[issue24475] The docs never define what a pool "task" is
New submission from Zahari Dim: See: http://stackoverflow.com/questions/30943161/multiprocessing-pool-with-maxtas... The documentation never makes clear what a "task" in the context of Pool.map. At best, it says: "This method chops the iterable into a number of chunks which it submits to the process pool as separate tasks. The (approximate) size of these chunks can be specified by setting chunksize to a positive integer." in the map documentation. However it does not say how this chunks are calculated by default, making the maxtasksperchild argument not very useful. The fact that a function evaluated by map is not a "task" should be much clearer in the documentation. Also, in the examples, such as: with multiprocessing.Pool(PROCESSES) as pool: # # Tests # TASKS = [(mul, (i, 7)) for i in range(10)] + \ [(plus, (i, 8)) for i in range(10)] results = [pool.apply_async(calculate, t) for t in TASKS] imap_it = pool.imap(calculatestar, TASKS) imap_unordered_it = pool.imap_unordered(calculatestar, TASKS) TASKS are not actually "tasks" but rather "task groups". ---------- assignee: docs@python components: Documentation messages: 245509 nosy: Zahari.Dim, docs@python priority: normal severity: normal status: open title: The docs never define what a pool "task" is versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4, Python 3.5, Python 3.6 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24475> _______________________________________
Changes by Ned Deily <nad@acm.org>: ---------- nosy: +davin, sbt versions: -Python 3.2, Python 3.3 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24475> _______________________________________
Daniel Neuberger added the comment: I second this. I was definitely confused at first and it took me a little while of googling to realize that jobs are not what one (at least me) would intuitively think they are. ---------- nosy: +Daniel Neuberger _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24475> _______________________________________
Changes by Davin Potts <python@discontinuity.net>: ---------- type: -> enhancement _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24475> _______________________________________
Change by Irit Katriel <iritkatriel@yahoo.com>: ---------- components: +Library (Lib) versions: +Python 3.10, Python 3.11, Python 3.8, Python 3.9 -Python 2.7, Python 3.4, Python 3.5, Python 3.6 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue24475> _______________________________________
participants (5)
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Daniel Neuberger
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Davin Potts
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Irit Katriel
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Ned Deily
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Zahari Dim