[issue11957] re.sub confusion between count and flags args

Jakub Wilk added the comment: +raise TypeError("sub() takes from 2 to 4 positional arguments " +"but %d were given" % (4 + len(args))) It's actually 3 to 5 for sub() and subn(). -- ___ Python tracker <

[issue11957] re.sub confusion between count and flags args

Changes by Jakub Wilk : -- nosy: +jwilk ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org

[issue11957] re.sub confusion between count and flags args

Serhiy Storchaka added the comment: Victor, I borrowed Guido's time machine and wrote patches implementing both your suggestions a half year ago. -- ___ Python tracker ___ _

[issue11957] re.sub confusion between count and flags args

STINNER Victor added the comment: My issue #30072 has been marked as a duplicate of this one. Copy of my msg291650: The re API seems commonly misused. Example passing a re flag to re.sub(): >>> re.sub("A", "B", "ahah", re.I) 'ahah' No error, no warning, but it doesn't work. Oh, sub has 5 para

[issue11957] re.sub confusion between count and flags args

Changes by Serhiy Storchaka : Added file: http://bugs.python.org/file44826/re_deprecate_positional_count.patch ___ Python tracker ___ ___ Pyth

[issue11957] re.sub confusion between count and flags args

Serhiy Storchaka added the comment: Here are two alternative patches. The first patch checks if count or maxsplit arguments are re.RegexFlag and raise TypeError if it is true. This makes misusing flags fail fast. The second patch deprecates passing count and maxsplit arguments as positional ar

[issue11957] re.sub confusion between count and flags args

Roundup Robot added the comment: New changeset 216e8b809e4e by Serhiy Storchaka in branch '3.5': Issue #11957: Restored re tests for passing count and maxsplit as positional https://hg.python.org/cpython/rev/216e8b809e4e New changeset b39b09290718 by Serhiy Storchaka in branch '3.6': Issue #1195

[issue11957] re.sub confusion between count and flags args

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[issue11957] re.sub confusion between count and flags args

Changes by Serhiy Storchaka : -- dependencies: +Add IntFlags ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: ht

[issue11957] re.sub confusion between count and flags args

Serhiy Storchaka added the comment: I think that the enum solution is worth pursuing, and that we need general class which represents the set of specified named flags. I'm working on implementation of enum.IntFlags. -- ___ Python tracker

[issue11957] re.sub confusion between count and flags args

Ezio Melotti added the comment: I agree about 767fd62b59a9, there should be tests for args passed both by position and as keyword args. Serhiy, do you think the enum solution is worth pursuing, or is it better to just turn those args to keyword-only (after a proper deprecation process)? -

[issue11957] re.sub confusion between count and flags args

Serhiy Storchaka added the comment: And again about patch_11957. I afraid that testing isinstance(count, sre_constants.BaseFlags) on every re.sub() call will hit performance too. -- ___ Python tracker

[issue11957] re.sub confusion between count and flags args

Serhiy Storchaka added the comment: As for 767fd62b59a9, I doubt that changing positional arguments to keyword argumennts in tests is justified. This can hide a bug. -- ___ Python tracker _

[issue11957] re.sub confusion between count and flags args

Serhiy Storchaka added the comment: Thank you for your patch Valentina. But it makes flags combinations not pickleable. >>> import re, pickle >>> pickle.dumps(re.I|re.S, 3) Traceback (most recent call last): File "", line 1, in _pickle.PicklingError: Can't pickle : attribute lookup SubFlag

[issue11957] re.sub confusion between count and flags args

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[issue11957] re.sub confusion between count and flags args

STINNER Victor added the comment: Confusion between count/maxplit and count parameters is common, duplicated issues: * Issue #22760 * Issue #17663 * Issue #15537 * Issue #12875 * Issue #12078 * Issue #11947 See also issue #13385 which proposed an explicit "re.NOFLAGS flag". -- __

[issue11957] re.sub confusion between count and flags args

STINNER Victor added the comment: I suggest to make the 2 last parameters of re.sub(), re.subn() and re.split() parameters as keyword-only. It will break applications using count and maxsplit parameters as index parameters, but it's easy to fix these applications if they want to support also P

[issue11957] re.sub confusion between count and flags args

Roundup Robot added the comment: New changeset 767fd62b59a9 by Victor Stinner in branch 'default': Issue #11957: Explicit parameter name when calling re.split() and re.sub() https://hg.python.org/cpython/rev/767fd62b59a9 -- nosy: +python-dev ___ Pytho

[issue11957] re.sub confusion between count and flags args

Changes by Valentina Mukhamedzhanova : Added file: http://bugs.python.org/file30821/patch_11957 ___ Python tracker ___ ___ Python-bugs-list ma

[issue11957] re.sub confusion between count and flags args

Changes by Valentina Mukhamedzhanova : Removed file: http://bugs.python.org/file30813/patch_11957 ___ Python tracker ___ ___ Python-bugs-list

[issue11957] re.sub confusion between count and flags args

Changes by Valentina Mukhamedzhanova : Added file: http://bugs.python.org/file30813/patch_11957 ___ Python tracker ___ ___ Python-bugs-list ma

[issue11957] re.sub confusion between count and flags args

Changes by Valentina Mukhamedzhanova : Removed file: http://bugs.python.org/file30801/patch_11957 ___ Python tracker ___ ___ Python-bugs-list

[issue11957] re.sub confusion between count and flags args

Valentina Mukhamedzhanova added the comment: Please see my patch, I have changed flags to be instances of IntEnum and added a check to re.sub, re.subn and re.split. The patch contains some tests. This solution also allowed me to discover several bugs in the standard library, and I am going to

[issue11957] re.sub confusion between count and flags args

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[issue11957] re.sub confusion between count and flags args

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[issue11957] re.sub confusion between count and flags args

Ezio Melotti added the comment: The change would still be backwards compatible (even though inspect.signature and similar functions might return something different). Note that I'm not saying that's the best option, but it should be doable. -- ___

[issue11957] re.sub confusion between count and flags args

Mike Milkin added the comment: We could do that but we would be changing the signature before adding the warning -- ___ Python tracker ___ __

[issue11957] re.sub confusion between count and flags args

Ezio Melotti added the comment: Can't you use *args and **kwargs and then raise a deprecation warning if count and/or flags are in args? Even if enums are merged in, there might still be issues depending on their implementation. -- ___ Python tracke

[issue11957] re.sub confusion between count and flags args

Mike Milkin added the comment: There is no sane way to issue a warning without changing the signature and we don't want to change the signature without issuing a deprecation warning for the function, so sadly option 3 is the only way for this to work, (Im going to not touch this till ENUMS are

[issue11957] re.sub confusion between count and flags args

Mike Milkin added the comment: I like option #2, and I was thinking of working on it today, poke me if anyone has a problem with this. -- nosy: +mmilkin ___ Python tracker ___ _

[issue11957] re.sub confusion between count and flags args

Changes by Ezio Melotti : -- type: -> enhancement versions: +Python 3.4 -Python 3.1, Python 3.2 ___ Python tracker ___ ___ Python-bug

[issue11957] re.sub confusion between count and flags args

Changes by Eric Snow : -- nosy: -eric.snow ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.

[issue11957] re.sub confusion between count and flags args

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[issue11957] re.sub confusion between count and flags args

Ezio Melotti added the comment: See also #12888 for an error in the stdlib caused by this. -- ___ Python tracker ___ ___ Python-bugs-

[issue11957] re.sub confusion between count and flags args

Éric Araujo added the comment: I’d favor 1) or 2) over 3). Ints are short and very commonly used for flags. -- nosy: +eric.araujo ___ Python tracker ___ ___

[issue11957] re.sub confusion between count and flags args

Changes by Raymond Hettinger : -- assignee: -> rhettinger nosy: +rhettinger ___ Python tracker ___ ___ Python-bugs-list mailing list

[issue11957] re.sub confusion between count and flags args

Terry J. Reedy added the comment: Agreed, if we go that route. -- ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscrib

[issue11957] re.sub confusion between count and flags args

Matthew Barnett added the comment: Something like "" may be more Pythonic. -- ___ Python tracker ___ ___ Python-bugs-list mailing lis

[issue11957] re.sub confusion between count and flags args

Terry J. Reedy added the comment: I like the idea of an internal REflag class with __new__, __or__, and __repr__==__str__. Str(re.A|re.L) might print as "REflag: re.ASCII | re.IGNORE" If it is *not* an int subclass, any attempt to use or mix with an int would raise. I checked and the doc only

[issue11957] re.sub confusion between count and flags args

Ezio Melotti added the comment: Since this has been reported already several times (see e.g. #11947), and it's a fairly common mistake, I think we should do something to avoid it. A few possibilities are: 1) add a warning in the doc; 2) make count and flag keyword-only argument (raising a