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===================
Python processing
===================
:Author: R Oudkerk
:Contact: roudkerk at users.berlios.de
:Url: http://developer.berlios.de/projects/pyprocessing
:Version: |version|
:Licence: BSD Licence
`processing` is a package for the Python language which supports the
spawning of processes using the API of the standard library's
`threading` module. It runs on both Unix and Windows.
Features:
* Objects can be transferred between processes using pipes or
multi-producer/multi-consumer queues.
* Objects can be shared between processes using a server process or
(for simple data) shared memory.
* Equivalents of all the synchronization primitives in `threading`
are available.
* A `Pool` class makes it easy to submit tasks to a pool of worker
processes.
Links
=====
* `Documentation <./doc/index.html>`_
* `Installation instructions <./doc/INSTALL.html>`_
* `Changelog <./doc/CHANGES.html>`_
* `Acknowledgments <./doc/THANKS.html>`_
* `BSD Licence <./doc/COPYING.html>`_
The project is hosted at
* http://developer.berlios.de/projects/pyprocessing
The package can be downloaded from
* http://developer.berlios.de/project/filelist.php?group_id=9001 or
* http://pypi.python.org/pypi/processing
Examples
========
The `processing.Process` class follows the API of `threading.Thread`.
For example ::
from processing import Process, Queue
def f(q):
q.put('hello world')
if __name__ == '__main__':
q = Queue()
p = Process(target=f, args=[q])
p.start()
print q.get()
p.join()
Synchronization primitives like locks, semaphores and conditions are
available, for example ::
>>> from processing import Condition
>>> c = Condition()
>>> print c
), 0>
>>> c.acquire()
True
>>> print c
), 0>
One can also use a manager to create shared objects either in shared
memory or in a server process, for example ::
>>> from processing import Manager
>>> manager = Manager()
>>> l = manager.list(range(10))
>>> l.reverse()
>>> print l
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
>>> print repr(l)
Tasks can be offloaded to a pool of worker processes in various ways,
for example ::
>>> from processing import Pool
>>> def f(x): return x*x
...
>>> p = Pool(4)
>>> result = p.mapAsync(f, range(10))
>>> print result.get(timeout=1)
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
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