New submission from Maciej Fijalkowski: This is what the current documentation says: -O Turn on basic optimizations. This changes the filename extension for compiled (bytecode) files from .pyc to .pyo. See also PYTHONOPTIMIZE. -OO Discard docstrings in addition to the -O optimizations. As far as I know, the only "optimization" that's done is removal of __debug__ sections and assert statements and has been like this for years. Maybe it should say so "-O does not do any optimizations, only removes assert statement" or so. ---------- assignee: docs@python components: Documentation messages: 182365 nosy: docs@python, fijall priority: normal severity: normal status: open title: Improve -O docs type: behavior _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Ramchandra Apte added the comment: It should also add that in the future, more optimizations may be added i.e. a peephole optimizer, etc. ---------- nosy: +Ramchandra Apte _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Maciej Fijalkowski added the comment: There were not for at least 10 years. I would also be the first one to strongly object adding optimizations only under -O, because that already changes semantics. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Nick Coghlan added the comment: Ramchandra, as it turns out, if we deem an optimization semantically safe, we do it without -O, it we deem it unsafe, we don't do it at all. Thus, the real effect is to remove assert statements and optimise code as if "__debug__" was replaced by a literal zero (effectively). So a more meaningful description would be: -O Removes assert statements and any code conditional on the value of __debug__. This changes the filename extension for compiled (bytecode) files from .pyc to .pyo. See also PYTHONOPTIMIZE. ---------- nosy: +ncoghlan _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Changes by Brett Cannon <brett@python.org>: ---------- nosy: +brett.cannon _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Terry J. Reedy added the comment: I agree that we should document exactly what is now. Patch replaces first sentence with Nick's. It is against 3.4, but should be identical for all versions. Maciej, thanks for reminding us to finally fix this. ---------- keywords: +patch nosy: +terry.reedy versions: +Python 2.7, Python 3.2, Python 3.3, Python 3.4 Added file: http://bugs.python.org/file29165/issue17232.diff _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Antoine Pitrou added the comment: Should probably be "Remove", not "Removes" (we use infinitives to describe the actions undertaken by a command / option / method ...). ---------- nosy: +pitrou _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Terry J. Reedy added the comment: Perhaps '__debug__' need markup, but if so, I don't know how. And I agree with Antoine. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Nick Coghlan added the comment: +1 for Remove instead of Removes For the online docs, :const:`__debug__` should work (resolving to http://docs.python.org/3/library/constants.html#__debug__, which is currently described using some slightly brain-bending phrasing) We should also tweak the output of "python -h" (the help string is in ./Modules/main.c) ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Eli Bendersky added the comment: +1, I've been bothered by this description of "optimization" for a long time. Terry's patch LGTM ---------- nosy: +eli.bendersky _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Maciej Fijalkowski added the comment: Also IMO -OO should stop talking about optimizations. Maybe "Do what -O does and discard docstrings"? ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Terry J. Reedy added the comment: I added :const: and tweaked -OO entry and -h startup display. Tested new html and python_d -h. Any other comments before I apply? ---------- assignee: docs@python -> terry.reedy Added file: http://bugs.python.org/file29392/17232-O.diff _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Antoine Pitrou added the comment: There's a typo in your patch: +-O : remove assert and __debug__-dependent statements; change .py\n\ + to .pyo; also PYTHONOPTIMIZE=x\n\ should say ".pyc", not ".py". ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Antoine Pitrou added the comment: Also, in 3.2 and higher I'm not sure there's a point in mentioning pyc/pyo files; they're all shelved in __pycache__ now. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Nick Coghlan added the comment: On Tue, Mar 12, 2013 at 1:18 PM, Antoine Pitrou <report@bugs.python.org> wrote:
Antoine Pitrou added the comment:
Also, in 3.2 and higher I'm not sure there's a point in mentioning pyc/pyo files; they're all shelved in __pycache__ now.
It still makes a difference for bytecode-only files, which aren't in __pycache__ Cheers, Nick. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Terry J. Reedy added the comment: I corrected my copy of the .diff. Since this issue is so far focused on removing the false optimize claim, hiding .pyx info is a new sub-issue. I will follow whatever the consensus is, but since this is a cpython-specific doc and help, I would prefer to give complete info. In fact, I would like to add 'stored in __pycache__' or even 'hidden away in __pycache__', the latter to suggest that most people should generally forget about them. On Windows, _xxx files like __pycache__ appear in both Command Prompt dir and Explorer file listings, so beginners need to known that __cache__ is both normal and ignorable. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Ezio Melotti added the comment: I left a review on rietveld. ---------- nosy: +ezio.melotti stage: -> patch review _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Ezio Melotti added the comment: Terry, do you want to update your patch? ---------- versions: -Python 3.2 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Changes by Martin Panter <vadmium+py@gmail.com>: ---------- nosy: +vadmium _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Changes by Arfrever Frehtes Taifersar Arahesis <Arfrever.FTA@GMail.Com>: ---------- nosy: +Arfrever _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Changes by Serhiy Storchaka <storchaka@gmail.com>: ---------- stage: patch review -> needs patch versions: +Python 3.5 -Python 3.3 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Changes by Berker Peksag <berker.peksag@gmail.com>: ---------- nosy: +berker.peksag _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Changes by STINNER Victor <victor.stinner@gmail.com>: ---------- nosy: +haypo _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17232> _______________________________________
Cheryl Sabella <chekat2@gmail.com> added the comment: Should I make a pull request for Terry's last patch? ---------- nosy: +csabella _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Terry J. Reedy <tjreedy@udel.edu> added the comment: Cheryl: yes, with changes in responses to Ezio's review. Nick or Antoine: has there been any change to meaning of -O or -OO that I am not remembering? ---------- versions: +Python 3.6, Python 3.7, Python 3.8 -Python 3.4, Python 3.5 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Nick Coghlan <ncoghlan@gmail.com> added the comment: We don't change the extension on optimised pyc files any more, we add an optimisation marker to the name without changing the file extension: https://www.python.org/dev/peps/pep-0488/ (This means `-O` and `-OO` don't tread on each other any more) ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Change by Cheryl Sabella <chekat2@gmail.com>: ---------- pull_requests: +5616 stage: needs patch -> patch review _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Cheryl Sabella <chekat2@gmail.com> added the comment: I've made a PR and tried to integrate the changes from PEP 488. ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Terry J. Reedy <tjreedy@udel.edu> added the comment: New changeset 186b606d8a2ea4fd51b7286813302c8e8c7006cc by Terry Jan Reedy (Cheryl Sabella) in branch 'master': bpo-17232: Clarify docs for -O and -OO command line options (#5839) https://github.com/python/cpython/commit/186b606d8a2ea4fd51b7286813302c8e8c7... ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Change by miss-islington <mariatta.wijaya+miss-islington@gmail.com>: ---------- pull_requests: +5641 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Change by miss-islington <mariatta.wijaya+miss-islington@gmail.com>: ---------- pull_requests: +5642 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
miss-islington <mariatta.wijaya+miss-islington@gmail.com> added the comment: New changeset b5655f3d187084579ff389dbd8734742a8b66cbc by Miss Islington (bot) in branch '3.7': bpo-17232: Clarify docs for -O and -OO command line options (GH-5839) https://github.com/python/cpython/commit/b5655f3d187084579ff389dbd8734742a8b... ---------- nosy: +miss-islington _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
miss-islington <mariatta.wijaya+miss-islington@gmail.com> added the comment: New changeset fc9471a888f373aedff3c118ae9a6cbf2037bd7c by Miss Islington (bot) in branch '3.6': bpo-17232: Clarify docs for -O and -OO command line options (GH-5839) https://github.com/python/cpython/commit/fc9471a888f373aedff3c118ae9a6cbf203... ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
Change by Terry J. Reedy <tjreedy@udel.edu>: ---------- resolution: -> fixed stage: patch review -> resolved status: open -> closed _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17232> _______________________________________
participants (15)
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Antoine Pitrou -
Arfrever Frehtes Taifersar Arahesis
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Berker Peksag
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Brett Cannon
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Cheryl Sabella
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Eli Bendersky
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Ezio Melotti
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Maciej Fijalkowski
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Martin Panter
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miss-islington
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Nick Coghlan
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Ramchandra Apte
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Serhiy Storchaka
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STINNER Victor
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Terry J. Reedy