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Convert a warning about flags not at the start of the regular expression into error #91222

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serhiy-storchaka opened this issue Mar 19, 2022 · 8 comments
Closed

Convert a warning about flags not at the start of the regular expression into error #91222

serhiy-storchaka opened this issue Mar 19, 2022 · 8 comments
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3.11 only security fixes stdlib Python modules in the Lib dir topic-regex type-bug An unexpected behavior, bug, or error

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@serhiy-storchaka
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BPO 47066
Nosy @ezio-melotti, @serhiy-storchaka
PRs
  • bpo-47066: Convert a warning about flags not at the start of the regu… #31994
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    Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.

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    GitHub fields:

    assignee = None
closed_at = <Date 2022-03-19.14:12:52.270>
created_at = <Date 2022-03-19.12:09:48.176>
labels = ['expert-regex', 'type-bug', 'library', '3.11']
title = 'Convert a warning about flags not at the start of the regular expression into error'
updated_at = <Date 2022-03-19.14:12:52.269>
user = 'https://github.com/serhiy-storchaka'

    bugs.python.org fields:

    activity = <Date 2022-03-19.14:12:52.269>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = True
closed_date = <Date 2022-03-19.14:12:52.270>
closer = 'serhiy.storchaka'
components = ['Library (Lib)', 'Regular Expressions']
creation = <Date 2022-03-19.12:09:48.176>
creator = 'serhiy.storchaka'
dependencies = []
files = []
hgrepos = []
issue_num = 47066
keywords = ['patch']
message_count = 2.0
messages = ['415544', '415552']
nosy_count = 3.0
nosy_names = ['ezio.melotti', 'mrabarnett', 'serhiy.storchaka']
pr_nums = ['31994']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue47066'
versions = ['Python 3.11']
    @serhiy-storchaka
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    This warning was introduced in 3.6. The reason is that in most other regular expression implementations global inline flags in the middle of the expression have different semantic: they affect only the part of the expression after the flag. But in Python they affect the whole expression. It caused confusion and was a source of bugs.

    After 5 releases it is a time to convert this warning into error. In future we can allow global inline flags in the middle of the expression with different semantic. It is safer if one or more intermediate versions will raise an error.

    @serhiy-storchaka serhiy-storchaka added 3.11 only security fixes stdlib Python modules in the Lib dir topic-regex type-bug An unexpected behavior, bug, or error labels Mar 19, 2022
    @serhiy-storchaka
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    New changeset 92a6abf by Serhiy Storchaka in branch 'main':
    bpo-47066: Convert a warning about flags not at the start of the regular expression into error (GH-31994)
    92a6abf

    @ezio-melotti ezio-melotti transferred this issue from another repository Apr 10, 2022
    jwilk added a commit to jwilk/pydiatra that referenced this issue May 11, 2022
    @jwilk
    pydiatra.check_re: fix regexp-misplaced-inline-flags for Python ≥ 3.11.
    433dd1a 
    Misplaced inline flags are no longer allowed in Python 3.11:
python/cpython#91222
    @RaMdsC RaMdsC mentioned this issue Nov 16, 2022
    Closed
    @lorypiro24 lorypiro24 mentioned this issue Nov 19, 2022
    Open
    @singingwolfboy singingwolfboy mentioned this issue Nov 23, 2022
    Merged
    @mitya57 mitya57 mentioned this issue Dec 17, 2022
    Merged
    @iamjackg iamjackg mentioned this issue Jan 31, 2023
    Closed
    robertzee pushed a commit to robertzee/jinja2-htmlcompress that referenced this issue Feb 3, 2023
    Fix Error in Python 3.11: Global Inline Flag in Regular Expression.
    4a52e44 
    Refer to: python/cpython#91222
    @robertzee robertzee mentioned this issue Feb 3, 2023
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    @jrmuizel
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    For the record here's some brokenness this caused:
    https://bz.mercurial-scm.org/show_bug.cgi?id=6759
    https://bugzilla.mozilla.org/show_bug.cgi?id=1799982

    @arhadthedev
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    @jrmuizel Could you report this in a new issue mentioning this issue, please? I suspect almost nobody reads already closed entries.

    @jrmuizel
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    Is it worth filing a new issue even though both of those uses have already been fixed upstream?

    @arhadthedev
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    My bad. I've thought you linked to some extra issues similar to this but found by third-party projects that use Python.

    @toastwaffle toastwaffle mentioned this issue May 16, 2023
    Merged
    @lachesis

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    @frbor frbor mentioned this issue May 25, 2023
    Merged
    @gilch gilch mentioned this issue May 25, 2023
    Closed
    @slurpyb slurpyb mentioned this issue Jul 16, 2023
    Closed
    slurpyb added a commit to slurpyb/simple-ddl-parser that referenced this issue Jul 16, 2023
    @slurpyb
    Move inline flag to start of regex
    c5b6b06 
    3.11 requires global flags at the start (bpo-47066). See python/cpython#91222
    @slurpyb slurpyb mentioned this issue Jul 16, 2023
    Merged
    xnuinside pushed a commit to xnuinside/simple-ddl-parser that referenced this issue Aug 20, 2023
    @slurpyb
    Move inline flag to start of regex (#200)
    1c292ef 
    3.11 requires global flags at the start (bpo-47066). See python/cpython#91222
    @davelopez davelopez mentioned this issue Sep 13, 2023
    Merged
    5 tasks
    @yilei
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    yilei commented Sep 26, 2023 •
    edited

    #TIL if the intent was to only apply the flag to a subset of the regex, e.g.:

    r"name-((?i)CASE-INSENSITIVE)"

    You can use the following:

    r"name-(?i:CASE-INSENSITIVE)"

    See the (?aiLmsux-imsx:...) section under https://docs.python.org/3/library/re.html#regular-expression-syntax

    It would be great if this was mentioned on https://docs.python.org/3/whatsnew/3.11.html#porting-to-python-3-11 as I have "migrated" dozens of files running into this issue where the original intent was to only apply the flag to a subset (especially when you concatenate regexes together), but I only learned about this today. (I hope this comment can at least help some when they click the bpo-47066 link there and get redirected here.

    Also, there is no mention of the word "global" on https://docs.python.org/3/library/re.html, as it seems ideal if that could mention "global" v.s. "local" inline flags.

    @itsthejb itsthejb mentioned this issue Oct 1, 2023
    Closed
    @thebaptiste thebaptiste mentioned this issue Dec 17, 2023
    Closed
    @Simon-1-1 Simon-1-1 mentioned this issue Dec 28, 2023
    Merged
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