New submission from Miro Hrončok <m...@hroncok.cz>:
I believe I found a regression in Enum in Python 3.10.0a5.
This is Python 3.9:
>>> import enum
>>> class C(enum.Enum):
... A = 0
... B = 1
...
>>> C.A
<C.A: 0>
>>> C.B
<C.B: 1>
>>> C(0).A
<C.A: 0>
>>> C(0).B
<C.B: 1>
>>>
The Enum instances can access class-attributes via dot, like normal instances
do.
While in Python 3.10.0a5:
>>> import enum
>>> class C(enum.Enum):
... A = 0
... B = 1
...
>>> C.A
<C.A: 0>
>>> C.B
<C.B: 1>
>>> C(0).A
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python3.10/enum.py", line 146, in __get__
raise AttributeError(
AttributeError: C: no attribute 'A'
>>> C(0).B
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python3.10/enum.py", line 146, in __get__
raise AttributeError(
AttributeError: C: no attribute 'B'
In real word situations, it breaks meson:
https://github.com/mesonbuild/meson/blob/398df5629863e913fa603cbf02c525a9f501f8a8/mesonbuild/backend/backends.py#L52-L78
The __str__ method does:
if self is self.EXITCODE: ...
And it fails with:
AttributeError: TestProtocol: no attribute 'EXITCODE'
This worked with 3.10.0a4.
If this is a deliberate backwards incompatible change of behavior, I don't
think it is documented in the changelog or what's new in Python 3.10, nor that
it was deprecated in Python 3.9 and 3.8.
----------
components: Library (Lib)
messages: 386626
nosy: hroncok
priority: normal
severity: normal
status: open
title: Enum regression: AttributeError when accessing class variables on
instances
type: behavior
versions: Python 3.10
_______________________________________
Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue43162>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
