Bug report
Bug description:
The inspect.ismethoddescriptor() function reports descriptor objects which implement __delete__() but not __set__() as method descriptors, even though they are, in fact, data descriptors:
Actual behavior example:
>>> import inspect
>>> class Descriptor:
... def __get__(self, *_): pass
... def __delete__(self, *_): pass # Note: `__set__()` *not* defined.
...
>>> inspect.ismethoddescriptor(Descriptor()) # Wrong result:
True
Expected result:
>>> inspect.ismethoddescriptor(Descriptor()) # Correct result:
False
See also: https://discuss.python.org/t/inspect-ismethoddescriptor-checks-for-the-lack-of-set-but-ignores-delete-should-it-be-fixed/55039
There is an additional question: to which Python versions should the fix be applied?
IMHO, the fix can be safely applied to the branches 3.14 (main) and 3.13 (still in the beta phase). Backporting it to the earlier versions might be considered too disruptive. Obviously, the decision will need to be made by a core developer, not me.
CPython versions tested on:
3.8, 3.9, 3.10, 3.11, 3.12, 3.13, CPython main branch
Linked PRs
Bug report
Bug description:
The
inspect.ismethoddescriptor()function reports descriptor objects which implement__delete__()but not__set__()as method descriptors, even though they are, in fact, data descriptors:Actual behavior example:
Expected result:
See also: https://discuss.python.org/t/inspect-ismethoddescriptor-checks-for-the-lack-of-set-but-ignores-delete-should-it-be-fixed/55039
There is an additional question: to which Python versions should the fix be applied?
IMHO, the fix can be safely applied to the branches 3.14 (main) and 3.13 (still in the beta phase). Backporting it to the earlier versions might be considered too disruptive. Obviously, the decision will need to be made by a core developer, not me.
CPython versions tested on:
3.8, 3.9, 3.10, 3.11, 3.12, 3.13, CPython main branch
Linked PRs