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AttributeError when copying flags in the re module. #93820
Description
Activity
Thanks for reporting! Confirmed that
copy.copy(re.A | re.I)fails on 3.11 but works on 3.10. Marking as a release blocker since this is a regression.cc @ethanfurman for enums
Reacted by Phillip SchanelyAlso repros with
enum.IntFlagdirectly:$ ./python.exe Python 3.11.0b3+ (heads/3.11:7aa4038a6e, Jun 14 2022, 09:35:10) [Clang 13.0.0 (clang-1300.0.29.3)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import copy, enum >>> class F(enum.IntFlag): ... a = 2 ... b = 4 ... >>> copy.copy(F.a | F.b) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Users/jelle/py/cpython/Lib/copy.py", line 102, in copy return _reconstruct(x, None, *rv) ^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/jelle/py/cpython/Lib/copy.py", line 265, in _reconstruct y = func(*args) ^^^^^^^^^^^ File "/Users/jelle/py/cpython/Lib/enum.py", line 862, in __getattr__ raise AttributeError(name) from None ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ AttributeError: a|bAlso occurs on 3.12
In 3.11 the
__reduce__and__reduce_ex__methods returns different values:# 3.10 >>> import re >>> flags = re.I | re.A >>> flags.__reduce__() (<function _reconstructor at 0x7f58bb775ea0>, (<enum 'RegexFlag'>, <class 'int'>, 258), {'_name_': None, '_value_': 258}) >>> flags.__reduce_ex__(1) (<enum 'RegexFlag'>, (258,)) >>> flags._name_ is None True >>> flags.name is None True
# 3.11 >>> import re >>> flags = re.I | re.A >>> flags.__reduce__() (<function _reconstructor at 0x7fd0b8d4f920>, (<flag 'RegexFlag'>, <class 'int'>, 258), {'_value_': 258, '_name_': 'ASCII|IGNORECASE'}) >>> flags.__reduce_ex__(1) (<built-in function getattr>, (<flag 'RegexFlag'>, 'ASCII|IGNORECASE')) >>> flags._name_ 'ASCII|IGNORECASE' >>> flags.name 'ASCII|IGNORECASE'
Oh, it looks like we came across it at the same time 😂
Reacted by Christian HeimesPR #93876 is a potential fix. Waiting for @ethanfurman to confirm.
Ideally,
re.I | re.Ashould be reconstructed asoperator.or_(re.ASCII, re.IGNORECASE).It gets a bit tricky when the flags have a residual member, e.g.
re.A | re.I | 0x10000. IntFlag supports additional values that are not covered by an enum member.- added 4 commits that reference this issue
on Jun 26, 2022
Bug report
In CPython 3.11, I've noticed that an attempt to copy (combined) regular expression flags fails with an attribute error; like so:
Your environment
Background
This behavior was detected from a CrossHair test failure here, in which we realize possibly symbolic arguments prior to regex compilation. (it's an esoteric use case, and I expect not very high priority)