_comm, remote_leader, tag=0)
Create intercommunicator.
Parameters
• local_leader (int)
• peer_comm (Intracomm)
• remote_leader (int)
• tag (int)
Return type
Intercomm
Exscan(sendbuf, recvbuf, op=SUM)
Exclusive Scan.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
Return type
None
Exscan_init(sendbuf, recvbuf, op=SUM, info=INFO_NULL)
Persistent Exclusive Scan.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
• info (Info)
Return type
Prequest
Graph_map(index, edges)
Determine optimal process placement on a graph topology.
Parameters
• index (Sequence[int])
• edges (Sequence[int])
Return type
int
Iexscan(sendbuf, recvbuf, op=SUM)
Inclusive Scan.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
Return type
Request
Iscan(sendbuf, recvbuf, op=SUM)
Inclusive Scan.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
Return type
Request
Scan(sendbuf, recvbuf, op=SUM)
Inclusive Scan.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
Return type
None
Scan_init(sendbuf, recvbuf, op=SUM, info=INFO_NULL)
Persistent Inclusive Scan.
Parameters
• sendbuf (BufSpec | InPlace)
• recvbuf (BufSpec)
• op (Op)
• info (Info)
Return type
Prequest
Spawn(command, args=None, maxprocs=1, info=INFO_NULL, root=0, errcodes=None)
Spawn instances of a single MPI application.
Parameters
• command (str)
• args (Sequence[str] | None)
• maxprocs (int)
• info (Info)
• root (int)
• errcodes (list[int] | None)
Return type
Intercomm
Spawn_multiple(command, args=None, maxprocs=None, info=INFO_NULL, root=0, errcodes=None)
Spawn instances of multiple MPI applications.
Parameters
• command (Sequence[str])
• args (Sequence[Sequence[str]] | None)
• maxprocs (Sequence[int] | None)
• info (Sequence[Info] | Info)
• root (int)
• errcodes (list[list[int]] | None)
Return type
Intercomm
exscan(sendobj, op=SUM)
Exclusive Scan.
Parameters
• sendobj (Any)
• op (Op | Callable[[Any, Any], Any])
Return type
Any
scan(sendobj, op=SUM)
Inclusive Scan.
Parameters
• sendobj (Any)
• op (Op | Callable[[Any, Any], Any])
Return type
Any
mpi4py.MPI.Message
class mpi4py.MPI.Message
Bases: object
Matched message.
static __new__(cls, message=None)
Parameters
message (Message | None)
Return type
Self
Methods Summary
┌─────────────────────────────────────┬───────────────────────────────────────┐
│ Iprobe(comm[, source, tag, status]) │ Nonblocking test for a matched │
│ │ message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Irecv(buf) │ Nonblocking receive of matched │
│ │ message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Probe(comm[, source, tag, status]) │ Blocking test for a matched message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ Recv(buf[, status]) │ Blocking receive of matched message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Do nothing. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ iprobe(comm[, source, tag, status]) │ Nonblocking test for a matched │
│ │ message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ irecv() │ Nonblocking receive of matched │
│ │ message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ probe(comm[, source, tag, status]) │ Blocking test for a matched message. │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
├─────────────────────────────────────┼───────────────────────────────────────┤
│ recv([status]) │ Blocking receive of matched message. │
└─────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────┬─────────────┐
│ handle │ MPI handle. │
└────────┴─────────────┘
Methods Documentation
classmethod Iprobe(comm, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a matched message.
Parameters
• comm (Comm)
• source (int)
• tag (int)
• status (Status | None)
Return type
Self | None
Irecv(buf)
Nonblocking receive of matched message.
Parameters
buf (BufSpec)
Return type
Request
classmethod Probe(comm, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a matched message.
Parameters
• comm (Comm)
• source (int)
• tag (int)
• status (Status | None)
Return type
Self
Recv(buf, status=None)
Blocking receive of matched message.
Parameters
• buf (BufSpec)
• status (Status | None)
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
Message
free() Do nothing.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Message
classmethod iprobe(comm, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Nonblocking test for a matched message.
Parameters
• comm (Comm)
• source (int)
• tag (int)
• status (Status | None)
Return type
Self | None
irecv()
Nonblocking receive of matched message.
Return type
Request
classmethod probe(comm, source=ANY_SOURCE, tag=ANY_TAG, status=None)
Blocking test for a matched message.
Parameters
• comm (Comm)
• source (int)
• tag (int)
• status (Status | None)
Return type
Self
py2f()
Return type
int
recv(status=None)
Blocking receive of matched message.
Parameters
status (Status | None)
Return type
Any
Attributes Documentation
handle MPI handle.
mpi4py.MPI.Op
class mpi4py.MPI.Op
Bases: object
Reduction operation.
static __new__(cls, op=None)
Parameters
op (Op | None)
Return type
Self
Methods Summary
┌───────────────────────────────┬───────────────────────────────────────┐
│ Create(function[, commute]) │ Create a user-defined reduction │
│ │ operation. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Free() │ Free a user-defined reduction │
│ │ operation. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Is_commutative() │ Query reduction operations for their │
│ │ commutativity. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Reduce_local(inbuf, inoutbuf) │ Apply a reduction operation to local │
│ │ data. │
├───────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null or predefined. │
├───────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
└───────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────────────┬─────────────────────────────┐
│ handle │ MPI handle. │
├────────────────┼─────────────────────────────┤
│ is_commutative │ Is a commutative operation. │
├────────────────┼─────────────────────────────┤
│ is_predefined │ Is a predefined operation. │
└────────────────┴─────────────────────────────┘
Methods Documentation
classmethod Create(function, commute=False)
Create a user-defined reduction operation.
Parameters
• function (Callable[[Buffer, Buffer, Datatype], None])
• commute (bool)
Return type
Self
Free() Free a user-defined reduction operation.
Return type
None
Is_commutative()
Query reduction operations for their commutativity.
Return type
bool
Reduce_local(inbuf, inoutbuf)
Apply a reduction operation to local data.
Parameters
• inbuf (BufSpec)
• inoutbuf (BufSpec)
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
Op
free() Call Free if not null or predefined.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Op
py2f()
Return type
int
Attributes Documentation
handle MPI handle.
is_commutative
Is a commutative operation.
is_predefined
Is a predefined operation.
mpi4py.MPI.Pickle
class mpi4py.MPI.Pickle
Bases: object
Pickle/unpickle Python objects.
static __new__(cls, pickle=None)
Parameters
pickle (Pickle | None)
Return type
Self
Methods Summary
┌──────────────────────────┬───────────────────────────────────────┐
│ dumps(obj) │ Serialize object to pickle data │
│ │ stream. │
├──────────────────────────┼───────────────────────────────────────┤
│ dumps_oob(obj) │ Serialize object to pickle data │
│ │ stream and out-of-band buffers. │
├──────────────────────────┼───────────────────────────────────────┤
│ loads(data) │ Deserialize object from pickle data │
│ │ stream. │
├──────────────────────────┼───────────────────────────────────────┤
│ loads_oob(data, buffers) │ Deserialize object from pickle data │
│ │ stream and out-of-band buffers. │
└──────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌───────────┬────────────────────────┐
│ PROTOCOL │ Protocol version. │
├───────────┼────────────────────────┤
│ THRESHOLD │ Out-of-band threshold. │
└───────────┴────────────────────────┘
Methods Documentation
dumps(obj)
Serialize object to pickle data stream.
Parameters
obj (Any)
Return type
bytes
dumps_oob(obj)
Serialize object to pickle data stream and out-of-band buffers.
Parameters
obj (Any)
Return type
tuple[bytes, list[buffer]]
loads(data)
Deserialize object from pickle data stream.
Parameters
data (Buffer)
Return type
Any
loads_oob(data, buffers)
Deserialize object from pickle data stream and out-of-band buffers.
Parameters
• data (Buffer)
• buffers (Iterable[Buffer])
Return type
Any
Attributes Documentation
PROTOCOL
Protocol version.
THRESHOLD
Out-of-band threshold.
mpi4py.MPI.Prequest
class mpi4py.MPI.Prequest
Bases: Request
Persistent request handler.
static __new__(cls, request=None)
Parameters
request (Prequest | None)
Return type
Self
Methods Summary
┌─────────────────────────────┬───────────────────────────────────────┐
│ Parrived(partition) │ Test partial completion of a │
│ │ partitioned receive operation. │
├─────────────────────────────┼───────────────────────────────────────┤
│ Pready(partition) │ Mark a given partition as ready. │
├─────────────────────────────┼───────────────────────────────────────┤
│ Pready_list(partitions) │ Mark a sequence of partitions as │
│ │ ready. │
├─────────────────────────────┼───────────────────────────────────────┤
│ Pready_range(partition_low, │ Mark a range of partitions as ready. │
│ partition_high) │ │
├─────────────────────────────┼───────────────────────────────────────┤
│ Start() │ Initiate a communication with a │
│ │ persistent request. │
├─────────────────────────────┼───────────────────────────────────────┤
│ Startall(requests) │ Start a collection of persistent │
│ │ requests. │
└─────────────────────────────┴───────────────────────────────────────┘
Methods Documentation
Parrived(partition)
Test partial completion of a partitioned receive operation.
Parameters
partition (int)
Return type
bool
Pready(partition)
Mark a given partition as ready.
Parameters
partition (int)
Return type
None
Pready_list(partitions)
Mark a sequence of partitions as ready.
Parameters
partitions (Sequence[int])
Return type
None
Pready_range(partition_low, partition_high)
Mark a range of partitions as ready.
Parameters
• partition_low (int)
• partition_high (int)
Return type
None
Start()
Initiate a communication with a persistent request.
Return type
None
classmethod Startall(requests)
Start a collection of persistent requests.
Parameters
requests (list[Prequest])
Return type
None
mpi4py.MPI.Request
class mpi4py.MPI.Request
Bases: object
Request handler.
static __new__(cls, request=None)
Parameters
request (Request | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Cancel() │ Cancel a request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free() │ Free a communication request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_status([status]) │ Non-destructive test for the │
│ │ completion of a request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_status_all(requests[, statuses]) │ Non-destructive test for the │
│ │ completion of all requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_status_any(requests[, status]) │ Non-destructive test for the │
│ │ completion of any requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_status_some(requests[, statuses]) │ Non-destructive test for completion │
│ │ of some requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Test([status]) │ Test for the completion of a │
│ │ non-blocking operation. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Testall(requests[, statuses]) │ Test for completion of all previously │
│ │ initiated requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Testany(requests[, status]) │ Test for completion of any previously │
│ │ initiated request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Testsome(requests[, statuses]) │ Test for completion of some │
│ │ previously initiated requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Wait([status]) │ Wait for a non-blocking operation to │
│ │ complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Waitall(requests[, statuses]) │ Wait for all previously initiated │
│ │ requests to complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Waitany(requests[, status]) │ Wait for any previously initiated │
│ │ request to complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Waitsome(requests[, statuses]) │ Wait for some previously initiated │
│ │ requests to complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ cancel() │ Cancel a request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ get_status([status]) │ Non-destructive test for the │
│ │ completion of a request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ get_status_all(requests[, statuses]) │ Non-destructive test for the │
│ │ completion of all requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ get_status_any(requests[, status]) │ Non-destructive test for the │
│ │ completion of any requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ get_status_some(requests[, statuses]) │ Non-destructive test for completion │
│ │ of some requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ test([status]) │ Test for the completion of a │
│ │ non-blocking operation. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ testall(requests[, statuses]) │ Test for completion of all previously │
│ │ initiated requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ testany(requests[, status]) │ Test for completion of any previously │
│ │ initiated request. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ testsome(requests[, statuses]) │ Test for completion of some │
│ │ previously initiated requests. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ wait([status]) │ Wait for a non-blocking operation to │
│ │ complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ waitall(requests[, statuses]) │ Wait for all previously initiated │
│ │ requests to complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ waitany(requests[, status]) │ Wait for any previously initiated │
│ │ request to complete. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ waitsome(requests[, statuses]) │ Wait for some previously initiated │
│ │ requests to complete. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────┬─────────────┐
│ handle │ MPI handle. │
└────────┴─────────────┘
Methods Documentation
Cancel()
Cancel a request.
Return type
None
Free() Free a communication request.
Return type
None
Get_status(status=None)
Non-destructive test for the completion of a request.
Parameters
status (Status | None)
Return type
bool
classmethod Get_status_all(requests, statuses=None)
Non-destructive test for the completion of all requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
bool
classmethod Get_status_any(requests, status=None)
Non-destructive test for the completion of any requests.
Parameters
• requests (Sequence[Request])
• status (Status | None)
Return type
tuple[int, bool]
classmethod Get_status_some(requests, statuses=None)
Non-destructive test for completion of some requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
list[int] | None
Test(status=None)
Test for the completion of a non-blocking operation.
Parameters
status (Status | None)
Return type
bool
classmethod Testall(requests, statuses=None)
Test for completion of all previously initiated requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
bool
classmethod Testany(requests, status=None)
Test for completion of any previously initiated request.
Parameters
• requests (Sequence[Request])
• status (Status | None)
Return type
tuple[int, bool]
classmethod Testsome(requests, statuses=None)
Test for completion of some previously initiated requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
list[int] | None
Wait(status=None)
Wait for a non-blocking operation to complete.
Parameters
status (Status | None)
Return type
Literal[True]
classmethod Waitall(requests, statuses=None)
Wait for all previously initiated requests to complete.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
Literal[True]
classmethod Waitany(requests, status=None)
Wait for any previously initiated request to complete.
Parameters
• requests (Sequence[Request])
• status (Status | None)
Return type
int
classmethod Waitsome(requests, statuses=None)
Wait for some previously initiated requests to complete.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
list[int] | None
cancel()
Cancel a request.
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
Request
free() Call Free if not null.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Request
get_status(status=None)
Non-destructive test for the completion of a request.
Parameters
status (Status | None)
Return type
bool
classmethod get_status_all(requests, statuses=None)
Non-destructive test for the completion of all requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
bool
classmethod get_status_any(requests, status=None)
Non-destructive test for the completion of any requests.
Parameters
• requests (Sequence[Request])
• status (Status | None)
Return type
tuple[int, bool]
classmethod get_status_some(requests, statuses=None)
Non-destructive test for completion of some requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
list[int] | None
py2f()
Return type
int
test(status=None)
Test for the completion of a non-blocking operation.
Parameters
status (Status | None)
Return type
tuple[bool, Any | None]
classmethod testall(requests, statuses=None)
Test for completion of all previously initiated requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
tuple[bool, list[Any] | None]
classmethod testany(requests, status=None)
Test for completion of any previously initiated request.
Parameters
• requests (Sequence[Request])
• status (Status | None)
Return type
tuple[int, bool, Any | None]
classmethod testsome(requests, statuses=None)
Test for completion of some previously initiated requests.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
tuple[list[int] | None, list[Any] | None]
wait(status=None)
Wait for a non-blocking operation to complete.
Parameters
status (Status | None)
Return type
Any
classmethod waitall(requests, statuses=None)
Wait for all previously initiated requests to complete.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
list[Any]
classmethod waitany(requests, status=None)
Wait for any previously initiated request to complete.
Parameters
• requests (Sequence[Request])
• status (Status | None)
Return type
tuple[int, Any]
classmethod waitsome(requests, statuses=None)
Wait for some previously initiated requests to complete.
Parameters
• requests (Sequence[Request])
• statuses (list[Status] | None)
Return type
tuple[list[int] | None, list[Any] | None]
Attributes Documentation
handle MPI handle.
mpi4py.MPI.Session
class mpi4py.MPI.Session
Bases: object
Session context.
static __new__(cls, session=None)
Parameters
session (Session | None)
Return type
Self
Methods Summary
┌──────────────────────────────────┬───────────────────────────────────────┐
│ Attach_buffer(buf) │ Attach a user-provided buffer for │
│ │ sending in buffered mode. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Call_errhandler(errorcode) │ Call the error handler installed on a │
│ │ session. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Create_errhandler(errhandler_fn) │ Create a new error handler for │
│ │ sessions. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Create_group(pset_name) │ Create a new group from session and │
│ │ process set. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Detach_buffer() │ Remove an existing attached buffer. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Finalize() │ Finalize a session. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Flush_buffer() │ Block until all buffered messages │
│ │ have been transmitted. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Get_errhandler() │ Get the error handler for a session. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Get_info() │ Return the current hints for a │
│ │ session. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Get_nth_pset(n[, info]) │ Name of the n-th process set. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Get_num_psets([info]) │ Number of available process sets. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Get_pset_info(pset_name) │ Return the current hints for a │
│ │ session and process set. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Iflush_buffer() │ Nonblocking flush for buffered │
│ │ messages. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Init([info, errhandler]) │ Create a new session. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ Set_errhandler(errhandler) │ Set the error handler for a session. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├──────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Finalize if not null. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├──────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
└──────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────┬─────────────┐
│ handle │ MPI handle. │
└────────┴─────────────┘
Methods Documentation
Attach_buffer(buf)
Attach a user-provided buffer for sending in buffered mode.
Parameters
buf (Buffer | None)
Return type
None
Call_errhandler(errorcode)
Call the error handler installed on a session.
Parameters
errorcode (int)
Return type
None
classmethod Create_errhandler(errhandler_fn)
Create a new error handler for sessions.
Parameters
errhandler_fn (Callable[[Session, int], None])
Return type
Errhandler
Create_group(pset_name)
Create a new group from session and process set.
Parameters
pset_name (str)
Return type
Group
Detach_buffer()
Remove an existing attached buffer.
Return type
Buffer | None
Finalize()
Finalize a session.
Return type
None
Flush_buffer()
Block until all buffered messages have been transmitted.
Return type
None
Get_errhandler()
Get the error handler for a session.
Return type
Errhandler
Get_info()
Return the current hints for a session.
Return type
Info
Get_nth_pset(n, info=INFO_NULL)
Name of the n-th process set.
Parameters
• n (int)
• info (Info)
Return type
str
Get_num_psets(info=INFO_NULL)
Number of available process sets.
Parameters
info (Info)
Return type
int
Get_pset_info(pset_name)
Return the current hints for a session and process set.
Parameters
pset_name (str)
Return type
Info
Iflush_buffer()
Nonblocking flush for buffered messages.
Return type
Request
classmethod Init(info=INFO_NULL, errhandler=None)
Create a new session.
Parameters
• info (Info)
• errhandler (Errhandler | None)
Return type
Self
Set_errhandler(errhandler)
Set the error handler for a session.
Parameters
errhandler (Errhandler)
Return type
None
classmethod f2py(arg)
Parameters
arg (int)
Return type
Session
free() Call Finalize if not null.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Session
py2f()
Return type
int
Attributes Documentation
handle MPI handle.
mpi4py.MPI.Status
class mpi4py.MPI.Status
Bases: object
Status object.
static __new__(cls, status=None)
Parameters
status (Status | None)
Return type
Self
Methods Summary
┌───────────────────────────────┬───────────────────────────────────────┐
│ Get_count([datatype]) │ Get the number of top level elements. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Get_elements(datatype) │ Get the number of basic elements in a │
│ │ datatype. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Get_error() │ Get message error. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Get_source() │ Get message source. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Get_tag() │ Get message tag. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Is_cancelled() │ Test to see if a request was │
│ │ cancelled. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Set_cancelled(flag) │ Set the cancelled state associated │
│ │ with a status. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Set_elements(datatype, count) │ Set the number of elements in a │
│ │ status. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Set_error(error) │ Set message error. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Set_source(source) │ Set message source. │
├───────────────────────────────┼───────────────────────────────────────┤
│ Set_tag(tag) │ Set message tag. │
├───────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
└───────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌───────────┬──────────────────┐
│ cancelled │ Cancelled state. │
├───────────┼──────────────────┤
│ count │ Byte count. │
├───────────┼──────────────────┤
│ error │ Message error. │
├───────────┼──────────────────┤
│ source │ Message source. │
├───────────┼──────────────────┤
│ tag │ Message tag. │
└───────────┴──────────────────┘
Methods Documentation
Get_count(datatype=BYTE)
Get the number of top level elements.
Parameters
datatype (Datatype)
Return type
int
Get_elements(datatype)
Get the number of basic elements in a datatype.
Parameters
datatype (Datatype)
Return type
int
Get_error()
Get message error.
Return type
int
Get_source()
Get message source.
Return type
int
Get_tag()
Get message tag.
Return type
int
Is_cancelled()
Test to see if a request was cancelled.
Return type
bool
Set_cancelled(flag)
Set the cancelled state associated with a status.
NOTE:
This method should be used only when implementing query callback functions for
generalized requests.
Parameters
flag (bool)
Return type
None
Set_elements(datatype, count)
Set the number of elements in a status.
NOTE:
This method should be only used when implementing query callback functions for
generalized requests.
Parameters
• datatype (Datatype)
• count (int)
Return type
None
Set_error(error)
Set message error.
Parameters
error (int)
Return type
None
Set_source(source)
Set message source.
Parameters
source (int)
Return type
None
Set_tag(tag)
Set message tag.
Parameters
tag (int)
Return type
None
classmethod f2py(arg)
Parameters
arg (list[int])
Return type
Self
py2f()
Return type
list[int]
Attributes Documentation
cancelled
Cancelled state.
count Byte count.
error Message error.
source Message source.
tag Message tag.
mpi4py.MPI.Topocomm
class mpi4py.MPI.Topocomm
Bases: Intracomm
Topology intracommunicator.
static __new__(cls, comm=None)
Parameters
comm (Topocomm | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Ineighbor_allgather(sendbuf, recvbuf) │ Nonblocking Neighbor Gather to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ineighbor_allgatherv(sendbuf, │ Nonblocking Neighbor Gather to All │
│ recvbuf) │ Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ineighbor_alltoall(sendbuf, recvbuf) │ Nonblocking Neighbor All to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ineighbor_alltoallv(sendbuf, recvbuf) │ Nonblocking Neighbor All to All │
│ │ Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Ineighbor_alltoallw(sendbuf, recvbuf) │ Nonblocking Neighbor All to All │
│ │ General. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_allgather(sendbuf, recvbuf) │ Neighbor Gather to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_allgather_init(sendbuf, │ Persistent Neighbor Gather to All. │
│ recvbuf[, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_allgatherv(sendbuf, recvbuf) │ Neighbor Gather to All Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_allgatherv_init(sendbuf, │ Persistent Neighbor Gather to All │
│ recvbuf[, ...]) │ Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_alltoall(sendbuf, recvbuf) │ Neighbor All to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_alltoall_init(sendbuf, │ Persistent Neighbor All to All. │
│ recvbuf[, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_alltoallv(sendbuf, recvbuf) │ Neighbor All to All Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_alltoallv_init(sendbuf, │ Persistent Neighbor All to All │
│ recvbuf[, info]) │ Vector. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_alltoallw(sendbuf, recvbuf) │ Neighbor All to All General. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Neighbor_alltoallw_init(sendbuf, │ Persistent Neighbor All to All │
│ recvbuf[, info]) │ General. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ neighbor_allgather(sendobj) │ Neighbor Gather to All. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ neighbor_alltoall(sendobj) │ Neighbor All to All. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────────┬───────────────────────────────────────┐
│ degrees │ Number of incoming and outgoing │
│ │ neighbors. │
├────────────┼───────────────────────────────────────┤
│ indegree │ Number of incoming neighbors. │
├────────────┼───────────────────────────────────────┤
│ inedges │ Incoming neighbors. │
├────────────┼───────────────────────────────────────┤
│ inoutedges │ Incoming and outgoing neighbors. │
├────────────┼───────────────────────────────────────┤
│ outdegree │ Number of outgoing neighbors. │
├────────────┼───────────────────────────────────────┤
│ outedges │ Outgoing neighbors. │
└────────────┴───────────────────────────────────────┘
Methods Documentation
Ineighbor_allgather(sendbuf, recvbuf)
Nonblocking Neighbor Gather to All.
Parameters
• sendbuf (BufSpec)
• recvbuf (BufSpecB)
Return type
Request
Ineighbor_allgatherv(sendbuf, recvbuf)
Nonblocking Neighbor Gather to All Vector.
Parameters
• sendbuf (BufSpec)
• recvbuf (BufSpecV)
Return type
Request
Ineighbor_alltoall(sendbuf, recvbuf)
Nonblocking Neighbor All to All.
Parameters
• sendbuf (BufSpecB)
• recvbuf (BufSpecB)
Return type
Request
Ineighbor_alltoallv(sendbuf, recvbuf)
Nonblocking Neighbor All to All Vector.
Parameters
• sendbuf (BufSpecV)
• recvbuf (BufSpecV)
Return type
Request
Ineighbor_alltoallw(sendbuf, recvbuf)
Nonblocking Neighbor All to All General.
Parameters
• sendbuf (BufSpecW)
• recvbuf (BufSpecW)
Return type
Request
Neighbor_allgather(sendbuf, recvbuf)
Neighbor Gather to All.
Parameters
• sendbuf (BufSpec)
• recvbuf (BufSpecB)
Return type
None
Neighbor_allgather_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Neighbor Gather to All.
Parameters
• sendbuf (BufSpec)
• recvbuf (BufSpecB)
• info (Info)
Return type
Prequest
Neighbor_allgatherv(sendbuf, recvbuf)
Neighbor Gather to All Vector.
Parameters
• sendbuf (BufSpec)
• recvbuf (BufSpecV)
Return type
None
Neighbor_allgatherv_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Neighbor Gather to All Vector.
Parameters
• sendbuf (BufSpec)
• recvbuf (BufSpecV)
• info (Info)
Return type
Prequest
Neighbor_alltoall(sendbuf, recvbuf)
Neighbor All to All.
Parameters
• sendbuf (BufSpecB)
• recvbuf (BufSpecB)
Return type
None
Neighbor_alltoall_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Neighbor All to All.
Parameters
• sendbuf (BufSpecB)
• recvbuf (BufSpecB)
• info (Info)
Return type
Prequest
Neighbor_alltoallv(sendbuf, recvbuf)
Neighbor All to All Vector.
Parameters
• sendbuf (BufSpecV)
• recvbuf (BufSpecV)
Return type
None
Neighbor_alltoallv_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Neighbor All to All Vector.
Parameters
• sendbuf (BufSpecV)
• recvbuf (BufSpecV)
• info (Info)
Return type
Prequest
Neighbor_alltoallw(sendbuf, recvbuf)
Neighbor All to All General.
Parameters
• sendbuf (BufSpecW)
• recvbuf (BufSpecW)
Return type
None
Neighbor_alltoallw_init(sendbuf, recvbuf, info=INFO_NULL)
Persistent Neighbor All to All General.
Parameters
• sendbuf (BufSpecW)
• recvbuf (BufSpecW)
• info (Info)
Return type
Prequest
neighbor_allgather(sendobj)
Neighbor Gather to All.
Parameters
sendobj (Any)
Return type
list[Any]
neighbor_alltoall(sendobj)
Neighbor All to All.
Parameters
sendobj (list[Any])
Return type
list[Any]
Attributes Documentation
degrees
Number of incoming and outgoing neighbors.
indegree
Number of incoming neighbors.
inedges
Incoming neighbors.
inoutedges
Incoming and outgoing neighbors.
outdegree
Number of outgoing neighbors.
outedges
Outgoing neighbors.
mpi4py.MPI.Win
class mpi4py.MPI.Win
Bases: object
Remote memory access context.
static __new__(cls, win=None)
Parameters
win (Win | None)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Accumulate(origin, target_rank[, │ Accumulate data into the target │
│ target, op]) │ process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allocate(size[, disp_unit, info, │ Create an window object for one-sided │
│ comm]) │ communication. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Allocate_shared(size[, disp_unit, │ Create an window object for one-sided │
│ info, comm]) │ communication. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Attach(memory) │ Attach a local memory region. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Call_errhandler(errorcode) │ Call the error handler installed on a │
│ │ window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Compare_and_swap(origin, compare, │ Perform one-sided atomic │
│ result, ...) │ compare-and-swap. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Complete() │ Complete an RMA operation begun after │
│ │ an Start. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create(memory[, disp_unit, info, │ Create an window object for one-sided │
│ comm]) │ communication. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_dynamic([info, comm]) │ Create an window object for one-sided │
│ │ communication. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_errhandler(errhandler_fn) │ Create a new error handler for │
│ │ windows. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Create_keyval([copy_fn, delete_fn, │ Create a new attribute key for │
│ nopython]) │ windows. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Delete_attr(keyval) │ Delete attribute value associated │
│ │ with a key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Detach(memory) │ Detach a local memory region. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Fence([assertion]) │ Perform an MPI fence synchronization │
│ │ on a window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Fetch_and_op(origin, result, │ Perform one-sided read-modify-write. │
│ target_rank[, ...]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush(rank) │ Complete all outstanding RMA │
│ │ operations at a target. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush_all() │ Complete all outstanding RMA │
│ │ operations at all targets. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush_local(rank) │ Complete locally all outstanding RMA │
│ │ operations at a target. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush_local_all() │ Complete locally all outstanding RMA │
│ │ operations at all targets. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free() │ Free a window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free_keyval(keyval) │ Free an attribute key for windows. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get(origin, target_rank[, target]) │ Get data from a memory window on a │
│ │ remote process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_accumulate(origin, result, │ Fetch-and-accumulate data into the │
│ target_rank) │ target process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_attr(keyval) │ Retrieve attribute value by key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_errhandler() │ Get the error handler for a window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_group() │ Access the group of processes that │
│ │ created the window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_info() │ Return the current hints for a │
│ │ window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_name() │ Get the print name for this window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Lock(rank[, lock_type, assertion]) │ Begin an RMA access epoch at the │
│ │ target process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Lock_all([assertion]) │ Begin an RMA access epoch at all │
│ │ processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Post(group[, assertion]) │ Start an RMA exposure epoch. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Put(origin, target_rank[, target]) │ Put data into a memory window on a │
│ │ remote process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Raccumulate(origin, target_rank[, │ Fetch-and-accumulate data into the │
│ target, op]) │ target process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Rget(origin, target_rank[, target]) │ Get data from a memory window on a │
│ │ remote process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Rget_accumulate(origin, result, │ Accumulate data into the target │
│ target_rank) │ process using remote memory access. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Rput(origin, target_rank[, target]) │ Put data into a memory window on a │
│ │ remote process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_attr(keyval, attrval) │ Store attribute value associated with │
│ │ a key. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_errhandler(errhandler) │ Set the error handler for a window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_info(info) │ Set new values for the hints │
│ │ associated with a window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Set_name(name) │ Set the print name for this window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Shared_query(rank) │ Query the process-local address for │
│ │ remote memory segments. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Start(group[, assertion]) │ Start an RMA access epoch for MPI. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Sync() │ Synchronize public and private copies │
│ │ of the window. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Test() │ Test whether an RMA exposure epoch │
│ │ has completed. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Unlock(rank) │ Complete an RMA access epoch at the │
│ │ target process. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Unlock_all() │ Complete an RMA access epoch at all │
│ │ processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Wait() │ Complete an RMA exposure epoch begun │
│ │ with Post. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ f2py(arg) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ free() │ Call Free if not null. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromhandle(handle) │ Create object from MPI handle. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ py2f() │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ tomemory() │ Return window memory buffer. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌────────────┬────────────────┐
│ attrs │ Attributes. │
├────────────┼────────────────┤
│ flavor │ Create flavor. │
├────────────┼────────────────┤
│ group │ Group. │
├────────────┼────────────────┤
│ group_rank │ Group rank. │
├────────────┼────────────────┤
│ group_size │ Group size. │
├────────────┼────────────────┤
│ handle │ MPI handle. │
├────────────┼────────────────┤
│ info │ Info hints. │
├────────────┼────────────────┤
│ model │ Memory model. │
├────────────┼────────────────┤
│ name │ Print name. │
└────────────┴────────────────┘
Methods Documentation
Accumulate(origin, target_rank, target=None, op=SUM)
Accumulate data into the target process.
Parameters
• origin (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
• op (Op)
Return type
None
classmethod Allocate(size, disp_unit=1, info=INFO_NULL, comm=COMM_SELF)
Create an window object for one-sided communication.
Parameters
• size (int)
• disp_unit (int)
• info (Info)
• comm (Intracomm)
Return type
Self
classmethod Allocate_shared(size, disp_unit=1, info=INFO_NULL, comm=COMM_SELF)
Create an window object for one-sided communication.
Parameters
• size (int)
• disp_unit (int)
• info (Info)
• comm (Intracomm)
Return type
Self
Attach(memory)
Attach a local memory region.
Parameters
memory (Buffer)
Return type
None
Call_errhandler(errorcode)
Call the error handler installed on a window.
Parameters
errorcode (int)
Return type
None
Compare_and_swap(origin, compare, result, target_rank, target_disp=0)
Perform one-sided atomic compare-and-swap.
Parameters
• origin (BufSpec)
• compare (BufSpec)
• result (BufSpec)
• target_rank (int)
• target_disp (int)
Return type
None
Complete()
Complete an RMA operation begun after an Start.
Return type
None
classmethod Create(memory, disp_unit=1, info=INFO_NULL, comm=COMM_SELF)
Create an window object for one-sided communication.
Parameters
• memory (Buffer | Bottom)
• disp_unit (int)
• info (Info)
• comm (Intracomm)
Return type
Self
classmethod Create_dynamic(info=INFO_NULL, comm=COMM_SELF)
Create an window object for one-sided communication.
Parameters
• info (Info)
• comm (Intracomm)
Return type
Self
classmethod Create_errhandler(errhandler_fn)
Create a new error handler for windows.
Parameters
errhandler_fn (Callable[[Win, int], None])
Return type
Errhandler
classmethod Create_keyval(copy_fn=None, delete_fn=None, nopython=False)
Create a new attribute key for windows.
Parameters
• copy_fn (Callable[[Win, int, Any], Any] | None)
• delete_fn (Callable[[Win, int, Any], None] | None)
• nopython (bool)
Return type
int
Delete_attr(keyval)
Delete attribute value associated with a key.
Parameters
keyval (int)
Return type
None
Detach(memory)
Detach a local memory region.
Parameters
memory (Buffer)
Return type
None
Fence(assertion=0)
Perform an MPI fence synchronization on a window.
Parameters
assertion (int)
Return type
None
Fetch_and_op(origin, result, target_rank, target_disp=0, op=SUM)
Perform one-sided read-modify-write.
Parameters
• origin (BufSpec)
• result (BufSpec)
• target_rank (int)
• target_disp (int)
• op (Op)
Return type
None
Flush(rank)
Complete all outstanding RMA operations at a target.
Parameters
rank (int)
Return type
None
Flush_all()
Complete all outstanding RMA operations at all targets.
Return type
None
Flush_local(rank)
Complete locally all outstanding RMA operations at a target.
Parameters
rank (int)
Return type
None
Flush_local_all()
Complete locally all outstanding RMA operations at all targets.
Return type
None
Free() Free a window.
Return type
None
classmethod Free_keyval(keyval)
Free an attribute key for windows.
Parameters
keyval (int)
Return type
int
Get(origin, target_rank, target=None)
Get data from a memory window on a remote process.
Parameters
• origin (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
Return type
None
Get_accumulate(origin, result, target_rank, target=None, op=SUM)
Fetch-and-accumulate data into the target process.
Parameters
• origin (BufSpec)
• result (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
• op (Op)
Return type
None
Get_attr(keyval)
Retrieve attribute value by key.
Parameters
keyval (int)
Return type
int | Any | None
Get_errhandler()
Get the error handler for a window.
Return type
Errhandler
Get_group()
Access the group of processes that created the window.
Return type
Group
Get_info()
Return the current hints for a window.
Return type
Info
Get_name()
Get the print name for this window.
Return type
str
Lock(rank, lock_type=LOCK_EXCLUSIVE, assertion=0)
Begin an RMA access epoch at the target process.
Parameters
• rank (int)
• lock_type (int)
• assertion (int)
Return type
None
Lock_all(assertion=0)
Begin an RMA access epoch at all processes.
Parameters
assertion (int)
Return type
None
Post(group, assertion=0)
Start an RMA exposure epoch.
Parameters
• group (Group)
• assertion (int)
Return type
None
Put(origin, target_rank, target=None)
Put data into a memory window on a remote process.
Parameters
• origin (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
Return type
None
Raccumulate(origin, target_rank, target=None, op=SUM)
Fetch-and-accumulate data into the target process.
Parameters
• origin (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
• op (Op)
Return type
Request
Rget(origin, target_rank, target=None)
Get data from a memory window on a remote process.
Parameters
• origin (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
Return type
Request
Rget_accumulate(origin, result, target_rank, target=None, op=SUM)
Accumulate data into the target process using remote memory access.
Parameters
• origin (BufSpec)
• result (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
• op (Op)
Return type
Request
Rput(origin, target_rank, target=None)
Put data into a memory window on a remote process.
Parameters
• origin (BufSpec)
• target_rank (int)
• target (TargetSpec | None)
Return type
Request
Set_attr(keyval, attrval)
Store attribute value associated with a key.
Parameters
• keyval (int)
• attrval (Any)
Return type
None
Set_errhandler(errhandler)
Set the error handler for a window.
Parameters
errhandler (Errhandler)
Return type
None
Set_info(info)
Set new values for the hints associated with a window.
Parameters
info (Info)
Return type
None
Set_name(name)
Set the print name for this window.
Parameters
name (str)
Return type
None
Shared_query(rank)
Query the process-local address for remote memory segments.
Parameters
rank (int)
Return type
tuple[buffer, int]
Start(group, assertion=0)
Start an RMA access epoch for MPI.
Parameters
• group (Group)
• assertion (int)
Return type
None
Sync() Synchronize public and private copies of the window.
Return type
None
Test() Test whether an RMA exposure epoch has completed.
Return type
bool
Unlock(rank)
Complete an RMA access epoch at the target process.
Parameters
rank (int)
Return type
None
Unlock_all()
Complete an RMA access epoch at all processes.
Return type
None
Wait() Complete an RMA exposure epoch begun with Post.
Return type
Literal[True]
classmethod f2py(arg)
Parameters
arg (int)
Return type
Win
free() Call Free if not null.
Return type
None
classmethod fromhandle(handle)
Create object from MPI handle.
Parameters
handle (int)
Return type
Win
py2f()
Return type
int
tomemory()
Return window memory buffer.
Return type
buffer
Attributes Documentation
attrs Attributes.
flavor Create flavor.
group Group.
group_rank
Group rank.
group_size
Group size.
handle MPI handle.
info Info hints.
model Memory model.
name Print name.
mpi4py.MPI.buffer
class mpi4py.MPI.buffer
Bases: object
Buffer.
static __new__(cls, buf)
Parameters
buf (Buffer)
Return type
Self
Methods Summary
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ allocate(nbytes[, clear]) │ Buffer allocation. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ cast(format[, shape]) │ Cast to a memoryview with new format │
│ │ or shape. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ fromaddress(address, nbytes[, │ Buffer from address and size in │
│ readonly]) │ bytes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ frombuffer(obj[, readonly]) │ Buffer from buffer-like object. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ release() │ Release the underlying buffer exposed │
│ │ by the buffer object. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ tobytes([order]) │ Return the data in the buffer as a │
│ │ byte string. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ toreadonly() │ Return a readonly version of the │
│ │ buffer object. │
└───────────────────────────────────────┴───────────────────────────────────────┘
Attributes Summary
┌──────────┬──────────────────────────────────┐
│ address │ Buffer address. │
├──────────┼──────────────────────────────────┤
│ format │ Format of each element. │
├──────────┼──────────────────────────────────┤
│ itemsize │ Size (in bytes) of each element. │
├──────────┼──────────────────────────────────┤
│ nbytes │ Buffer size (in bytes). │
├──────────┼──────────────────────────────────┤
│ obj │ Object exposing buffer. │
├──────────┼──────────────────────────────────┤
│ readonly │ Buffer is read-only. │
└──────────┴──────────────────────────────────┘
Methods Documentation
static allocate(nbytes, clear=False)
Buffer allocation.
Parameters
• nbytes (int)
• clear (bool)
Return type
buffer
cast(format, shape=Ellipsis)
Cast to a memoryview with new format or shape.
Parameters
• format (str)
• shape (list[int] | tuple[int, ...])
Return type
memoryview
static fromaddress(address, nbytes, readonly=False)
Buffer from address and size in bytes.
Parameters
• address (int)
• nbytes (int)
• readonly (bool)
Return type
buffer
static frombuffer(obj, readonly=False)
Buffer from buffer-like object.
Parameters
• obj (Buffer)
• readonly (bool)
Return type
buffer
release()
Release the underlying buffer exposed by the buffer object.
Return type
None
tobytes(order=None)
Return the data in the buffer as a byte string.
Parameters
order (str | None)
Return type
bytes
toreadonly()
Return a readonly version of the buffer object.
Return type
buffer
Attributes Documentation
address
Buffer address.
format Format of each element.
itemsize
Size (in bytes) of each element.
nbytes Buffer size (in bytes).
obj Object exposing buffer.
readonly
Buffer is read-only.
mpi4py.MPI.memory
mpi4py.MPI.memory
alias of buffer
Exceptions
┌───────────┬──────────────────┐
│ Exception │ Exception class. │
└───────────┴──────────────────┘
mpi4py.MPI.Exception
exception mpi4py.MPI.Exception
Bases: RuntimeError
Exception class.
static __new__(cls, ierr=SUCCESS)
Parameters
ierr (int)
Return type
Self
Methods Summary
┌────────────────────┬───────────────┐
│ Get_error_class() │ Error class. │
├────────────────────┼───────────────┤
│ Get_error_code() │ Error code. │
├────────────────────┼───────────────┤
│ Get_error_string() │ Error string. │
└────────────────────┴───────────────┘
Attributes Summary
┌──────────────┬───────────────┐
│ error_class │ Error class. │
├──────────────┼───────────────┤
│ error_code │ Error code. │
├──────────────┼───────────────┤
│ error_string │ Error string. │
└──────────────┴───────────────┘
Methods Documentation
Get_error_class()
Error class.
Return type
int
Get_error_code()
Error code.
Return type
int
Get_error_string()
Error string.
Return type
str
Attributes Documentation
error_class
Error class.
error_code
Error code.
error_string
Error string.
Functions
┌───────────────────────────────────────┬───────────────────────────────────────┐
│ Add_error_class() │ Add an error class to the known error │
│ │ classes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Add_error_code(errorclass) │ Add an error code to an error class. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Add_error_string(errorcode, string) │ Associate an error string with an │
│ │ error class or error code. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Aint_add(base, disp) │ Return the sum of base address and │
│ │ displacement. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Aint_diff(addr1, addr2) │ Return the difference between │
│ │ absolute addresses. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Alloc_mem(size[, info]) │ Allocate memory for message passing │
│ │ and remote memory access. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Attach_buffer(buf) │ Attach a user-provided buffer for │
│ │ sending in buffered mode. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Close_port(port_name) │ Close a port. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Compute_dims(nnodes, dims) │ Return a balanced distribution of │
│ │ processes per coordinate direction. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Detach_buffer() │ Remove an existing attached buffer. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Finalize() │ Terminate the MPI execution │
│ │ environment. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Flush_buffer() │ Block until all buffered messages │
│ │ have been transmitted. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Free_mem(mem) │ Free memory allocated with Alloc_mem. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_address(location) │ Get the address of a location in │
│ │ memory. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_error_class(errorcode) │ Convert an error code into an error │
│ │ class. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_error_string(errorcode) │ Return the error string for a given │
│ │ error class or error code. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_hw_resource_info() │ Obtain information about the hardware │
│ │ platform of the calling processor. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_library_version() │ Obtain the version string of the MPI │
│ │ library. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_processor_name() │ Obtain the name of the calling │
│ │ processor. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Get_version() │ Obtain the version number of the MPI │
│ │ standard. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Iflush_buffer() │ Nonblocking flush for buffered │
│ │ messages. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Init() │ Initialize the MPI execution │
│ │ environment. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Init_thread([required]) │ Initialize the MPI execution │
│ │ environment. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Is_finalized() │ Indicate whether Finalize has │
│ │ completed. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Is_initialized() │ Indicate whether Init has been │
│ │ called. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Is_thread_main() │ Indicate whether this thread called │
│ │ Init or Init_thread. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Lookup_name(service_name[, info]) │ Lookup a port name given a service │
│ │ name. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Open_port([info]) │ Return an address used to connect │
│ │ group of processes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Pcontrol(level) │ Control profiling. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Publish_name(service_name, │ Publish a service name. │
│ port_name[, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Query_thread() │ Return the level of thread support │
│ │ provided by the MPI library. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Register_datarep(datarep, read_fn, │ Register user-defined data │
│ write_fn, ...) │ representations. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Remove_error_class(errorclass) │ Remove an error class from the known │
│ │ error classes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Remove_error_code(errorcode) │ Remove an error code from the known │
│ │ error codes. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Remove_error_string(errorcode) │ Remove error string association from │
│ │ error class or error code. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Unpublish_name(service_name, │ Unpublish a service name. │
│ port_name[, info]) │ │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Wtick() │ Return the resolution of Wtime. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ Wtime() │ Return an elapsed time on the calling │
│ │ processor. │
├───────────────────────────────────────┼───────────────────────────────────────┤
│ get_vendor() │ Information about the underlying MPI │
│ │ implementation. │
└───────────────────────────────────────┴───────────────────────────────────────┘
mpi4py.MPI.Add_error_class
mpi4py.MPI.Add_error_class()
Add an error class to the known error classes.
Return type
int
mpi4py.MPI.Add_error_code
mpi4py.MPI.Add_error_code(errorclass)
Add an error code to an error class.
Parameters
errorclass (int)
Return type
int
mpi4py.MPI.Add_error_string
mpi4py.MPI.Add_error_string(errorcode, string)
Associate an error string with an error class or error code.
Parameters
• errorcode (int)
• string (str)
Return type
None
mpi4py.MPI.Aint_add
mpi4py.MPI.Aint_add(base, disp)
Return the sum of base address and displacement.
Parameters
• base (int)
• disp (int)
Return type
int
mpi4py.MPI.Aint_diff
mpi4py.MPI.Aint_diff(addr1, addr2)
Return the difference between absolute addresses.
Parameters
• addr1 (int)
• addr2 (int)
Return type
int
mpi4py.MPI.Alloc_mem
mpi4py.MPI.Alloc_mem(size, info=INFO_NULL)
Allocate memory for message passing and remote memory access.
Parameters
• size (int)
• info (Info)
Return type
buffer
mpi4py.MPI.Attach_buffer
mpi4py.MPI.Attach_buffer(buf)
Attach a user-provided buffer for sending in buffered mode.
Parameters
buf (Buffer | None)
Return type
None
mpi4py.MPI.Close_port
mpi4py.MPI.Close_port(port_name)
Close a port.
Parameters
port_name (str)
Return type
None
mpi4py.MPI.Compute_dims
mpi4py.MPI.Compute_dims(nnodes, dims)
Return a balanced distribution of processes per coordinate direction.
Parameters
• nnodes (int)
• dims (int | Sequence[int])
Return type
list[int]
mpi4py.MPI.Detach_buffer
mpi4py.MPI.Detach_buffer()
Remove an existing attached buffer.
Return type
Buffer | None
mpi4py.MPI.Finalize
mpi4py.MPI.Finalize()
Terminate the MPI execution environment.
Return type
None
mpi4py.MPI.Flush_buffer
mpi4py.MPI.Flush_buffer()
Block until all buffered messages have been transmitted.
Return type
None
mpi4py.MPI.Free_mem
mpi4py.MPI.Free_mem(mem)
Free memory allocated with Alloc_mem.
Parameters
mem (buffer)
Return type
None
mpi4py.MPI.Get_address
mpi4py.MPI.Get_address(location)
Get the address of a location in memory.
Parameters
location (Buffer | Bottom)
Return type
int
mpi4py.MPI.Get_error_class
mpi4py.MPI.Get_error_class(errorcode)
Convert an error code into an error class.
Parameters
errorcode (int)
Return type
int
mpi4py.MPI.Get_error_string
mpi4py.MPI.Get_error_string(errorcode)
Return the error string for a given error class or error code.
Parameters
errorcode (int)
Return type
str
mpi4py.MPI.Get_hw_resource_info
mpi4py.MPI.Get_hw_resource_info()
Obtain information about the hardware platform of the calling processor.
Return type
Info
mpi4py.MPI.Get_library_version
mpi4py.MPI.Get_library_version()
Obtain the version string of the MPI library.
Return type
str
mpi4py.MPI.Get_processor_name
mpi4py.MPI.Get_processor_name()
Obtain the name of the calling processor.
Return type
str
mpi4py.MPI.Get_version
mpi4py.MPI.Get_version()
Obtain the version number of the MPI standard.
Return type
tuple[int, int]
mpi4py.MPI.Iflush_buffer
mpi4py.MPI.Iflush_buffer()
Nonblocking flush for buffered messages.
Return type
Request
mpi4py.MPI.Init
mpi4py.MPI.Init()
Initialize the MPI execution environment.
Return type
None
mpi4py.MPI.Init_thread
mpi4py.MPI.Init_thread(required=THREAD_MULTIPLE)
Initialize the MPI execution environment.
Parameters
required (int)
Return type
int
mpi4py.MPI.Is_finalized
mpi4py.MPI.Is_finalized()
Indicate whether Finalize has completed.
Return type
bool
mpi4py.MPI.Is_initialized
mpi4py.MPI.Is_initialized()
Indicate whether Init has been called.
Return type
bool
mpi4py.MPI.Is_thread_main
mpi4py.MPI.Is_thread_main()
Indicate whether this thread called Init or Init_thread.
Return type
bool
mpi4py.MPI.Lookup_name
mpi4py.MPI.Lookup_name(service_name, info=INFO_NULL)
Lookup a port name given a service name.
Parameters
• service_name (str)
• info (Info)
Return type
str
mpi4py.MPI.Open_port
mpi4py.MPI.Open_port(info=INFO_NULL)
Return an address used to connect group of processes.
Parameters
info (Info)
Return type
str
mpi4py.MPI.Pcontrol
mpi4py.MPI.Pcontrol(level)
Control profiling.
Parameters
level (int)
Return type
None
mpi4py.MPI.Publish_name
mpi4py.MPI.Publish_name(service_name, port_name, info=INFO_NULL)
Publish a service name.
Parameters
• service_name (str)
• port_name (str)
• info (Info)
Return type
None
mpi4py.MPI.Query_thread
mpi4py.MPI.Query_thread()
Return the level of thread support provided by the MPI library.
Return type
int
mpi4py.MPI.Register_datarep
mpi4py.MPI.Register_datarep(datarep, read_fn, write_fn, extent_fn)
Register user-defined data representations.
Parameters
• datarep (str)
• read_fn (Callable[[Buffer, Datatype, int, Buffer, int], None])
• write_fn (Callable[[Buffer, Datatype, int, Buffer, int], None])
• extent_fn (Callable[[Datatype], int])
Return type
None
mpi4py.MPI.Remove_error_class
mpi4py.MPI.Remove_error_class(errorclass)
Remove an error class from the known error classes.
Parameters
errorclass (int)
Return type
None
mpi4py.MPI.Remove_error_code
mpi4py.MPI.Remove_error_code(errorcode)
Remove an error code from the known error codes.
Parameters
errorcode (int)
Return type
None
mpi4py.MPI.Remove_error_string
mpi4py.MPI.Remove_error_string(errorcode)
Remove error string association from error class or error code.
Parameters
errorcode (int)
Return type
None
mpi4py.MPI.Unpublish_name
mpi4py.MPI.Unpublish_name(service_name, port_name, info=INFO_NULL)
Unpublish a service name.
Parameters
• service_name (str)
• port_name (str)
• info (Info)
Return type
None
mpi4py.MPI.Wtick
mpi4py.MPI.Wtick()
Return the resolution of Wtime.
Return type
float
mpi4py.MPI.Wtime
mpi4py.MPI.Wtime()
Return an elapsed time on the calling processor.
Return type
float
mpi4py.MPI.get_vendor
mpi4py.MPI.get_vendor()
Information about the underlying MPI implementation.
Returns
• string with the name of the MPI implementation.
• integer 3-tuple version number (major, minor, micro).
Return type
tuple[str, tuple[int, int, int]]
Attributes
┌────────────────────────────┬───────────────────────────────────────┐
│ UNDEFINED │ Constant UNDEFINED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ANY_SOURCE │ Constant ANY_SOURCE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ANY_TAG │ Constant ANY_TAG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ PROC_NULL │ Constant PROC_NULL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ROOT │ Constant ROOT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ BOTTOM │ Constant BOTTOM of type BottomType │
├────────────────────────────┼───────────────────────────────────────┤
│ IN_PLACE │ Constant IN_PLACE of type InPlaceType │
├────────────────────────────┼───────────────────────────────────────┤
│ KEYVAL_INVALID │ Constant KEYVAL_INVALID of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ TAG_UB │ Constant TAG_UB of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ IO │ Constant IO of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WTIME_IS_GLOBAL │ Constant WTIME_IS_GLOBAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ UNIVERSE_SIZE │ Constant UNIVERSE_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ APPNUM │ Constant APPNUM of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ LASTUSEDCODE │ Constant LASTUSEDCODE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_BASE │ Constant WIN_BASE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_SIZE │ Constant WIN_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_DISP_UNIT │ Constant WIN_DISP_UNIT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_CREATE_FLAVOR │ Constant WIN_CREATE_FLAVOR of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR │ Constant WIN_FLAVOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_MODEL │ Constant WIN_MODEL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SUCCESS │ Constant SUCCESS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_LASTCODE │ Constant ERR_LASTCODE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TYPE │ Constant ERR_TYPE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_REQUEST │ Constant ERR_REQUEST of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_OP │ Constant ERR_OP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_GROUP │ Constant ERR_GROUP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO │ Constant ERR_INFO of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ERRHANDLER │ Constant ERR_ERRHANDLER of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SESSION │ Constant ERR_SESSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_COMM │ Constant ERR_COMM of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_WIN │ Constant ERR_WIN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_FILE │ Constant ERR_FILE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_BUFFER │ Constant ERR_BUFFER of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_COUNT │ Constant ERR_COUNT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TAG │ Constant ERR_TAG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RANK │ Constant ERR_RANK of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ROOT │ Constant ERR_ROOT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TRUNCATE │ Constant ERR_TRUNCATE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_IN_STATUS │ Constant ERR_IN_STATUS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PENDING │ Constant ERR_PENDING of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_TOPOLOGY │ Constant ERR_TOPOLOGY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_DIMS │ Constant ERR_DIMS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ARG │ Constant ERR_ARG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_OTHER │ Constant ERR_OTHER of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_UNKNOWN │ Constant ERR_UNKNOWN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INTERN │ Constant ERR_INTERN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_KEYVAL │ Constant ERR_KEYVAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NO_MEM │ Constant ERR_NO_MEM of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO_KEY │ Constant ERR_INFO_KEY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO_VALUE │ Constant ERR_INFO_VALUE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_INFO_NOKEY │ Constant ERR_INFO_NOKEY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SPAWN │ Constant ERR_SPAWN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PORT │ Constant ERR_PORT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SERVICE │ Constant ERR_SERVICE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NAME │ Constant ERR_NAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PROC_ABORTED │ Constant ERR_PROC_ABORTED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_BASE │ Constant ERR_BASE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_SIZE │ Constant ERR_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_DISP │ Constant ERR_DISP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ASSERT │ Constant ERR_ASSERT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_LOCKTYPE │ Constant ERR_LOCKTYPE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_CONFLICT │ Constant ERR_RMA_CONFLICT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_SYNC │ Constant ERR_RMA_SYNC of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_RANGE │ Constant ERR_RMA_RANGE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_ATTACH │ Constant ERR_RMA_ATTACH of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_SHARED │ Constant ERR_RMA_SHARED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_RMA_FLAVOR │ Constant ERR_RMA_FLAVOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_BAD_FILE │ Constant ERR_BAD_FILE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NO_SUCH_FILE │ Constant ERR_NO_SUCH_FILE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_FILE_EXISTS │ Constant ERR_FILE_EXISTS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_FILE_IN_USE │ Constant ERR_FILE_IN_USE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_AMODE │ Constant ERR_AMODE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_ACCESS │ Constant ERR_ACCESS of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_READ_ONLY │ Constant ERR_READ_ONLY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NO_SPACE │ Constant ERR_NO_SPACE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_QUOTA │ Constant ERR_QUOTA of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_NOT_SAME │ Constant ERR_NOT_SAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_IO │ Constant ERR_IO of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_UNSUPPORTED_OPERATION │ Constant ERR_UNSUPPORTED_OPERATION of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_UNSUPPORTED_DATAREP │ Constant ERR_UNSUPPORTED_DATAREP of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_CONVERSION │ Constant ERR_CONVERSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_DUP_DATAREP │ Constant ERR_DUP_DATAREP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_VALUE_TOO_LARGE │ Constant ERR_VALUE_TOO_LARGE of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_REVOKED │ Constant ERR_REVOKED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PROC_FAILED │ Constant ERR_PROC_FAILED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ERR_PROC_FAILED_PENDING │ Constant ERR_PROC_FAILED_PENDING of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ORDER_C │ Constant ORDER_C of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ORDER_FORTRAN │ Constant ORDER_FORTRAN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ ORDER_F │ Constant ORDER_F of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ TYPECLASS_INTEGER │ Constant TYPECLASS_INTEGER of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ TYPECLASS_REAL │ Constant TYPECLASS_REAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ TYPECLASS_COMPLEX │ Constant TYPECLASS_COMPLEX of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_NONE │ Constant DISTRIBUTE_NONE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_BLOCK │ Constant DISTRIBUTE_BLOCK of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_CYCLIC │ Constant DISTRIBUTE_CYCLIC of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISTRIBUTE_DFLT_DARG │ Constant DISTRIBUTE_DFLT_DARG of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_NAMED │ Constant COMBINER_NAMED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_DUP │ Constant COMBINER_DUP of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_CONTIGUOUS │ Constant COMBINER_CONTIGUOUS of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_VECTOR │ Constant COMBINER_VECTOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_HVECTOR │ Constant COMBINER_HVECTOR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_INDEXED │ Constant COMBINER_INDEXED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_HINDEXED │ Constant COMBINER_HINDEXED of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_INDEXED_BLOCK │ Constant COMBINER_INDEXED_BLOCK of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_HINDEXED_BLOCK │ Constant COMBINER_HINDEXED_BLOCK of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_STRUCT │ Constant COMBINER_STRUCT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_SUBARRAY │ Constant COMBINER_SUBARRAY of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_DARRAY │ Constant COMBINER_DARRAY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_RESIZED │ Constant COMBINER_RESIZED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_VALUE_INDEX │ Constant COMBINER_VALUE_INDEX of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_F90_INTEGER │ Constant COMBINER_F90_INTEGER of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_F90_REAL │ Constant COMBINER_F90_REAL of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMBINER_F90_COMPLEX │ Constant COMBINER_F90_COMPLEX of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ F_SOURCE │ Constant F_SOURCE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ F_TAG │ Constant F_TAG of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ F_ERROR │ Constant F_ERROR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ F_STATUS_SIZE │ Constant F_STATUS_SIZE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ IDENT │ Constant IDENT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ CONGRUENT │ Constant CONGRUENT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SIMILAR │ Constant SIMILAR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ UNEQUAL │ Constant UNEQUAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ CART │ Constant CART of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ GRAPH │ Constant GRAPH of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DIST_GRAPH │ Constant DIST_GRAPH of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ UNWEIGHTED │ Constant UNWEIGHTED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WEIGHTS_EMPTY │ Constant WEIGHTS_EMPTY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_TYPE_SHARED │ Constant COMM_TYPE_SHARED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_TYPE_HW_GUIDED │ Constant COMM_TYPE_HW_GUIDED of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_TYPE_HW_UNGUIDED │ Constant COMM_TYPE_HW_UNGUIDED of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_TYPE_RESOURCE_GUIDED │ Constant COMM_TYPE_RESOURCE_GUIDED of │
│ │ type int │
├────────────────────────────┼───────────────────────────────────────┤
│ BSEND_OVERHEAD │ Constant BSEND_OVERHEAD of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ BUFFER_AUTOMATIC │ Constant BUFFER_AUTOMATIC of type │
│ │ BufferAutomaticType │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_CREATE │ Constant WIN_FLAVOR_CREATE of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_ALLOCATE │ Constant WIN_FLAVOR_ALLOCATE of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_DYNAMIC │ Constant WIN_FLAVOR_DYNAMIC of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_FLAVOR_SHARED │ Constant WIN_FLAVOR_SHARED of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_SEPARATE │ Constant WIN_SEPARATE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_UNIFIED │ Constant WIN_UNIFIED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOCHECK │ Constant MODE_NOCHECK of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOSTORE │ Constant MODE_NOSTORE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOPUT │ Constant MODE_NOPUT of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOPRECEDE │ Constant MODE_NOPRECEDE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_NOSUCCEED │ Constant MODE_NOSUCCEED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ LOCK_EXCLUSIVE │ Constant LOCK_EXCLUSIVE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ LOCK_SHARED │ Constant LOCK_SHARED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_RDONLY │ Constant MODE_RDONLY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_WRONLY │ Constant MODE_WRONLY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_RDWR │ Constant MODE_RDWR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_CREATE │ Constant MODE_CREATE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_EXCL │ Constant MODE_EXCL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_DELETE_ON_CLOSE │ Constant MODE_DELETE_ON_CLOSE of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_UNIQUE_OPEN │ Constant MODE_UNIQUE_OPEN of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_SEQUENTIAL │ Constant MODE_SEQUENTIAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MODE_APPEND │ Constant MODE_APPEND of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SEEK_SET │ Constant SEEK_SET of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SEEK_CUR │ Constant SEEK_CUR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SEEK_END │ Constant SEEK_END of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISPLACEMENT_CURRENT │ Constant DISPLACEMENT_CURRENT of type │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DISP_CUR │ Constant DISP_CUR of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_SINGLE │ Constant THREAD_SINGLE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_FUNNELED │ Constant THREAD_FUNNELED of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_SERIALIZED │ Constant THREAD_SERIALIZED of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ THREAD_MULTIPLE │ Constant THREAD_MULTIPLE of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ VERSION │ Constant VERSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ SUBVERSION │ Constant SUBVERSION of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_PROCESSOR_NAME │ Constant MAX_PROCESSOR_NAME of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_ERROR_STRING │ Constant MAX_ERROR_STRING of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_PORT_NAME │ Constant MAX_PORT_NAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_INFO_KEY │ Constant MAX_INFO_KEY of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_INFO_VAL │ Constant MAX_INFO_VAL of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_OBJECT_NAME │ Constant MAX_OBJECT_NAME of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_DATAREP_STRING │ Constant MAX_DATAREP_STRING of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_LIBRARY_VERSION_STRING │ Constant MAX_LIBRARY_VERSION_STRING │
│ │ of type int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_PSET_NAME_LEN │ Constant MAX_PSET_NAME_LEN of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX_STRINGTAG_LEN │ Constant MAX_STRINGTAG_LEN of type ‐ │
│ │ int │
├────────────────────────────┼───────────────────────────────────────┤
│ DATATYPE_NULL │ Object DATATYPE_NULL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ PACKED │ Object PACKED of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ BYTE │ Object BYTE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ AINT │ Object AINT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ OFFSET │ Object OFFSET of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COUNT │ Object COUNT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CHAR │ Object CHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ WCHAR │ Object WCHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_CHAR │ Object SIGNED_CHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SHORT │ Object SHORT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT │ Object INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG │ Object LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_LONG │ Object LONG_LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_CHAR │ Object UNSIGNED_CHAR of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_SHORT │ Object UNSIGNED_SHORT of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED │ Object UNSIGNED of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_LONG │ Object UNSIGNED_LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_LONG_LONG │ Object UNSIGNED_LONG_LONG of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ FLOAT │ Object FLOAT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE │ Object DOUBLE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_DOUBLE │ Object LONG_DOUBLE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_BOOL │ Object C_BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT8_T │ Object INT8_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT16_T │ Object INT16_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT32_T │ Object INT32_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT64_T │ Object INT64_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT8_T │ Object UINT8_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT16_T │ Object UINT16_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT32_T │ Object UINT32_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UINT64_T │ Object UINT64_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_COMPLEX │ Object C_COMPLEX of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_FLOAT_COMPLEX │ Object C_FLOAT_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_DOUBLE_COMPLEX │ Object C_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ C_LONG_DOUBLE_COMPLEX │ Object C_LONG_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_BOOL │ Object CXX_BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_FLOAT_COMPLEX │ Object CXX_FLOAT_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_DOUBLE_COMPLEX │ Object CXX_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CXX_LONG_DOUBLE_COMPLEX │ Object CXX_LONG_DOUBLE_COMPLEX of │
│ │ type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SHORT_INT │ Object SHORT_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INT_INT │ Object INT_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ TWOINT │ Object TWOINT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_INT │ Object LONG_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ FLOAT_INT │ Object FLOAT_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE_INT │ Object DOUBLE_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LONG_DOUBLE_INT │ Object LONG_DOUBLE_INT of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ CHARACTER │ Object CHARACTER of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL │ Object LOGICAL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER │ Object INTEGER of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL │ Object REAL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE_PRECISION │ Object DOUBLE_PRECISION of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX │ Object COMPLEX of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ DOUBLE_COMPLEX │ Object DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL1 │ Object LOGICAL1 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL2 │ Object LOGICAL2 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL4 │ Object LOGICAL4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ LOGICAL8 │ Object LOGICAL8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER1 │ Object INTEGER1 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER2 │ Object INTEGER2 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER4 │ Object INTEGER4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER8 │ Object INTEGER8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ INTEGER16 │ Object INTEGER16 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL2 │ Object REAL2 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL4 │ Object REAL4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL8 │ Object REAL8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REAL16 │ Object REAL16 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX4 │ Object COMPLEX4 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX8 │ Object COMPLEX8 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX16 │ Object COMPLEX16 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ COMPLEX32 │ Object COMPLEX32 of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ UNSIGNED_INT │ Object UNSIGNED_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_SHORT │ Object SIGNED_SHORT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_INT │ Object SIGNED_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_LONG │ Object SIGNED_LONG of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SIGNED_LONG_LONG │ Object SIGNED_LONG_LONG of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ BOOL │ Object BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT8_T │ Object SINT8_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT16_T │ Object SINT16_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT32_T │ Object SINT32_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ SINT64_T │ Object SINT64_T of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_BOOL │ Object F_BOOL of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_INT │ Object F_INT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_FLOAT │ Object F_FLOAT of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_DOUBLE │ Object F_DOUBLE of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_COMPLEX │ Object F_COMPLEX of type Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_FLOAT_COMPLEX │ Object F_FLOAT_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ F_DOUBLE_COMPLEX │ Object F_DOUBLE_COMPLEX of type │
│ │ Datatype │
├────────────────────────────┼───────────────────────────────────────┤
│ REQUEST_NULL │ Object REQUEST_NULL of type Request │
├────────────────────────────┼───────────────────────────────────────┤
│ MESSAGE_NULL │ Object MESSAGE_NULL of type Message │
├────────────────────────────┼───────────────────────────────────────┤
│ MESSAGE_NO_PROC │ Object MESSAGE_NO_PROC of type │
│ │ Message │
├────────────────────────────┼───────────────────────────────────────┤
│ OP_NULL │ Object OP_NULL of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MAX │ Object MAX of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MIN │ Object MIN of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ SUM │ Object SUM of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ PROD │ Object PROD of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ LAND │ Object LAND of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ BAND │ Object BAND of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ LOR │ Object LOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ BOR │ Object BOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ LXOR │ Object LXOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ BXOR │ Object BXOR of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MAXLOC │ Object MAXLOC of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ MINLOC │ Object MINLOC of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ REPLACE │ Object REPLACE of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ NO_OP │ Object NO_OP of type Op │
├────────────────────────────┼───────────────────────────────────────┤
│ GROUP_NULL │ Object GROUP_NULL of type Group │
├────────────────────────────┼───────────────────────────────────────┤
│ GROUP_EMPTY │ Object GROUP_EMPTY of type Group │
├────────────────────────────┼───────────────────────────────────────┤
│ INFO_NULL │ Object INFO_NULL of type Info │
├────────────────────────────┼───────────────────────────────────────┤
│ INFO_ENV │ Object INFO_ENV of type Info │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRHANDLER_NULL │ Object ERRHANDLER_NULL of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRORS_RETURN │ Object ERRORS_RETURN of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRORS_ABORT │ Object ERRORS_ABORT of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ ERRORS_ARE_FATAL │ Object ERRORS_ARE_FATAL of type │
│ │ Errhandler │
├────────────────────────────┼───────────────────────────────────────┤
│ SESSION_NULL │ Object SESSION_NULL of type Session │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_NULL │ Object COMM_NULL of type Comm │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_SELF │ Object COMM_SELF of type Intracomm │
├────────────────────────────┼───────────────────────────────────────┤
│ COMM_WORLD │ Object COMM_WORLD of type Intracomm │
├────────────────────────────┼───────────────────────────────────────┤
│ WIN_NULL │ Object WIN_NULL of type Win │
├────────────────────────────┼───────────────────────────────────────┤
│ FILE_NULL │ Object FILE_NULL of type File │
├────────────────────────────┼───────────────────────────────────────┤
│ pickle │ Object pickle of type Pickle │
└────────────────────────────┴───────────────────────────────────────┘
mpi4py.MPI.UNDEFINED
mpi4py.MPI.UNDEFINED: int = UNDEFINED
Constant UNDEFINED of type int
mpi4py.MPI.ANY_SOURCE
mpi4py.MPI.ANY_SOURCE: int = ANY_SOURCE
Constant ANY_SOURCE of type int
mpi4py.MPI.ANY_TAG
mpi4py.MPI.ANY_TAG: int = ANY_TAG
Constant ANY_TAG of type int
mpi4py.MPI.PROC_NULL
mpi4py.MPI.PROC_NULL: int = PROC_NULL
Constant PROC_NULL of type int
mpi4py.MPI.ROOT
mpi4py.MPI.ROOT: int = ROOT
Constant ROOT of type int
mpi4py.MPI.BOTTOM
mpi4py.MPI.BOTTOM: BottomType = BOTTOM
Constant BOTTOM of type BottomType
mpi4py.MPI.IN_PLACE
mpi4py.MPI.IN_PLACE: InPlaceType = IN_PLACE
Constant IN_PLACE of type InPlaceType
mpi4py.MPI.KEYVAL_INVALID
mpi4py.MPI.KEYVAL_INVALID: int = KEYVAL_INVALID
Constant KEYVAL_INVALID of type int
mpi4py.MPI.TAG_UB
mpi4py.MPI.TAG_UB: int = TAG_UB
Constant TAG_UB of type int
mpi4py.MPI.IO
mpi4py.MPI.IO: int = IO
Constant IO of type int
mpi4py.MPI.WTIME_IS_GLOBAL
mpi4py.MPI.WTIME_IS_GLOBAL: int = WTIME_IS_GLOBAL
Constant WTIME_IS_GLOBAL of type int
mpi4py.MPI.UNIVERSE_SIZE
mpi4py.MPI.UNIVERSE_SIZE: int = UNIVERSE_SIZE
Constant UNIVERSE_SIZE of type int
mpi4py.MPI.APPNUM
mpi4py.MPI.APPNUM: int = APPNUM
Constant APPNUM of type int
mpi4py.MPI.LASTUSEDCODE
mpi4py.MPI.LASTUSEDCODE: int = LASTUSEDCODE
Constant LASTUSEDCODE of type int
mpi4py.MPI.WIN_BASE
mpi4py.MPI.WIN_BASE: int = WIN_BASE
Constant WIN_BASE of type int
mpi4py.MPI.WIN_SIZE
mpi4py.MPI.WIN_SIZE: int = WIN_SIZE
Constant WIN_SIZE of type int
mpi4py.MPI.WIN_DISP_UNIT
mpi4py.MPI.WIN_DISP_UNIT: int = WIN_DISP_UNIT
Constant WIN_DISP_UNIT of type int
mpi4py.MPI.WIN_CREATE_FLAVOR
mpi4py.MPI.WIN_CREATE_FLAVOR: int = WIN_CREATE_FLAVOR
Constant WIN_CREATE_FLAVOR of type int
mpi4py.MPI.WIN_FLAVOR
mpi4py.MPI.WIN_FLAVOR: int = WIN_FLAVOR
Constant WIN_FLAVOR of type int
mpi4py.MPI.WIN_MODEL
mpi4py.MPI.WIN_MODEL: int = WIN_MODEL
Constant WIN_MODEL of type int
mpi4py.MPI.SUCCESS
mpi4py.MPI.SUCCESS: int = SUCCESS
Constant SUCCESS of type int
mpi4py.MPI.ERR_LASTCODE
mpi4py.MPI.ERR_LASTCODE: int = ERR_LASTCODE
Constant ERR_LASTCODE of type int
mpi4py.MPI.ERR_TYPE
mpi4py.MPI.ERR_TYPE: int = ERR_TYPE
Constant ERR_TYPE of type int
mpi4py.MPI.ERR_REQUEST
mpi4py.MPI.ERR_REQUEST: int = ERR_REQUEST
Constant ERR_REQUEST of type int
mpi4py.MPI.ERR_OP
mpi4py.MPI.ERR_OP: int = ERR_OP
Constant ERR_OP of type int
mpi4py.MPI.ERR_GROUP
mpi4py.MPI.ERR_GROUP: int = ERR_GROUP
Constant ERR_GROUP of type int
mpi4py.MPI.ERR_INFO
mpi4py.MPI.ERR_INFO: int = ERR_INFO
Constant ERR_INFO of type int
mpi4py.MPI.ERR_ERRHANDLER
mpi4py.MPI.ERR_ERRHANDLER: int = ERR_ERRHANDLER
Constant ERR_ERRHANDLER of type int
mpi4py.MPI.ERR_SESSION
mpi4py.MPI.ERR_SESSION: int = ERR_SESSION
Constant ERR_SESSION of type int
mpi4py.MPI.ERR_COMM
mpi4py.MPI.ERR_COMM: int = ERR_COMM
Constant ERR_COMM of type int
mpi4py.MPI.ERR_WIN
mpi4py.MPI.ERR_WIN: int = ERR_WIN
Constant ERR_WIN of type int
mpi4py.MPI.ERR_FILE
mpi4py.MPI.ERR_FILE: int = ERR_FILE
Constant ERR_FILE of type int
mpi4py.MPI.ERR_BUFFER
mpi4py.MPI.ERR_BUFFER: int = ERR_BUFFER
Constant ERR_BUFFER of type int
mpi4py.MPI.ERR_COUNT
mpi4py.MPI.ERR_COUNT: int = ERR_COUNT
Constant ERR_COUNT of type int
mpi4py.MPI.ERR_TAG
mpi4py.MPI.ERR_TAG: int = ERR_TAG
Constant ERR_TAG of type int
mpi4py.MPI.ERR_RANK
mpi4py.MPI.ERR_RANK: int = ERR_RANK
Constant ERR_RANK of type int
mpi4py.MPI.ERR_ROOT
mpi4py.MPI.ERR_ROOT: int = ERR_ROOT
Constant ERR_ROOT of type int
mpi4py.MPI.ERR_TRUNCATE
mpi4py.MPI.ERR_TRUNCATE: int = ERR_TRUNCATE
Constant ERR_TRUNCATE of type int
mpi4py.MPI.ERR_IN_STATUS
mpi4py.MPI.ERR_IN_STATUS: int = ERR_IN_STATUS
Constant ERR_IN_STATUS of type int
mpi4py.MPI.ERR_PENDING
mpi4py.MPI.ERR_PENDING: int = ERR_PENDING
Constant ERR_PENDING of type int
mpi4py.MPI.ERR_TOPOLOGY
mpi4py.MPI.ERR_TOPOLOGY: int = ERR_TOPOLOGY
Constant ERR_TOPOLOGY of type int
mpi4py.MPI.ERR_DIMS
mpi4py.MPI.ERR_DIMS: int = ERR_DIMS
Constant ERR_DIMS of type int
mpi4py.MPI.ERR_ARG
mpi4py.MPI.ERR_ARG: int = ERR_ARG
Constant ERR_ARG of type int
mpi4py.MPI.ERR_OTHER
mpi4py.MPI.ERR_OTHER: int = ERR_OTHER
Constant ERR_OTHER of type int
mpi4py.MPI.ERR_UNKNOWN
mpi4py.MPI.ERR_UNKNOWN: int = ERR_UNKNOWN
Constant ERR_UNKNOWN of type int
mpi4py.MPI.ERR_INTERN
mpi4py.MPI.ERR_INTERN: int = ERR_INTERN
Constant ERR_INTERN of type int
mpi4py.MPI.ERR_KEYVAL
mpi4py.MPI.ERR_KEYVAL: int = ERR_KEYVAL
Constant ERR_KEYVAL of type int
mpi4py.MPI.ERR_NO_MEM
mpi4py.MPI.ERR_NO_MEM: int = ERR_NO_MEM
Constant ERR_NO_MEM of type int
mpi4py.MPI.ERR_INFO_KEY
mpi4py.MPI.ERR_INFO_KEY: int = ERR_INFO_KEY
Constant ERR_INFO_KEY of type int
mpi4py.MPI.ERR_INFO_VALUE
mpi4py.MPI.ERR_INFO_VALUE: int = ERR_INFO_VALUE
Constant ERR_INFO_VALUE of type int
mpi4py.MPI.ERR_INFO_NOKEY
mpi4py.MPI.ERR_INFO_NOKEY: int = ERR_INFO_NOKEY
Constant ERR_INFO_NOKEY of type int
mpi4py.MPI.ERR_SPAWN
mpi4py.MPI.ERR_SPAWN: int = ERR_SPAWN
Constant ERR_SPAWN of type int
mpi4py.MPI.ERR_PORT
mpi4py.MPI.ERR_PORT: int = ERR_PORT
Constant ERR_PORT of type int
mpi4py.MPI.ERR_SERVICE
mpi4py.MPI.ERR_SERVICE: int = ERR_SERVICE
Constant ERR_SERVICE of type int
mpi4py.MPI.ERR_NAME
mpi4py.MPI.ERR_NAME: int = ERR_NAME
Constant ERR_NAME of type int
mpi4py.MPI.ERR_PROC_ABORTED
mpi4py.MPI.ERR_PROC_ABORTED: int = ERR_PROC_ABORTED
Constant ERR_PROC_ABORTED of type int
mpi4py.MPI.ERR_BASE
mpi4py.MPI.ERR_BASE: int = ERR_BASE
Constant ERR_BASE of type int
mpi4py.MPI.ERR_SIZE
mpi4py.MPI.ERR_SIZE: int = ERR_SIZE
Constant ERR_SIZE of type int
mpi4py.MPI.ERR_DISP
mpi4py.MPI.ERR_DISP: int = ERR_DISP
Constant ERR_DISP of type int
mpi4py.MPI.ERR_ASSERT
mpi4py.MPI.ERR_ASSERT: int = ERR_ASSERT
Constant ERR_ASSERT of type int
mpi4py.MPI.ERR_LOCKTYPE
mpi4py.MPI.ERR_LOCKTYPE: int = ERR_LOCKTYPE
Constant ERR_LOCKTYPE of type int
mpi4py.MPI.ERR_RMA_CONFLICT
mpi4py.MPI.ERR_RMA_CONFLICT: int = ERR_RMA_CONFLICT
Constant ERR_RMA_CONFLICT of type int
mpi4py.MPI.ERR_RMA_SYNC
mpi4py.MPI.ERR_RMA_SYNC: int = ERR_RMA_SYNC
Constant ERR_RMA_SYNC of type int
mpi4py.MPI.ERR_RMA_RANGE
mpi4py.MPI.ERR_RMA_RANGE: int = ERR_RMA_RANGE
Constant ERR_RMA_RANGE of type int
mpi4py.MPI.ERR_RMA_ATTACH
mpi4py.MPI.ERR_RMA_ATTACH: int = ERR_RMA_ATTACH
Constant ERR_RMA_ATTACH of type int
mpi4py.MPI.ERR_RMA_SHARED
mpi4py.MPI.ERR_RMA_SHARED: int = ERR_RMA_SHARED
Constant ERR_RMA_SHARED of type int
mpi4py.MPI.ERR_RMA_FLAVOR
mpi4py.MPI.ERR_RMA_FLAVOR: int = ERR_RMA_FLAVOR
Constant ERR_RMA_FLAVOR of type int
mpi4py.MPI.ERR_BAD_FILE
mpi4py.MPI.ERR_BAD_FILE: int = ERR_BAD_FILE
Constant ERR_BAD_FILE of type int
mpi4py.MPI.ERR_NO_SUCH_FILE
mpi4py.MPI.ERR_NO_SUCH_FILE: int = ERR_NO_SUCH_FILE
Constant ERR_NO_SUCH_FILE of type int
mpi4py.MPI.ERR_FILE_EXISTS
mpi4py.MPI.ERR_FILE_EXISTS: int = ERR_FILE_EXISTS
Constant ERR_FILE_EXISTS of type int
mpi4py.MPI.ERR_FILE_IN_USE
mpi4py.MPI.ERR_FILE_IN_USE: int = ERR_FILE_IN_USE
Constant ERR_FILE_IN_USE of type int
mpi4py.MPI.ERR_AMODE
mpi4py.MPI.ERR_AMODE: int = ERR_AMODE
Constant ERR_AMODE of type int
mpi4py.MPI.ERR_ACCESS
mpi4py.MPI.ERR_ACCESS: int = ERR_ACCESS
Constant ERR_ACCESS of type int
mpi4py.MPI.ERR_READ_ONLY
mpi4py.MPI.ERR_READ_ONLY: int = ERR_READ_ONLY
Constant ERR_READ_ONLY of type int
mpi4py.MPI.ERR_NO_SPACE
mpi4py.MPI.ERR_NO_SPACE: int = ERR_NO_SPACE
Constant ERR_NO_SPACE of type int
mpi4py.MPI.ERR_QUOTA
mpi4py.MPI.ERR_QUOTA: int = ERR_QUOTA
Constant ERR_QUOTA of type int
mpi4py.MPI.ERR_NOT_SAME
mpi4py.MPI.ERR_NOT_SAME: int = ERR_NOT_SAME
Constant ERR_NOT_SAME of type int
mpi4py.MPI.ERR_IO
mpi4py.MPI.ERR_IO: int = ERR_IO
Constant ERR_IO of type int
mpi4py.MPI.ERR_UNSUPPORTED_OPERATION
mpi4py.MPI.ERR_UNSUPPORTED_OPERATION: int = ERR_UNSUPPORTED_OPERATION
Constant ERR_UNSUPPORTED_OPERATION of type int
mpi4py.MPI.ERR_UNSUPPORTED_DATAREP
mpi4py.MPI.ERR_UNSUPPORTED_DATAREP: int = ERR_UNSUPPORTED_DATAREP
Constant ERR_UNSUPPORTED_DATAREP of type int
mpi4py.MPI.ERR_CONVERSION
mpi4py.MPI.ERR_CONVERSION: int = ERR_CONVERSION
Constant ERR_CONVERSION of type int
mpi4py.MPI.ERR_DUP_DATAREP
mpi4py.MPI.ERR_DUP_DATAREP: int = ERR_DUP_DATAREP
Constant ERR_DUP_DATAREP of type int
mpi4py.MPI.ERR_VALUE_TOO_LARGE
mpi4py.MPI.ERR_VALUE_TOO_LARGE: int = ERR_VALUE_TOO_LARGE
Constant ERR_VALUE_TOO_LARGE of type int
mpi4py.MPI.ERR_REVOKED
mpi4py.MPI.ERR_REVOKED: int = ERR_REVOKED
Constant ERR_REVOKED of type int
mpi4py.MPI.ERR_PROC_FAILED
mpi4py.MPI.ERR_PROC_FAILED: int = ERR_PROC_FAILED
Constant ERR_PROC_FAILED of type int
mpi4py.MPI.ERR_PROC_FAILED_PENDING
mpi4py.MPI.ERR_PROC_FAILED_PENDING: int = ERR_PROC_FAILED_PENDING
Constant ERR_PROC_FAILED_PENDING of type int
mpi4py.MPI.ORDER_C
mpi4py.MPI.ORDER_C: int = ORDER_C
Constant ORDER_C of type int
mpi4py.MPI.ORDER_FORTRAN
mpi4py.MPI.ORDER_FORTRAN: int = ORDER_FORTRAN
Constant ORDER_FORTRAN of type int
mpi4py.MPI.ORDER_F
mpi4py.MPI.ORDER_F: int = ORDER_F
Constant ORDER_F of type int
mpi4py.MPI.TYPECLASS_INTEGER
mpi4py.MPI.TYPECLASS_INTEGER: int = TYPECLASS_INTEGER
Constant TYPECLASS_INTEGER of type int
mpi4py.MPI.TYPECLASS_REAL
mpi4py.MPI.TYPECLASS_REAL: int = TYPECLASS_REAL
Constant TYPECLASS_REAL of type int
mpi4py.MPI.TYPECLASS_COMPLEX
mpi4py.MPI.TYPECLASS_COMPLEX: int = TYPECLASS_COMPLEX
Constant TYPECLASS_COMPLEX of type int
mpi4py.MPI.DISTRIBUTE_NONE
mpi4py.MPI.DISTRIBUTE_NONE: int = DISTRIBUTE_NONE
Constant DISTRIBUTE_NONE of type int
mpi4py.MPI.DISTRIBUTE_BLOCK
mpi4py.MPI.DISTRIBUTE_BLOCK: int = DISTRIBUTE_BLOCK
Constant DISTRIBUTE_BLOCK of type int
mpi4py.MPI.DISTRIBUTE_CYCLIC
mpi4py.MPI.DISTRIBUTE_CYCLIC: int = DISTRIBUTE_CYCLIC
Constant DISTRIBUTE_CYCLIC of type int
mpi4py.MPI.DISTRIBUTE_DFLT_DARG
mpi4py.MPI.DISTRIBUTE_DFLT_DARG: int = DISTRIBUTE_DFLT_DARG
Constant DISTRIBUTE_DFLT_DARG of type int
mpi4py.MPI.COMBINER_NAMED
mpi4py.MPI.COMBINER_NAMED: int = COMBINER_NAMED
Constant COMBINER_NAMED of type int
mpi4py.MPI.COMBINER_DUP
mpi4py.MPI.COMBINER_DUP: int = COMBINER_DUP
Constant COMBINER_DUP of type int
mpi4py.MPI.COMBINER_CONTIGUOUS
mpi4py.MPI.COMBINER_CONTIGUOUS: int = COMBINER_CONTIGUOUS
Constant COMBINER_CONTIGUOUS of type int
mpi4py.MPI.COMBINER_VECTOR
mpi4py.MPI.COMBINER_VECTOR: int = COMBINER_VECTOR
Constant COMBINER_VECTOR of type int
mpi4py.MPI.COMBINER_HVECTOR
mpi4py.MPI.COMBINER_HVECTOR: int = COMBINER_HVECTOR
Constant COMBINER_HVECTOR of type int
mpi4py.MPI.COMBINER_INDEXED
mpi4py.MPI.COMBINER_INDEXED: int = COMBINER_INDEXED
Constant COMBINER_INDEXED of type int
mpi4py.MPI.COMBINER_HINDEXED
mpi4py.MPI.COMBINER_HINDEXED: int = COMBINER_HINDEXED
Constant COMBINER_HINDEXED of type int
mpi4py.MPI.COMBINER_INDEXED_BLOCK
mpi4py.MPI.COMBINER_INDEXED_BLOCK: int = COMBINER_INDEXED_BLOCK
Constant COMBINER_INDEXED_BLOCK of type int
mpi4py.MPI.COMBINER_HINDEXED_BLOCK
mpi4py.MPI.COMBINER_HINDEXED_BLOCK: int = COMBINER_HINDEXED_BLOCK
Constant COMBINER_HINDEXED_BLOCK of type int
mpi4py.MPI.COMBINER_STRUCT
mpi4py.MPI.COMBINER_STRUCT: int = COMBINER_STRUCT
Constant COMBINER_STRUCT of type int
mpi4py.MPI.COMBINER_SUBARRAY
mpi4py.MPI.COMBINER_SUBARRAY: int = COMBINER_SUBARRAY
Constant COMBINER_SUBARRAY of type int
mpi4py.MPI.COMBINER_DARRAY
mpi4py.MPI.COMBINER_DARRAY: int = COMBINER_DARRAY
Constant COMBINER_DARRAY of type int
mpi4py.MPI.COMBINER_RESIZED
mpi4py.MPI.COMBINER_RESIZED: int = COMBINER_RESIZED
Constant COMBINER_RESIZED of type int
mpi4py.MPI.COMBINER_VALUE_INDEX
mpi4py.MPI.COMBINER_VALUE_INDEX: int = COMBINER_VALUE_INDEX
Constant COMBINER_VALUE_INDEX of type int
mpi4py.MPI.COMBINER_F90_INTEGER
mpi4py.MPI.COMBINER_F90_INTEGER: int = COMBINER_F90_INTEGER
Constant COMBINER_F90_INTEGER of type int
mpi4py.MPI.COMBINER_F90_REAL
mpi4py.MPI.COMBINER_F90_REAL: int = COMBINER_F90_REAL
Constant COMBINER_F90_REAL of type int
mpi4py.MPI.COMBINER_F90_COMPLEX
mpi4py.MPI.COMBINER_F90_COMPLEX: int = COMBINER_F90_COMPLEX
Constant COMBINER_F90_COMPLEX of type int
mpi4py.MPI.F_SOURCE
mpi4py.MPI.F_SOURCE: int = F_SOURCE
Constant F_SOURCE of type int
mpi4py.MPI.F_TAG
mpi4py.MPI.F_TAG: int = F_TAG
Constant F_TAG of type int
mpi4py.MPI.F_ERROR
mpi4py.MPI.F_ERROR: int = F_ERROR
Constant F_ERROR of type int
mpi4py.MPI.F_STATUS_SIZE
mpi4py.MPI.F_STATUS_SIZE: int = F_STATUS_SIZE
Constant F_STATUS_SIZE of type int
mpi4py.MPI.IDENT
mpi4py.MPI.IDENT: int = IDENT
Constant IDENT of type int
mpi4py.MPI.CONGRUENT
mpi4py.MPI.CONGRUENT: int = CONGRUENT
Constant CONGRUENT of type int
mpi4py.MPI.SIMILAR
mpi4py.MPI.SIMILAR: int = SIMILAR
Constant SIMILAR of type int
mpi4py.MPI.UNEQUAL
mpi4py.MPI.UNEQUAL: int = UNEQUAL
Constant UNEQUAL of type int
mpi4py.MPI.CART
mpi4py.MPI.CART: int = CART
Constant CART of type int
mpi4py.MPI.GRAPH
mpi4py.MPI.GRAPH: int = GRAPH
Constant GRAPH of type int
mpi4py.MPI.DIST_GRAPH
mpi4py.MPI.DIST_GRAPH: int = DIST_GRAPH
Constant DIST_GRAPH of type int
mpi4py.MPI.UNWEIGHTED
mpi4py.MPI.UNWEIGHTED: int = UNWEIGHTED
Constant UNWEIGHTED of type int
mpi4py.MPI.WEIGHTS_EMPTY
mpi4py.MPI.WEIGHTS_EMPTY: int = WEIGHTS_EMPTY
Constant WEIGHTS_EMPTY of type int
mpi4py.MPI.COMM_TYPE_SHARED
mpi4py.MPI.COMM_TYPE_SHARED: int = COMM_TYPE_SHARED
Constant COMM_TYPE_SHARED of type int
mpi4py.MPI.COMM_TYPE_HW_GUIDED
mpi4py.MPI.COMM_TYPE_HW_GUIDED: int = COMM_TYPE_HW_GUIDED
Constant COMM_TYPE_HW_GUIDED of type int
mpi4py.MPI.COMM_TYPE_HW_UNGUIDED
mpi4py.MPI.COMM_TYPE_HW_UNGUIDED: int = COMM_TYPE_HW_UNGUIDED
Constant COMM_TYPE_HW_UNGUIDED of type int
mpi4py.MPI.COMM_TYPE_RESOURCE_GUIDED
mpi4py.MPI.COMM_TYPE_RESOURCE_GUIDED: int = COMM_TYPE_RESOURCE_GUIDED
Constant COMM_TYPE_RESOURCE_GUIDED of type int
mpi4py.MPI.BSEND_OVERHEAD
mpi4py.MPI.BSEND_OVERHEAD: int = BSEND_OVERHEAD
Constant BSEND_OVERHEAD of type int
mpi4py.MPI.BUFFER_AUTOMATIC
mpi4py.MPI.BUFFER_AUTOMATIC: BufferAutomaticType = BUFFER_AUTOMATIC
Constant BUFFER_AUTOMATIC of type BufferAutomaticType
mpi4py.MPI.WIN_FLAVOR_CREATE
mpi4py.MPI.WIN_FLAVOR_CREATE: int = WIN_FLAVOR_CREATE
Constant WIN_FLAVOR_CREATE of type int
mpi4py.MPI.WIN_FLAVOR_ALLOCATE
mpi4py.MPI.WIN_FLAVOR_ALLOCATE: int = WIN_FLAVOR_ALLOCATE
Constant WIN_FLAVOR_ALLOCATE of type int
mpi4py.MPI.WIN_FLAVOR_DYNAMIC
mpi4py.MPI.WIN_FLAVOR_DYNAMIC: int = WIN_FLAVOR_DYNAMIC
Constant WIN_FLAVOR_DYNAMIC of type int
mpi4py.MPI.WIN_FLAVOR_SHARED
mpi4py.MPI.WIN_FLAVOR_SHARED: int = WIN_FLAVOR_SHARED
Constant WIN_FLAVOR_SHARED of type int
mpi4py.MPI.WIN_SEPARATE
mpi4py.MPI.WIN_SEPARATE: int = WIN_SEPARATE
Constant WIN_SEPARATE of type int
mpi4py.MPI.WIN_UNIFIED
mpi4py.MPI.WIN_UNIFIED: int = WIN_UNIFIED
Constant WIN_UNIFIED of type int
mpi4py.MPI.MODE_NOCHECK
mpi4py.MPI.MODE_NOCHECK: int = MODE_NOCHECK
Constant MODE_NOCHECK of type int
mpi4py.MPI.MODE_NOSTORE
mpi4py.MPI.MODE_NOSTORE: int = MODE_NOSTORE
Constant MODE_NOSTORE of type int
mpi4py.MPI.MODE_NOPUT
mpi4py.MPI.MODE_NOPUT: int = MODE_NOPUT
Constant MODE_NOPUT of type int
mpi4py.MPI.MODE_NOPRECEDE
mpi4py.MPI.MODE_NOPRECEDE: int = MODE_NOPRECEDE
Constant MODE_NOPRECEDE of type int
mpi4py.MPI.MODE_NOSUCCEED
mpi4py.MPI.MODE_NOSUCCEED: int = MODE_NOSUCCEED
Constant MODE_NOSUCCEED of type int
mpi4py.MPI.LOCK_EXCLUSIVE
mpi4py.MPI.LOCK_EXCLUSIVE: int = LOCK_EXCLUSIVE
Constant LOCK_EXCLUSIVE of type int
mpi4py.MPI.LOCK_SHARED
mpi4py.MPI.LOCK_SHARED: int = LOCK_SHARED
Constant LOCK_SHARED of type int
mpi4py.MPI.MODE_RDONLY
mpi4py.MPI.MODE_RDONLY: int = MODE_RDONLY
Constant MODE_RDONLY of type int
mpi4py.MPI.MODE_WRONLY
mpi4py.MPI.MODE_WRONLY: int = MODE_WRONLY
Constant MODE_WRONLY of type int
mpi4py.MPI.MODE_RDWR
mpi4py.MPI.MODE_RDWR: int = MODE_RDWR
Constant MODE_RDWR of type int
mpi4py.MPI.MODE_CREATE
mpi4py.MPI.MODE_CREATE: int = MODE_CREATE
Constant MODE_CREATE of type int
mpi4py.MPI.MODE_EXCL
mpi4py.MPI.MODE_EXCL: int = MODE_EXCL
Constant MODE_EXCL of type int
mpi4py.MPI.MODE_DELETE_ON_CLOSE
mpi4py.MPI.MODE_DELETE_ON_CLOSE: int = MODE_DELETE_ON_CLOSE
Constant MODE_DELETE_ON_CLOSE of type int
mpi4py.MPI.MODE_UNIQUE_OPEN
mpi4py.MPI.MODE_UNIQUE_OPEN: int = MODE_UNIQUE_OPEN
Constant MODE_UNIQUE_OPEN of type int
mpi4py.MPI.MODE_SEQUENTIAL
mpi4py.MPI.MODE_SEQUENTIAL: int = MODE_SEQUENTIAL
Constant MODE_SEQUENTIAL of type int
mpi4py.MPI.MODE_APPEND
mpi4py.MPI.MODE_APPEND: int = MODE_APPEND
Constant MODE_APPEND of type int
mpi4py.MPI.SEEK_SET
mpi4py.MPI.SEEK_SET: int = SEEK_SET
Constant SEEK_SET of type int
mpi4py.MPI.SEEK_CUR
mpi4py.MPI.SEEK_CUR: int = SEEK_CUR
Constant SEEK_CUR of type int
mpi4py.MPI.SEEK_END
mpi4py.MPI.SEEK_END: int = SEEK_END
Constant SEEK_END of type int
mpi4py.MPI.DISPLACEMENT_CURRENT
mpi4py.MPI.DISPLACEMENT_CURRENT: int = DISPLACEMENT_CURRENT
Constant DISPLACEMENT_CURRENT of type int
mpi4py.MPI.DISP_CUR
mpi4py.MPI.DISP_CUR: int = DISP_CUR
Constant DISP_CUR of type int
mpi4py.MPI.THREAD_SINGLE
mpi4py.MPI.THREAD_SINGLE: int = THREAD_SINGLE
Constant THREAD_SINGLE of type int
mpi4py.MPI.THREAD_FUNNELED
mpi4py.MPI.THREAD_FUNNELED: int = THREAD_FUNNELED
Constant THREAD_FUNNELED of type int
mpi4py.MPI.THREAD_SERIALIZED
mpi4py.MPI.THREAD_SERIALIZED: int = THREAD_SERIALIZED
Constant THREAD_SERIALIZED of type int
mpi4py.MPI.THREAD_MULTIPLE
mpi4py.MPI.THREAD_MULTIPLE: int = THREAD_MULTIPLE
Constant THREAD_MULTIPLE of type int
mpi4py.MPI.VERSION
mpi4py.MPI.VERSION: int = VERSION
Constant VERSION of type int
mpi4py.MPI.SUBVERSION
mpi4py.MPI.SUBVERSION: int = SUBVERSION
Constant SUBVERSION of type int
mpi4py.MPI.MAX_PROCESSOR_NAME
mpi4py.MPI.MAX_PROCESSOR_NAME: int = MAX_PROCESSOR_NAME
Constant MAX_PROCESSOR_NAME of type int
mpi4py.MPI.MAX_ERROR_STRING
mpi4py.MPI.MAX_ERROR_STRING: int = MAX_ERROR_STRING
Constant MAX_ERROR_STRING of type int
mpi4py.MPI.MAX_PORT_NAME
mpi4py.MPI.MAX_PORT_NAME: int = MAX_PORT_NAME
Constant MAX_PORT_NAME of type int
mpi4py.MPI.MAX_INFO_KEY
mpi4py.MPI.MAX_INFO_KEY: int = MAX_INFO_KEY
Constant MAX_INFO_KEY of type int
mpi4py.MPI.MAX_INFO_VAL
mpi4py.MPI.MAX_INFO_VAL: int = MAX_INFO_VAL
Constant MAX_INFO_VAL of type int
mpi4py.MPI.MAX_OBJECT_NAME
mpi4py.MPI.MAX_OBJECT_NAME: int = MAX_OBJECT_NAME
Constant MAX_OBJECT_NAME of type int
mpi4py.MPI.MAX_DATAREP_STRING
mpi4py.MPI.MAX_DATAREP_STRING: int = MAX_DATAREP_STRING
Constant MAX_DATAREP_STRING of type int
mpi4py.MPI.MAX_LIBRARY_VERSION_STRING
mpi4py.MPI.MAX_LIBRARY_VERSION_STRING: int = MAX_LIBRARY_VERSION_STRING
Constant MAX_LIBRARY_VERSION_STRING of type int
mpi4py.MPI.MAX_PSET_NAME_LEN
mpi4py.MPI.MAX_PSET_NAME_LEN: int = MAX_PSET_NAME_LEN
Constant MAX_PSET_NAME_LEN of type int
mpi4py.MPI.MAX_STRINGTAG_LEN
mpi4py.MPI.MAX_STRINGTAG_LEN: int = MAX_STRINGTAG_LEN
Constant MAX_STRINGTAG_LEN of type int
mpi4py.MPI.DATATYPE_NULL
mpi4py.MPI.DATATYPE_NULL: Datatype = DATATYPE_NULL
Object DATATYPE_NULL of type Datatype
mpi4py.MPI.PACKED
mpi4py.MPI.PACKED: Datatype = PACKED
Object PACKED of type Datatype
mpi4py.MPI.BYTE
mpi4py.MPI.BYTE: Datatype = BYTE
Object BYTE of type Datatype
mpi4py.MPI.AINT
mpi4py.MPI.AINT: Datatype = AINT
Object AINT of type Datatype
mpi4py.MPI.OFFSET
mpi4py.MPI.OFFSET: Datatype = OFFSET
Object OFFSET of type Datatype
mpi4py.MPI.COUNT
mpi4py.MPI.COUNT: Datatype = COUNT
Object COUNT of type Datatype
mpi4py.MPI.CHAR
mpi4py.MPI.CHAR: Datatype = CHAR
Object CHAR of type Datatype
mpi4py.MPI.WCHAR
mpi4py.MPI.WCHAR: Datatype = WCHAR
Object WCHAR of type Datatype
mpi4py.MPI.SIGNED_CHAR
mpi4py.MPI.SIGNED_CHAR: Datatype = SIGNED_CHAR
Object SIGNED_CHAR of type Datatype
mpi4py.MPI.SHORT
mpi4py.MPI.SHORT: Datatype = SHORT
Object SHORT of type Datatype
mpi4py.MPI.INT
mpi4py.MPI.INT: Datatype = INT
Object INT of type Datatype
mpi4py.MPI.LONG
mpi4py.MPI.LONG: Datatype = LONG
Object LONG of type Datatype
mpi4py.MPI.LONG_LONG
mpi4py.MPI.LONG_LONG: Datatype = LONG_LONG
Object LONG_LONG of type Datatype
mpi4py.MPI.UNSIGNED_CHAR
mpi4py.MPI.UNSIGNED_CHAR: Datatype = UNSIGNED_CHAR
Object UNSIGNED_CHAR of type Datatype
mpi4py.MPI.UNSIGNED_SHORT
mpi4py.MPI.UNSIGNED_SHORT: Datatype = UNSIGNED_SHORT
Object UNSIGNED_SHORT of type Datatype
mpi4py.MPI.UNSIGNED
mpi4py.MPI.UNSIGNED: Datatype = UNSIGNED
Object UNSIGNED of type Datatype
mpi4py.MPI.UNSIGNED_LONG
mpi4py.MPI.UNSIGNED_LONG: Datatype = UNSIGNED_LONG
Object UNSIGNED_LONG of type Datatype
mpi4py.MPI.UNSIGNED_LONG_LONG
mpi4py.MPI.UNSIGNED_LONG_LONG: Datatype = UNSIGNED_LONG_LONG
Object UNSIGNED_LONG_LONG of type Datatype
mpi4py.MPI.FLOAT
mpi4py.MPI.FLOAT: Datatype = FLOAT
Object FLOAT of type Datatype
mpi4py.MPI.DOUBLE
mpi4py.MPI.DOUBLE: Datatype = DOUBLE
Object DOUBLE of type Datatype
mpi4py.MPI.LONG_DOUBLE
mpi4py.MPI.LONG_DOUBLE: Datatype = LONG_DOUBLE
Object LONG_DOUBLE of type Datatype
mpi4py.MPI.C_BOOL
mpi4py.MPI.C_BOOL: Datatype = C_BOOL
Object C_BOOL of type Datatype
mpi4py.MPI.INT8_T
mpi4py.MPI.INT8_T: Datatype = INT8_T
Object INT8_T of type Datatype
mpi4py.MPI.INT16_T
mpi4py.MPI.INT16_T: Datatype = INT16_T
Object INT16_T of type Datatype
mpi4py.MPI.INT32_T
mpi4py.MPI.INT32_T: Datatype = INT32_T
Object INT32_T of type Datatype
mpi4py.MPI.INT64_T
mpi4py.MPI.INT64_T: Datatype = INT64_T
Object INT64_T of type Datatype
mpi4py.MPI.UINT8_T
mpi4py.MPI.UINT8_T: Datatype = UINT8_T
Object UINT8_T of type Datatype
mpi4py.MPI.UINT16_T
mpi4py.MPI.UINT16_T: Datatype = UINT16_T
Object UINT16_T of type Datatype
mpi4py.MPI.UINT32_T
mpi4py.MPI.UINT32_T: Datatype = UINT32_T
Object UINT32_T of type Datatype
mpi4py.MPI.UINT64_T
mpi4py.MPI.UINT64_T: Datatype = UINT64_T
Object UINT64_T of type Datatype
mpi4py.MPI.C_COMPLEX
mpi4py.MPI.C_COMPLEX: Datatype = C_COMPLEX
Object C_COMPLEX of type Datatype
mpi4py.MPI.C_FLOAT_COMPLEX
mpi4py.MPI.C_FLOAT_COMPLEX: Datatype = C_FLOAT_COMPLEX
Object C_FLOAT_COMPLEX of type Datatype
mpi4py.MPI.C_DOUBLE_COMPLEX
mpi4py.MPI.C_DOUBLE_COMPLEX: Datatype = C_DOUBLE_COMPLEX
Object C_DOUBLE_COMPLEX of type Datatype
mpi4py.MPI.C_LONG_DOUBLE_COMPLEX
mpi4py.MPI.C_LONG_DOUBLE_COMPLEX: Datatype = C_LONG_DOUBLE_COMPLEX
Object C_LONG_DOUBLE_COMPLEX of type Datatype
mpi4py.MPI.CXX_BOOL
mpi4py.MPI.CXX_BOOL: Datatype = CXX_BOOL
Object CXX_BOOL of type Datatype
mpi4py.MPI.CXX_FLOAT_COMPLEX
mpi4py.MPI.CXX_FLOAT_COMPLEX: Datatype = CXX_FLOAT_COMPLEX
Object CXX_FLOAT_COMPLEX of type Datatype
mpi4py.MPI.CXX_DOUBLE_COMPLEX
mpi4py.MPI.CXX_DOUBLE_COMPLEX: Datatype = CXX_DOUBLE_COMPLEX
Object CXX_DOUBLE_COMPLEX of type Datatype
mpi4py.MPI.CXX_LONG_DOUBLE_COMPLEX
mpi4py.MPI.CXX_LONG_DOUBLE_COMPLEX: Datatype = CXX_LONG_DOUBLE_COMPLEX
Object CXX_LONG_DOUBLE_COMPLEX of type Datatype
mpi4py.MPI.SHORT_INT
mpi4py.MPI.SHORT_INT: Datatype = SHORT_INT
Object SHORT_INT of type Datatype
mpi4py.MPI.INT_INT
mpi4py.MPI.INT_INT: Datatype = INT_INT
Object INT_INT of type Datatype
mpi4py.MPI.TWOINT
mpi4py.MPI.TWOINT: Datatype = TWOINT
Object TWOINT of type Datatype
mpi4py.MPI.LONG_INT
mpi4py.MPI.LONG_INT: Datatype = LONG_INT
Object LONG_INT of type Datatype
mpi4py.MPI.FLOAT_INT
mpi4py.MPI.FLOAT_INT: Datatype = FLOAT_INT
Object FLOAT_INT of type Datatype
mpi4py.MPI.DOUBLE_INT
mpi4py.MPI.DOUBLE_INT: Datatype = DOUBLE_INT
Object DOUBLE_INT of type Datatype
mpi4py.MPI.LONG_DOUBLE_INT
mpi4py.MPI.LONG_DOUBLE_INT: Datatype = LONG_DOUBLE_INT
Object LONG_DOUBLE_INT of type Datatype
mpi4py.MPI.CHARACTER
mpi4py.MPI.CHARACTER: Datatype = CHARACTER
Object CHARACTER of type Datatype
mpi4py.MPI.LOGICAL
mpi4py.MPI.LOGICAL: Datatype = LOGICAL
Object LOGICAL of type Datatype
mpi4py.MPI.INTEGER
mpi4py.MPI.INTEGER: Datatype = INTEGER
Object INTEGER of type Datatype
mpi4py.MPI.REAL
mpi4py.MPI.REAL: Datatype = REAL
Object REAL of type Datatype
mpi4py.MPI.DOUBLE_PRECISION
mpi4py.MPI.DOUBLE_PRECISION: Datatype = DOUBLE_PRECISION
Object DOUBLE_PRECISION of type Datatype
mpi4py.MPI.COMPLEX
mpi4py.MPI.COMPLEX: Datatype = COMPLEX
Object COMPLEX of type Datatype
mpi4py.MPI.DOUBLE_COMPLEX
mpi4py.MPI.DOUBLE_COMPLEX: Datatype = DOUBLE_COMPLEX
Object DOUBLE_COMPLEX of type Datatype
mpi4py.MPI.LOGICAL1
mpi4py.MPI.LOGICAL1: Datatype = LOGICAL1
Object LOGICAL1 of type Datatype
mpi4py.MPI.LOGICAL2
mpi4py.MPI.LOGICAL2: Datatype = LOGICAL2
Object LOGICAL2 of type Datatype
mpi4py.MPI.LOGICAL4
mpi4py.MPI.LOGICAL4: Datatype = LOGICAL4
Object LOGICAL4 of type Datatype
mpi4py.MPI.LOGICAL8
mpi4py.MPI.LOGICAL8: Datatype = LOGICAL8
Object LOGICAL8 of type Datatype
mpi4py.MPI.INTEGER1
mpi4py.MPI.INTEGER1: Datatype = INTEGER1
Object INTEGER1 of type Datatype
mpi4py.MPI.INTEGER2
mpi4py.MPI.INTEGER2: Datatype = INTEGER2
Object INTEGER2 of type Datatype
mpi4py.MPI.INTEGER4
mpi4py.MPI.INTEGER4: Datatype = INTEGER4
Object INTEGER4 of type Datatype
mpi4py.MPI.INTEGER8
mpi4py.MPI.INTEGER8: Datatype = INTEGER8
Object INTEGER8 of type Datatype
mpi4py.MPI.INTEGER16
mpi4py.MPI.INTEGER16: Datatype = INTEGER16
Object INTEGER16 of type Datatype
mpi4py.MPI.REAL2
mpi4py.MPI.REAL2: Datatype = REAL2
Object REAL2 of type Datatype
mpi4py.MPI.REAL4
mpi4py.MPI.REAL4: Datatype = REAL4
Object REAL4 of type Datatype
mpi4py.MPI.REAL8
mpi4py.MPI.REAL8: Datatype = REAL8
Object REAL8 of type Datatype
mpi4py.MPI.REAL16
mpi4py.MPI.REAL16: Datatype = REAL16
Object REAL16 of type Datatype
mpi4py.MPI.COMPLEX4
mpi4py.MPI.COMPLEX4: Datatype = COMPLEX4
Object COMPLEX4 of type Datatype
mpi4py.MPI.COMPLEX8
mpi4py.MPI.COMPLEX8: Datatype = COMPLEX8
Object COMPLEX8 of type Datatype
mpi4py.MPI.COMPLEX16
mpi4py.MPI.COMPLEX16: Datatype = COMPLEX16
Object COMPLEX16 of type Datatype
mpi4py.MPI.COMPLEX32
mpi4py.MPI.COMPLEX32: Datatype = COMPLEX32
Object COMPLEX32 of type Datatype
mpi4py.MPI.UNSIGNED_INT
mpi4py.MPI.UNSIGNED_INT: Datatype = UNSIGNED_INT
Object UNSIGNED_INT of type Datatype
mpi4py.MPI.SIGNED_SHORT
mpi4py.MPI.SIGNED_SHORT: Datatype = SIGNED_SHORT
Object SIGNED_SHORT of type Datatype
mpi4py.MPI.SIGNED_INT
mpi4py.MPI.SIGNED_INT: Datatype = SIGNED_INT
Object SIGNED_INT of type Datatype
mpi4py.MPI.SIGNED_LONG
mpi4py.MPI.SIGNED_LONG: Datatype = SIGNED_LONG
Object SIGNED_LONG of type Datatype
mpi4py.MPI.SIGNED_LONG_LONG
mpi4py.MPI.SIGNED_LONG_LONG: Datatype = SIGNED_LONG_LONG
Object SIGNED_LONG_LONG of type Datatype
mpi4py.MPI.BOOL
mpi4py.MPI.BOOL: Datatype = BOOL
Object BOOL of type Datatype
mpi4py.MPI.SINT8_T
mpi4py.MPI.SINT8_T: Datatype = SINT8_T
Object SINT8_T of type Datatype
mpi4py.MPI.SINT16_T
mpi4py.MPI.SINT16_T: Datatype = SINT16_T
Object SINT16_T of type Datatype
mpi4py.MPI.SINT32_T
mpi4py.MPI.SINT32_T: Datatype = SINT32_T
Object SINT32_T of type Datatype
mpi4py.MPI.SINT64_T
mpi4py.MPI.SINT64_T: Datatype = SINT64_T
Object SINT64_T of type Datatype
mpi4py.MPI.F_BOOL
mpi4py.MPI.F_BOOL: Datatype = F_BOOL
Object F_BOOL of type Datatype
mpi4py.MPI.F_INT
mpi4py.MPI.F_INT: Datatype = F_INT
Object F_INT of type Datatype
mpi4py.MPI.F_FLOAT
mpi4py.MPI.F_FLOAT: Datatype = F_FLOAT
Object F_FLOAT of type Datatype
mpi4py.MPI.F_DOUBLE
mpi4py.MPI.F_DOUBLE: Datatype = F_DOUBLE
Object F_DOUBLE of type Datatype
mpi4py.MPI.F_COMPLEX
mpi4py.MPI.F_COMPLEX: Datatype = F_COMPLEX
Object F_COMPLEX of type Datatype
mpi4py.MPI.F_FLOAT_COMPLEX
mpi4py.MPI.F_FLOAT_COMPLEX: Datatype = F_FLOAT_COMPLEX
Object F_FLOAT_COMPLEX of type Datatype
mpi4py.MPI.F_DOUBLE_COMPLEX
mpi4py.MPI.F_DOUBLE_COMPLEX: Datatype = F_DOUBLE_COMPLEX
Object F_DOUBLE_COMPLEX of type Datatype
mpi4py.MPI.REQUEST_NULL
mpi4py.MPI.REQUEST_NULL: Request = REQUEST_NULL
Object REQUEST_NULL of type Request
mpi4py.MPI.MESSAGE_NULL
mpi4py.MPI.MESSAGE_NULL: Message = MESSAGE_NULL
Object MESSAGE_NULL of type Message
mpi4py.MPI.MESSAGE_NO_PROC
mpi4py.MPI.MESSAGE_NO_PROC: Message = MESSAGE_NO_PROC
Object MESSAGE_NO_PROC of type Message
mpi4py.MPI.OP_NULL
mpi4py.MPI.OP_NULL: Op = OP_NULL
Object OP_NULL of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.MAX
mpi4py.MPI.MAX: Op = MAX
Object MAX of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.MIN
mpi4py.MPI.MIN: Op = MIN
Object MIN of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.SUM
mpi4py.MPI.SUM: Op = SUM
Object SUM of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.PROD
mpi4py.MPI.PROD: Op = PROD
Object PROD of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.LAND
mpi4py.MPI.LAND: Op = LAND
Object LAND of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.BAND
mpi4py.MPI.BAND: Op = BAND
Object BAND of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.LOR
mpi4py.MPI.LOR: Op = LOR
Object LOR of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.BOR
mpi4py.MPI.BOR: Op = BOR
Object BOR of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.LXOR
mpi4py.MPI.LXOR: Op = LXOR
Object LXOR of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.BXOR
mpi4py.MPI.BXOR: Op = BXOR
Object BXOR of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.MAXLOC
mpi4py.MPI.MAXLOC: Op = MAXLOC
Object MAXLOC of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.MINLOC
mpi4py.MPI.MINLOC: Op = MINLOC
Object MINLOC of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.REPLACE
mpi4py.MPI.REPLACE: Op = REPLACE
Object REPLACE of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.NO_OP
mpi4py.MPI.NO_OP: Op = NO_OP
Object NO_OP of type Op
Parameters
• x (Any)
• y (Any)
Return type
Any
mpi4py.MPI.GROUP_NULL
mpi4py.MPI.GROUP_NULL: Group = GROUP_NULL
Object GROUP_NULL of type Group
mpi4py.MPI.GROUP_EMPTY
mpi4py.MPI.GROUP_EMPTY: Group = GROUP_EMPTY
Object GROUP_EMPTY of type Group
mpi4py.MPI.INFO_NULL
mpi4py.MPI.INFO_NULL: Info = INFO_NULL
Object INFO_NULL of type Info
mpi4py.MPI.INFO_ENV
mpi4py.MPI.INFO_ENV: Info = INFO_ENV
Object INFO_ENV of type Info
mpi4py.MPI.ERRHANDLER_NULL
mpi4py.MPI.ERRHANDLER_NULL: Errhandler = ERRHANDLER_NULL
Object ERRHANDLER_NULL of type Errhandler
mpi4py.MPI.ERRORS_RETURN
mpi4py.MPI.ERRORS_RETURN: Errhandler = ERRORS_RETURN
Object ERRORS_RETURN of type Errhandler
mpi4py.MPI.ERRORS_ABORT
mpi4py.MPI.ERRORS_ABORT: Errhandler = ERRORS_ABORT
Object ERRORS_ABORT of type Errhandler
mpi4py.MPI.ERRORS_ARE_FATAL
mpi4py.MPI.ERRORS_ARE_FATAL: Errhandler = ERRORS_ARE_FATAL
Object ERRORS_ARE_FATAL of type Errhandler
mpi4py.MPI.SESSION_NULL
mpi4py.MPI.SESSION_NULL: Session = SESSION_NULL
Object SESSION_NULL of type Session
mpi4py.MPI.COMM_NULL
mpi4py.MPI.COMM_NULL: Comm = COMM_NULL
Object COMM_NULL of type Comm
mpi4py.MPI.COMM_SELF
mpi4py.MPI.COMM_SELF: Intracomm = COMM_SELF
Object COMM_SELF of type Intracomm
mpi4py.MPI.COMM_WORLD
mpi4py.MPI.COMM_WORLD: Intracomm = COMM_WORLD
Object COMM_WORLD of type Intracomm
mpi4py.MPI.WIN_NULL
mpi4py.MPI.WIN_NULL: Win = WIN_NULL
Object WIN_NULL of type Win
mpi4py.MPI.FILE_NULL
mpi4py.MPI.FILE_NULL: File = FILE_NULL
Object FILE_NULL of type File
mpi4py.MPI.pickle
mpi4py.MPI.pickle: Pickle = <mpi4py.MPI.Pickle object>
Object pickle of type Pickle
CITATION
If MPI for Python been significant to a project that leads to an academic publication, please acknowledge
that fact by citing the project.
• M. Rogowski, S. Aseeri, D. Keyes, and L. Dalcin, mpi4py.futures: MPI-Based Asynchronous Task Execution
for Python, IEEE Transactions on Parallel and Distributed Systems, 34(2):611-622, 2023. ‐
https://doi.org/10.1109/TPDS.2022.3225481
• L. Dalcin and Y.-L. L. Fang, mpi4py: Status Update After 12 Years of Development, Computing in Science
& Engineering, 23(4):47-54, 2021. https://doi.org/10.1109/MCSE.2021.3083216
• L. Dalcin, P. Kler, R. Paz, and A. Cosimo, Parallel Distributed Computing using Python, Advances in
Water Resources, 34(9):1124-1139, 2011. https://doi.org/10.1016/j.advwatres.2011.04.013
• L. Dalcin, R. Paz, M. Storti, and J. D’Elia, MPI for Python: performance improvements and MPI-2
extensions, Journal of Parallel and Distributed Computing, 68(5):655-662, 2008. ‐
https://doi.org/10.1016/j.jpdc.2007.09.005
• L. Dalcin, R. Paz, and M. Storti, MPI for Python, Journal of Parallel and Distributed Computing,
65(9):1108-1115, 2005. https://doi.org/10.1016/j.jpdc.2005.03.010
INSTALLATION
Build backends
mpi4py supports three different build backends: setuptools (default), scikit-build-core (CMake-based),
and meson-python (Meson-based). The build backend can be selected by setting the MPI4PY_BUILD_BACKEND
environment variable.
MPI4PY_BUILD_BACKEND
Choices
"setuptools", "scikit-build-core", "meson-python"
Default
"setuptools"
Request a build backend for building mpi4py from sources.
Using setuptools
TIP:
Set the MPI4PY_BUILD_BACKEND environment variable to "setuptools" to use the setuptools build backend.
When using the default setuptools build backend, mpi4py relies on the legacy Python distutils framework
to build C extension modules. The following environment variables affect the build configuration.
MPI4PY_BUILD_MPICC
The mpicc compiler wrapper command is searched for in the executable search path (PATH environment
variable) and used to compile the mpi4py.MPI C extension module. Alternatively, use the
MPI4PY_BUILD_MPICC environment variable to the full path or command corresponding to the MPI-aware
C compiler.
MPI4PY_BUILD_MPILD
The mpicc compiler wrapper command is also used for linking the mpi4py.MPI C extension module.
Alternatively, use the MPI4PY_BUILD_MPILD environment variable to specify the full path or command
corresponding to the MPI-aware C linker.
MPI4PY_BUILD_MPICFG
If the MPI implementation does not provide a compiler wrapper, or it is not installed in a default
system location, all relevant build information like include/library locations and library lists
can be provided in an ini-style configuration file under a [mpi] section. mpi4py can then be asked
to use the custom build information by setting the MPI4PY_BUILD_MPICFG environment variable to the
full path of the configuration file. As an example, see the mpi.cfg file located in the top level
mpi4py source directory.
MPI4PY_BUILD_CONFIGURE
Some vendor MPI implementations may not provide complete coverage of the MPI standard, or may
provide partial features of newer MPI standard versions while advertising support for an older
version. Setting the MPI4PY_BUILD_CONFIGURE environment variable to a non-empty string will
trigger the run of exhaustive checks for the availability of all MPI constants, predefined
handles, and routines.
The following environment variables are aliases for the ones described above. Having shorter names, they
are convenient for occasional use in the command line. Its usage is not recommended in automation
scenarios like packaging recipes, deployment scripts, and container image creation.
MPICC Convenience alias for MPI4PY_BUILD_MPICC.
MPILD Convenience alias for MPI4PY_BUILD_MPILD.
MPICFG Convenience alias for MPI4PY_BUILD_MPICFG.
Using scikit-build-core
TIP:
Set the MPI4PY_BUILD_BACKEND environment variable to "scikit-build-core" to use the scikit-build-core
build backend.
When using the scikit-build-core build backend, mpi4py delegates all of MPI build configuration to ‐
CMake’s FindMPI module. Besides the obvious advantage of cross-platform support, this delegation to CMake
may be convenient in build environments exposing vendor software stacks via intricate module systems.
Note however that mpi4py will not be able to look for MPI routines available beyond the MPI standard
version the MPI implementation advertises to support (via the MPI_VERSION and MPI_SUBVERSION macro
constants in the mpi.h header file), any missing MPI constant or symbol will prevent a successful build.
Using meson-python
TIP:
Set the MPI4PY_BUILD_BACKEND environment variable to "meson-python" to use the meson-python build
backend.
When using the meson-python build backend, mpi4py delegates build tasks to the Meson build system.
WARNING:
mpi4py support for the meson-python build backend is experimental. For the time being, users must set
the CC environment variable to the command or path corresponding to the mpicc C compiler wrapper.
Using pip
You can install the latest mpi4py release from its source distribution at PyPI using pip:
$ python -m pip install mpi4py
You can also install the in-development version with:
$ python -m pip install git+https://github.com/mpi4py/mpi4py
or:
$ python -m pip install https://github.com/mpi4py/mpi4py/tarball/master
NOTE:
Installing mpi4py from its source distribution (available at PyPI) or Git source code repository
(available at GitHub) requires a C compiler and a working MPI implementation with development headers
and libraries.
WARNING:
pip keeps previously built wheel files on its cache for future reuse. If you want to reinstall the
mpi4py package using a different or updated MPI implementation, you have to either first remove the
cached wheel file with:
$ python -m pip cache remove mpi4py
or ask pip to disable the cache:
$ python -m pip install --no-cache-dir mpi4py
Using conda
The conda-forge community provides ready-to-use binary packages from an ever growing collection of
software libraries built around the multi-platform conda package manager. Four MPI implementations are
available on conda-forge: Open MPI (Linux and macOS), MPICH (Linux and macOS), Intel MPI (Linux and
Windows) and Microsoft MPI (Windows). You can install mpi4py and your preferred MPI implementation using
the conda package manager:
• to use MPICH do:
$ conda install -c conda-forge mpi4py mpich
• to use Open MPI do:
$ conda install -c conda-forge mpi4py openmpi
• to use Intel MPI do:
$ conda install -c conda-forge mpi4py impi_rt
• to use Microsoft MPI do:
$ conda install -c conda-forge mpi4py msmpi
MPICH and many of its derivatives are ABI-compatible. You can provide the package specification
mpich=X.Y.*=external_* (where X and Y are the major and minor version numbers) to request the conda
package manager to use system-provided MPICH (or derivative) libraries. Similarly, you can provide the
package specification openmpi=X.Y.*=external_* to use system-provided Open MPI libraries.
The openmpi package on conda-forge has built-in CUDA support, but it is disabled by default. To enable
it, follow the instruction outlined during conda install. Additionally, UCX support is also available
once the ucx package is installed.
WARNING:
Binary conda-forge packages are built with a focus on compatibility. The MPICH and Open MPI packages
are build in a constrained environment with relatively dated OS images. Therefore, they may lack
support for high-performance features like cross-memory attach (XPMEM/CMA). In production scenarios,
it is recommended to use external (either custom-built or system-provided) MPI installations. See the
relevant conda-forge documentation about using external MPI libraries .
Linux
On Fedora Linux systems (as well as RHEL and their derivatives using the EPEL software repository), you
can install binary packages with the system package manager:
• using dnf and the mpich package:
$ sudo dnf install python3-mpi4py-mpich
• using dnf and the openmpi package:
$ sudo dnf install python3-mpi4py-openmpi
Please remember to load the correct MPI module for your chosen MPI implementation:
• for the mpich package do:
$ module load mpi/mpich-$(arch)
$ python -c "from mpi4py import MPI"
• for the openmpi package do:
$ module load mpi/openmpi-$(arch)
$ python -c "from mpi4py import MPI"
On Ubuntu Linux and Debian Linux systems, binary packages are available for installation using the system
package manager:
$ sudo apt install python3-mpi4py
Note that on Ubuntu/Debian systems, the mpi4py package uses Open MPI. To use MPICH, install the
libmpich-dev and python3-dev packages (and any other required development tools). Afterwards, install
mpi4py from sources using pip.
macOS
macOS users can install mpi4py using the Homebrew package manager:
$ brew install mpi4py
Note that the Homebrew mpi4py package uses Open MPI. Alternatively, install the mpich package and next
install mpi4py from sources using pip.
Windows
Windows users can install mpi4py from binary wheels hosted on the Python Package Index (PyPI) using pip:
$ python -m pip install mpi4py
The Windows wheels available on PyPI are specially crafted to work with either the Intel MPI or the ‐
Microsoft MPI runtime, therefore requiring a separate installation of any one of these packages.
Intel MPI is under active development and supports recent version of the MPI standard. Intel MPI can be
installed with pip (see the impi-rt package on PyPI), being therefore straightforward to get it up and
running within a Python environment. Intel MPI can also be installed system-wide as part of the Intel HPC
Toolkit for Windows or via standalone online/offline installers.
DEVELOPMENT
Prerequisites
You need to have the following software properly installed to develop MPI for Python:
• Python 3.6 or above.
• The Cython compiler.
• A working MPI implementation like MPICH or Open MPI, preferably supporting MPI-4 and built with
shared/dynamic libraries.
Optionally, consider installing the following packages:
• NumPy for enabling comprehensive testing of MPI communication.
• CuPy for enabling comprehensive testing with a GPU-aware MPI.
• Sphinx to build the documentation.
TIP:
Most routine development tasks like building, installing in editable mode, testing, and generating
documentation can be performed with the spin developer tool. Run spin at the top level source
directory for a list of available subcommands.
Building
MPI for Python uses setuptools-based build system that relies on the setup.py file. Some setuptools
commands (e.g., build) accept additional options:
--mpi= Lets you pass a section with MPI configuration within a special configuration file. Alternatively,
you can use the MPICFG environment variable.
--mpicc=
Specify the path or name of the mpicc C compiler wrapper. Alternatively, use the MPICC
environment variable.
--mpild=
Specify the full path or name for the MPI-aware C linker. Alternatively, use the MPILD
environment variable. If not set, the mpicc C compiler wrapper is used for linking.
--configure
Runs exhaustive tests for checking about missing MPI types, constants, and functions. This option
should be passed in order to build MPI for Python against old MPI-1, MPI-2, or MPI-3
implementations, possibly providing a subset of MPI-4.
If you use a MPI implementation providing a mpicc C compiler wrapper (e.g., MPICH or Open MPI), it will
be used for compilation and linking. This is the preferred and easiest way to build MPI for Python.
If mpicc is found in the executable search path (PATH environment variable), simply run the build
command:
$ python setup.py build
If mpicc is not in your search path or the compiler wrapper has a different name, you can run the build
command specifying its location, either via the --mpicc command option or using the MPICC environment
variable:
$ python setup.py build --mpicc=/path/to/mpicc
$ env MPICC=/path/to/mpicc python setup.py build
Alternatively, you can provide all the relevant information about your MPI implementation by editing the
mpi.cfg file located in the top level source directory. You can use the default section [mpi] or add a
new custom section, for example [vendor_mpi] (see the examples provided in the mpi.cfg file as a starting
point to write your own section):
[mpi]
include_dirs = /usr/local/mpi/include
libraries = mpi
library_dirs = /usr/local/mpi/lib
runtime_library_dirs = /usr/local/mpi/lib
[vendor_mpi]
include_dirs = /opt/mpi/include ...
libraries = mpi ...
library_dirs = /opt/mpi/lib ...
runtime_library_dirs = /opt/mpi/lib ...
...
and then run the build command specifying you custom configuration section:
$ python setup.py build --mpi=vendor_mpi
$ env MPICFG=vendor_mpi python setup.py build
Installing
MPI for Python can be installed in editable mode:
$ python -m pip install --editable .
After modifying Cython sources, an in-place rebuild is needed:
$ python setup.py build --inplace
Testing
To quickly test the installation:
$ mpiexec -n 5 python -m mpi4py.bench helloworld
Hello, World! I am process 0 of 5 on localhost.
Hello, World! I am process 1 of 5 on localhost.
Hello, World! I am process 2 of 5 on localhost.
Hello, World! I am process 3 of 5 on localhost.
Hello, World! I am process 4 of 5 on localhost.
$ mpiexec -n 5 python -m mpi4py.bench ringtest -l 10 -n 1048576
time for 10 loops = 0.00361614 seconds (5 processes, 1048576 bytes)
If you installed from a git clone or the source distribution, issuing at the command line:
$ mpiexec -n 5 python demo/helloworld.py
will launch a five-process run of the Python interpreter and run the demo script demo/helloworld.py from
the source distribution.
You can also run all the unittest scripts:
$ mpiexec -n 5 python test/main.py
or, if you have the pytest unit testing framework installed:
$ mpiexec -n 5 pytest
GUIDELINES
Fair play
Summary
This section defines Rules of Play for companies and outside developers that engage with the mpi4py
project. It covers:
• Restrictions on use of the mpi4py name.
• How and whether to publish a modified distribution.
• How to make us aware of patched versions.
After reading this section, companies and developers will know what kinds of behavior the mpi4py
developers and contributors would like to see, and which we consider troublesome, bothersome, and
unacceptable.
This document is a close adaptation of NumPy NEP 36.
Motivation
Occasionally, we learn of modified mpi4py versions and binary distributions circulated by outsiders.
These patched versions can cause problems to mpi4py users (see, e.g., mpi4py/mpi4py#508). When issues
like these arise, our developers waste time identifying the problematic release, locating alterations,
and determining an appropriate course of action.
In addition, packages on the Python Packaging Index are sometimes named such that users assume they are
sanctioned or maintained by the mpi4py developers. We wish to reduce the number of such incidents.
Scope
This document aims to define a minimal set of rules that, when followed, will be considered good-faith
efforts in line with the expectations of the mpi4py developers and contributors.
Our hope is that companies and outside developers who feel they need to modify mpi4py will first consider
contributing to the project, or use alternative mechanisms for patching and extending mpi4py.
When in doubt, please talk to us first. We may suggest an alternative; at minimum, we’ll be informed and
we may even grant an exception if deemed appropriate.
Fair play rules
1. Do not reuse the mpi4py name for projects not affiliated with the mpi4py project.
At time of writing, there are only a handful of mpi4py-named packages developed by the mpi4py project,
including mpi4py and mpi4py-fft. We ask that outside packages not include the phrase mpi4py, i.e.,
avoid names such as mycompany-mpi4py or mpi4py-mycompany.
To be clear, this rule only applies to modules (package names); it is perfectly acceptable to have a
submodule of your own package named mycompany.mpi4py.
2. Do not publish binary mpi4py wheels on PyPI (https://pypi.org/).
We ask companies and outside developers to not publish binary mpi4py wheels in the main Python Package
Index (https://pypi.org/) under names such mpi4py-mpich, mpi4py-openmpi, or mpi4py-vendor_mpi.
The usual approaches to build binary Python wheels involve the embedding of dependent shared
libraries. While such an approach may seem convenient and often is, in the particular case of MPI and
mpi4py it is ultimately harmful to end users. Embedding the MPI shared libraries would prevent the use
of external, system-provided MPI installations with hardware-specific optimizations and site-specific
tweaks.
The MPI Forum is currently discussing the standardization of a proposal for an Application Binary
Interface (ABI) for MPI, see [mpi-abi-paper] and [mpi-abi-issue]. Such standardization will allow for
any binary dependent on the MPI library to be used with multiple MPI backends. Once this proposal
becomes part of the MPI standard, the mpi4py project will consider publishing on PyPI binary wheels
capable of using any backend MPI implementation supporting the new MPI ABI specification. In the mean
time, mpi4py is currently distributing experimental MPI and mpi4py binary wheels on ‐
https://anaconda.org/mpi4py.
[mpi-abi-paper]
J. Hammond, L. Dalcin, E. Schnetter, M. Pérache, J. B. Besnard, J. Brown, G. Brito Gadeschi, S.
Byrne, J. Schuchart, and H. Zhou. MPI Application Binary Interface Standardization. EuroMPI 2023,
Bristol, UK, September 2023. https://doi.org/10.1145/3615318.3615319
[mpi-abi-issue]
MPI Forum GitHub Issue: MPI needs a standard ABI. ‐
https://github.com/mpi-forum/mpi-issues/issues/751
3. Do not republish modified versions of mpi4py.
Modified versions of mpi4py make it very difficult for the developers to address bug reports, since we
typically do not know which parts of mpi4py have been modified.
If you have to break this rule (and we implore you not to!), then make it clear in the __version__ tag
that you have modified mpi4py, e.g.:
>>> print(mpi4py.__version__)
'4.0.0+mycompany.13`
We understand that minor patches are often required to make a library work inside of a package
ecosystem. This is totally acceptable, but we ask that no substantive changes are made.
4. Do not extend or modify mpi4py’s API.
If you absolutely have to break the previous rule, please do not add additional functions to the
namespace, or modify the API of existing functions. Having additional functions exposed in distributed
versions is confusing for users and developers alike.
LICENSE
Copyright (c) 2025, Lisandro Dalcin
Redistribution and use in source and binary forms, with or without modification, are permitted provided
that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
the following disclaimer in the documentation and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or
promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
CHANGES
Release 4.0.3 [2025-02-13]
• Fix DLPack v1.0 support.
Release 4.0.2 [2025-02-01]
• Support MPI-4 features within Intel MPI 2021.14.
• Various fixes and updates to tests.
• Minor fixes to typing support.
• Minor fix to documentation.
Release 4.0.1 [2024-10-11]
• Update support for Python 3.13:
• Enable Cython 3.1 support for free-threaded CPython.
• Allow compiling Cython-generated C sources with the full Python C-API.
• Fix MPI DLL path workarounds on Windows after changes to locals().
• Enhancements to test suite:
• Support XML reports via unittest-xml-reporting.
• Add command line options to exclude tests by patterns and files.
• Refactor Python 2 code to use Python 3 constructs using pyupgrade.
• Miscellaneous:
• Minor and mostly inconsequential subclass fix in mpi4py.util.pkl5.
• Update compatibility workarounds for legacy MPICH 3.0 release.
Release 4.0.0 [2024-07-28]
• New features:
• Add support for the MPI-4.0 standard.
• Use large count MPI-4 routines.
• Add persistent collective communication.
• Add partitioned point-to-point communication.
• Add new communicator constructors.
• Add the Session class and its methods.
• Add support for the MPI-4.1 standard.
• Add non-destructive completion test for multiple requests.
• Add value-index datatype constructor.
• Add communicator/session buffer attach/detach/flush.
• Support for removal of error classes/codes/strings.
• Support for querying hardware resource information.
• Add preliminary support for the upcoming MPI-5.0 standard.
• User-level failure mitigation (ULFM).
• mpi4py.util.pool: New drop-in replacement for multiprocessing.pool.
• mpi4py.util.sync: New synchronization utilities.
• Add runtime check for mismatch between mpiexec and MPI library.
• Support scikit-build-core as an alternative build backend.
• Support meson-python as an alternative build backend.
• Enhancements:
• mpi4py.futures: Support for parallel tasks.
• mpi4py.futures: Report exception tracebacks in workers.
• mpi4py.util.pkl5: Add support for collective communication.
• Add methods Datatype.fromcode(), Datatype.tocode() and attributes Datatype.typestr, Datatype.typechar
to simplify NumPy interoperability for simple cases.
• Add methods Comm.Create_errhandler(), Win.Create_errhandler(), and File.Create_errhandler() to create
custom error handlers.
• Add support for pickle serialization of instances of MPI types. All instances of Datatype, Info, and
Status can be serialized. Instances of Op can be serialized only if created through mpi4py by calling
Op.Create(). Instances of other MPI types can be serialized only if they reference predefined
handles.
• Add handle attribute and fromhandle() class method to MPI classes to ease interoperability with
external code. The handle value is an unsigned integer guaranteed to fit on the platform’s uintptr_t
C type.
• Add lowercase free() method to MPI classes to ease MPI object deallocation and cleanup. This method
eventually attempts to call Free(), but only if the object’s MPI handle is not a null or predefined
handle, and such call is allowed within the World Model init/finalize.
• Backward-incompatible changes:
• Python 2 is no longer supported, Python 3.6+ is required, but typing stubs are supported for Python
3.8+.
• The Intracomm.Create_group() method is no longer defined in the base Comm class.
• Group.Compare() and Comm.Compare() are no longer class methods but instance methods. Existing codes
using the former class methods are expected to continue working.
• Group.Translate_ranks() is no longer a class method but an instance method. Existing codes using the
former class method are expected to continue working.
• The LB and UB datatypes are no longer available, use Datatype.Create_resized() instead.
• The HOST predefined attribute key is no longer available.
• The MPI.memory class has been renamed to MPI.buffer. The old name is still available as an alias to
the new name.
• The mpi4py.dl module is no longer available.
• The mpi4py.get_config function returns an empty dictionary.
• Miscellaneous:
• The project is now licensed under the BSD-3-Clause license. This change is fairly inconsequential for
users and distributors. It simply adds an additional clause against using contributor names for
promotional purposes without their consent.
• Add a new guidelines section to documentation laying out new fair play rules. These rules ask
companies and outside developers to refrain from reusing the mpi4py name in unaffiliated projects,
publishing binary mpi4py wheels on the main Python Package Index (PyPI), and distributing modified
versions with incompatible or extended API changes. The primary motivation of these rules is to avoid
fragmentation and end-user confusion.
Release 3.1.6 [2024-04-14]
WARNING:
This is the last release supporting Python 2.
• Fix various build issues.
Release 3.1.5 [2023-10-04]
WARNING:
This is the last release supporting Python 2.
• Rebuild C sources with Cython 0.29.36 to support Python 3.12.
Release 3.1.4 [2022-11-02]
WARNING:
This is the last release supporting Python 2.
• Rebuild C sources with Cython 0.29.32 to support Python 3.11.
• Fix contiguity check for DLPack and CAI buffers.
• Workaround build failures with setuptools v60.
Release 3.1.3 [2021-11-25]
WARNING:
This is the last release supporting Python 2.
• Add missing support for MPI.BOTTOM to generalized all-to-all collectives.
Release 3.1.2 [2021-11-04]
WARNING:
This is the last release supporting Python 2.
• mpi4py.futures: Add _max_workers property to MPIPoolExecutor.
• mpi4py.util.dtlib: Fix computation of alignment for predefined datatypes.
• mpi4py.util.pkl5: Fix deadlock when using ssend() + mprobe().
• mpi4py.util.pkl5: Add environment variable MPI4PY_PICKLE_THRESHOLD.
• mpi4py.rc: Interpret "y" and "n" strings as boolean values.
• Fix/add typemap/typestr for MPI.WCHAR/MPI.COUNT datatypes.
• Minor fixes and additions to documentation.
• Minor fixes to typing support.
• Support for local version identifier (PEP-440).
Release 3.1.1 [2021-08-14]
WARNING:
This is the last release supporting Python 2.
• Fix typo in Requires-Python package metadata.
• Regenerate C sources with Cython 0.29.24.
Release 3.1.0 [2021-08-12]
WARNING:
This is the last release supporting Python 2.
• New features:
• mpi4py.util: New package collecting miscellaneous utilities.
• Enhancements:
• Add pickle-based Request.waitsome() and Request.testsome().
• Add lowercase methods Request.get_status() and Request.cancel().
• Support for passing Python GPU arrays compliant with the DLPack data interchange mechanism (link) and
the __cuda_array_interface__ (CAI) standard (link) to uppercase methods. This support requires that
mpi4py is built against CUDA-aware MPI implementations. This feature is currently experimental and
subject to future changes.
• mpi4py.futures: Add support for initializers and canceling futures at shutdown. Environment
variables names now follow the pattern MPI4PY_FUTURES_*, the previous MPI4PY_* names are deprecated.
• Add type annotations to Cython code. The first line of the docstring of functions and methods
displays a signature including type annotations.
• Add companion stub files to support type checkers.
• Support for weak references.
• Miscellaneous:
• Add a new mpi4py publication (link) to the citation listing.
Release 3.0.3 [2019-11-04]
• Regenerate Cython wrappers to support Python 3.8.
Release 3.0.2 [2019-06-11]
• Bug fixes:
• Fix handling of readonly buffers in support for Python 2 legacy buffer interface. The issue triggers
only when using a buffer-like object that is readonly and does not export the new Python 3 buffer
interface.
• Fix build issues with Open MPI 4.0.x series related to removal of many MPI-1 symbols deprecated in
MPI-2 and removed in MPI-3.
• Minor documentation fixes.
Release 3.0.1 [2019-02-15]
• Bug fixes:
• Fix Comm.scatter() and other collectives corrupting input send list. Add safety measures to prevent
related issues in global reduction operations.
• Fix error-checking code for counts in Op.Reduce_local().
• Enhancements:
• Map size-specific Python/NumPy typecodes to MPI datatypes.
• Allow partial specification of target list/tuple arguments in the various Win RMA methods.
• Workaround for removal of MPI_{LB|UB} in Open MPI 4.0.
• Support for Microsoft MPI v10.0.
Release 3.0.0 [2017-11-08]
• New features:
• mpi4py.futures: Execute computations asynchronously using a pool of MPI processes. This package is
based on concurrent.futures from the Python standard library.
• mpi4py.run: Run Python code and abort execution in case of unhandled exceptions to prevent deadlocks.
• mpi4py.bench: Run basic MPI benchmarks and tests.
• Enhancements:
• Lowercase, pickle-based collective communication calls are now thread-safe through the use of
fine-grained locking.
• The MPI module now exposes a memory type which is a lightweight variant of the builtin memoryview
type, but exposes both the legacy Python 2 and the modern Python 3 buffer interface under a Python 2
runtime.
• The MPI.Comm.Alltoallw() method now uses count=1 and displ=0 as defaults, assuming that messages are
specified through user-defined datatypes.
• The Request.Wait[all]() methods now return True to match the interface of Request.Test[all]().
• The Win class now implements the Python buffer interface.
• Backward-incompatible changes:
• The buf argument of the MPI.Comm.recv() method is deprecated, passing anything but None emits a
warning.
• The MPI.Win.memory property was removed, use the MPI.Win.tomemory() method instead.
• Executing python -m mpi4py in the command line is now equivalent to python -m mpi4py.run. For the
former behavior, use python -m mpi4py.bench.
• Python 2.6 and 3.2 are no longer supported. The mpi4py.MPI module may still build and partially work,
but other pure-Python modules under the mpi4py namespace will not.
• Windows: Remove support for legacy MPICH2, Open MPI, and DeinoMPI.
Release 2.0.0 [2015-10-18]
• Support for MPI-3 features.
• Matched probes and receives.
• Nonblocking collectives.
• Neighborhood collectives.
• New communicator constructors.
• Request-based RMA operations.
• New RMA communication and synchronisation calls.
• New window constructors.
• New datatype constructor.
• New C++ boolean and floating complex datatypes.
• Support for MPI-2 features not included in previous releases.
• Generalized All-to-All collective (Comm.Alltoallw())
• User-defined data representations (Register_datarep())
• New scalable implementation of reduction operations for Python objects. This code is based on binomial
tree algorithms using point-to-point communication and duplicated communicator contexts. To disable
this feature, use mpi4py.rc.fast_reduce = False.
• Backward-incompatible changes:
• Python 2.4, 2.5, 3.0 and 3.1 are no longer supported.
• Default MPI error handling policies are overridden. After import, mpi4py sets the ERRORS_RETURN error
handler in COMM_SELF and COMM_WORLD, as well as any new Comm, Win, or File instance created through
mpi4py, thus effectively ignoring the MPI rules about error handler inheritance. This way, MPI
errors translate to Python exceptions. To disable this behavior and use the standard MPI error
handling rules, use mpi4py.rc.errors = 'default'.
• Change signature of all send methods, dest is a required argument.
• Change signature of all receive and probe methods, source defaults to ANY_SOURCE, tag defaults to
ANY_TAG.
• Change signature of send lowercase-spelling methods, obj arguments are not mandatory.
• Change signature of recv lowercase-spelling methods, renamed ‘obj’ arguments to ‘buf’.
• Change Request.Waitsome() and Request.Testsome() to return None or list.
• Change signature of all lowercase-spelling collectives, sendobj arguments are now mandatory, recvobj
arguments were removed.
• Reduction operations MAXLOC and MINLOC are no longer special-cased in lowercase-spelling methods
Comm.[all]reduce() and Comm.[ex]scan(), the input object must be specified as a tuple (obj,
location).
• Change signature of name publishing functions. The new signatures are Publish_name(service_name,
port_name, info=INFO_NULL) and Unpublish_name(service_name, port_name, info=INFO_NULL)`.
• Win instances now cache Python objects exposing memory by keeping references instead of using MPI
attribute caching.
• Change signature of Win.Lock(). The new signature is Win.Lock(rank, lock_type=LOCK_EXCLUSIVE,
assertion=0).
• Move Cartcomm.Map() to Intracomm.Cart_map().
• Move Graphcomm.Map() to Intracomm.Graph_map().
• Remove the mpi4py.MPE module.
• Rename the Cython definition file for use with cimport statement from mpi_c.pxd to libmpi.pxd.
Release 1.3.1 [2013-08-07]
• Regenerate C wrappers with Cython 0.19.1 to support Python 3.3.
• Install *.pxd files in <site-packages>/mpi4py to ease the support for Cython’s cimport statement in
code requiring to access mpi4py internals.
• As a side-effect of using Cython 0.19.1, ancient Python 2.3 is no longer supported. If you really need
it, you can install an older Cython and run python setup.py build_src --force.
Release 1.3 [2012-01-20]
• Now Comm.recv() accept a buffer to receive the message.
• Add Comm.irecv() and Request.{wait|test}[any|all]().
• Add Intracomm.Spawn_multiple().
• Better buffer handling for PEP 3118 and legacy buffer interfaces.
• Add support for attribute attribute caching on communicators, datatypes and windows.
• Install MPI-enabled Python interpreter as <path>/mpi4py/bin/python-mpi.
• Windows: Support for building with Open MPI.
Release 1.2.2 [2010-09-13]
• Add mpi4py.get_config() to retrieve information (compiler wrappers, includes, libraries, etc) about the
MPI implementation employed to build mpi4py.
• Workaround Python libraries with missing GILState-related API calls in case of non-threaded Python
builds.
• Windows: look for MPICH2, DeinoMPI, Microsoft HPC Pack at their default install locations under
%ProgramFiles.
• MPE: fix hacks related to old API’s, these hacks are broken when MPE is built with a MPI
implementations other than MPICH2.
• HP-MPI: fix for missing Fortran datatypes, use dlopen() to load the MPI shared library before
MPI_Init()
• Many distutils-related fixes, cleanup, and enhancements, better logics to find MPI compiler wrappers.
• Support for pip install mpi4py.
Release 1.2.1 [2010-02-26]
• Fix declaration in Cython include file. This declaration, while valid for Cython, broke the
simple-minded parsing used in conf/mpidistutils.py to implement configure-tests for availability of MPI
symbols.
• Update SWIG support and make it compatible with Python 3. Also generate an warning for SWIG < 1.3.28.
• Fix distutils-related issues in Mac OS X. Now ARCHFLAGS environment variable is honored of all Python’s
config/Makefile variables.
• Fix issues with Open MPI < 1.4.2 related to error checking and MPI_XXX_NULL handles.
Release 1.2 [2009-12-29]
• Automatic MPI datatype discovery for NumPy arrays and PEP-3118 buffers. Now buffer-like objects can be
messaged directly, it is no longer required to explicitly pass a 2/3-list/tuple like [data,
MPI.DOUBLE], or [data, count, MPI.DOUBLE]. Only basic types are supported, i.e., all C/C99-native
signed/unsigned integral types and single/double precision real/complex floating types. Many thanks to
Eilif Muller for the initial feedback.
• Nonblocking send of pickled Python objects. Many thanks to Andreas Kloeckner for the initial patch and
enlightening discussion about this enhancement.
• Request instances now hold a reference to the Python object exposing the buffer involved in
point-to-point communication or parallel I/O. Many thanks to Andreas Kloeckner for the initial
feedback.
• Support for logging of user-defined states and events using MPE. Runtime (i.e., without requiring a
recompile!) activation of logging of all MPI calls is supported in POSIX platforms implementing
dlopen().
• Support for all the new features in MPI-2.2 (new C99 and F90 datatypes, distributed graph topology,
local reduction operation, and other minor enhancements).
• Fix the annoying issues related to Open MPI and Python dynamic loading of extension modules in
platforms supporting dlopen().
• Fix SLURM dynamic loading issues on SiCortex. Many thanks to Ian Langmore for providing me shell
access.
Release 1.1.0 [2009-06-06]
• Fix bug in Comm.Iprobe() that caused segfaults as Python C-API calls were issued with the GIL released
(issue #2).
• Add Comm.bsend() and Comm.ssend() for buffered and synchronous send semantics when communicating
general Python objects.
• Now the call Info.Get(key) return a single value (i.e, instead of a 2-tuple); this value is None if key
is not in the Info object, or a string otherwise. Previously, the call redundantly returned (None,
False) for missing key-value pairs; None is enough to signal a missing entry.
• Add support for parametrized Fortran datatypes.
• Add support for decoding user-defined datatypes.
• Add support for user-defined reduction operations on memory buffers. However, at most 16 user-defined
reduction operations can be created. Ask the author for more room if you need it.
Release 1.0.0 [2009-03-20]
This is the fist release of the all-new, Cython-based, implementation of MPI for Python. Unfortunately,
this implementation is not backward-compatible with the previous one. The list below summarizes the more
important changes that can impact user codes.
• Some communication calls had overloaded functionality. Now there is a clear distinction between
communication of general Python object with pickle, and (fast, near C-speed) communication of
buffer-like objects (e.g., NumPy arrays).
• for communicating general Python objects, you have to use all-lowercase methods, like send(), recv(),
bcast(), etc.
• for communicating array data, you have to use Send(), Recv(), Bcast(), etc. methods. Buffer arguments
to these calls must be explicitly specified by using a 2/3-list/tuple like [data, MPI.DOUBLE], or
[data, count, MPI.DOUBLE] (the former one uses the byte-size of data and the extent of the MPI
datatype to define the count).
• Indexing a communicator with an integer returned a special object associating the communication with a
target rank, alleviating you from specifying source/destination/root arguments in point-to-point and
collective communications. This functionality is no longer available, expressions like:
MPI.COMM_WORLD[0].Send(...)
MPI.COMM_WORLD[0].Recv(...)
MPI.COMM_WORLD[0].Bcast(...)
have to be replaced by:
MPI.COMM_WORLD.Send(..., dest=0)
MPI.COMM_WORLD.Recv(..., source=0)
MPI.COMM_WORLD.Bcast(..., root=0)
• Automatic MPI initialization (i.e., at import time) requests the maximum level of MPI thread support
(i.e., it is done by calling MPI_Init_thread() and passing MPI_THREAD_MULTIPLE). In case you need to
change this behavior, you can tweak the contents of the mpi4py.rc module.
• In order to obtain the values of predefined attributes attached to the world communicator, now you have
to use the Get_attr() method on the MPI.COMM_WORLD instance:
tag_ub = MPI.COMM_WORLD.Get_attr(MPI.TAG_UB)
• In the previous implementation, MPI.COMM_WORLD and MPI.COMM_SELF were associated to duplicates of the
(C-level) MPI_COMM_WORLD and MPI_COMM_SELF predefined communicator handles. Now this is no longer the
case, MPI.COMM_WORLD and MPI.COMM_SELF proxies the actual MPI_COMM_WORLD and MPI_COMM_SELF handles.
• Convenience aliases MPI.WORLD and MPI.SELF were removed. Use instead MPI.COMM_WORLD and MPI.COMM_SELF.
• Convenience constants MPI.WORLD_SIZE and MPI.WORLD_RANK were removed. Use instead
MPI.COMM_WORLD.Get_size() and MPI.COMM_WORLD.Get_rank().
AUTHOR
Lisandro Dalcin
COPYRIGHT
2025, Lisandro Dalcin
4.0 March 15, 2025 MPI4PY(3)