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Python 3.11.0b4 str(enum) giving integer value and not name #94763
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[-]Python 3.11 str(enum) giving integer value and not name[/-][+]Python 3.11.0b4 str(enum) giving integer value and not name[/+]on Jul 11, 2022 I believe that this is a deliberate behaviour change from previous versions. The Steering Council specifically approved this change; see the penultimate paragraph here regarding aligning
str()andformat()forIntEnum: https://mail.python.org/archives/list/python-dev@python.org/message/RN3WCRZSTQR55DOHJTZ2KIO6CZPJPCU7/Reacted by Jordan Borean and Daniël van Noord#22392 does seem somewhat related but it does mention only string enums should use the values and other types use the member name. If this is a change made on purpose that's fine, I just want to know for sure and whether to update my tests.
Edit: Sorry you posted just as I was commenting.
Reacted by Alex WaygoodMy apologies for the confusion, I need to get the Whats New updated with the Enum changes/additions.
No worries, so just to confirm this is expected for pretty much any enum types and not just a string enum as mentioned in the linked issue?
This is (now) the expected behavior for any mixed Enum/Flag defined in the enum module. The expectation is that existing code being replaced with
IntEnum,StrEnum, orIntFlagshould have itsstr()continue to be the same as it was; if you mix your own (i.e.MyIntEnum(int, Enum)) then you get the original behavior of bothrepr()andstr()being overridden. In either case,format()will be the same asstr().@ethanfurman So what is the idiomatic way to get the member name rather than the value? In 3.10 I have:
>>> fs.FileType.__mro__ (<enum 'FileType'>, <enum 'IntEnum'>, int, <enum 'Enum'>, object) >>> str(fs.FileType.Directory) 'FileType.Directory' >>> repr(fs.FileType.Directory) '<FileType.Directory: 3>'
How do I get
'FileType.Directory'with 3.11?I know it was intentional, but just as a data point, the breaking changes to
formatforMyEnum(str, Enum)did cause some downstream breakage, such as:How do I get
'FileType.Directory'with 3.11?@pitrou Either change the
__str__for theFileTypeenum, or make a new base enum to inherit from:class OldIntEnum(int, Enum): """ use the `classname.membername` str() """ pass
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on Dec 17, 2022 @ethanfurman I know this is probably water under the bridge now, but I wonder why breaking changes like this are not called out more distinctly in the What's New (e.g. by including the word "breaking")?!
We just had code using plain
IntEnum/IntFlagchange behaviour on Python 3.11, and now have a hard time working around that breaking change (probably by inheriting from (int, Enum) to support all current Python versions and our user's use case.
Hitting surprises like this is unpleasant, and I have to admit they somewhat undermine my trust in the versioning scheme.Could breaking changes at least be marked/called out with "breaking" or somesuch? Then it's easier to grep the What's new when, against expectations, a minor version upgrades changes public behaviour. :-(
Reacted by jamiecha, Fabian Henze and Nico Neumann- added a commit that references this issue
on Sep 30, 2025 - added a commit that references this issue
on Oct 27, 2025
Bug report
The
str()method on Python 3.11.0b4 is outputting the raw integer value not the class name and label that older Python versions do.On Python 3.10 (and older Python 3 versions) this assertion is true. On python 3.11.0b4 the str value is just
1.The
repr()is the same as on older versions, just seems likestr()is affected.Your environment