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A common interface for parallel processing pools.

Project Description

A common interface to parallel processing pools.

Enables easy switching between serial execution, multiprocessing, and MPI by providing a common interface.


If you can write your code following the MapReduce programming model, you can trivially parallelize it using The Schwimmbad. For example, if you can structure your code so that a ‘worker’ function operates on elements from a list of tasks, like this:

def worker(task):
    # do something with the task!
    return task**2

def main():
    tasks = range(100)
    results = map(worker, tasks)

if __name__ == "__main__":

with a few added lines of code, you can make it runnable with multiprocessing and MPI at the switch of a command-line flag:

import schwimmbad

def worker(task):
    # do something with the task!
    return task**2

def main(pool):
    tasks = range(100)
    results =, tasks)

if __name__ == "__main__":
    from argparse import ArgumentParser
    parser = ArgumentParser(description="")

    group = parser.add_mutually_exclusive_group()
    group.add_argument("--ncores", dest="n_cores", default=1,
                       type=int, help="Number of processes (uses multiprocessing).")
    group.add_argument("--mpi", dest="mpi", default=False,
                       action="store_true", help="Run with MPI.")
    args = parser.parse_args()

    pool = schwimmbad.choose_pool(mpi=args.mpi, processes=args.n_cores)


The easiest way to install is via pip:

pip install schwimmbad

The project is also installable by cloning or downloading the source and using the standard:

python install


  • six
  • mpi4py (optional - needed for MPI pool support)


Copyright 2016 Adrian Price-Whelan.

schwimmbad is free software made available under the MIT License. For details see the LICENSE file.

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File Name & Checksum SHA256 Checksum Help Version File Type Upload Date
schwimmbad-0.2.1.tar.gz (9.5 kB) Copy SHA256 Checksum SHA256 Source Sep 23, 2016

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