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0.981 @classmethod and @property can no longer be chained #13746
Description
Class properties were introduced in Python 3.9, and used to be unanalysed in 0.971:
# mypy 0.971
class A:
@property
@classmethod
def bad_class_property(cls) -> int: # No mypy error
return 8
@classmethod
@property
def good_class_property(cls) -> int: # No mypy error
return 8>>> A.bad_class_property
<property at 0x...>
>>> A.good_class_property
8Now, we have
# mypy 0.981
class A:
@classmethod # Only instance methods can be decorated with @property [misc]
@property
def good_class_property(cls) -> int:
return 8
Activity
erictraut commentedon Sep 27, 2022
I don't know if this was related to the change in mypy 0.981, but chaining of property and classmethod has been deprecated in Python 3.11. More details can be found in the Python 3.11 release notes, but I'll quote the relevant part here:
hauntsaninja commentedon Sep 27, 2022
Yeah, this is from #13409. I don't think mypy should support property + classmethod, given that it's deprecated. But that can be discussed at #11619
Fix errors reported by new version of mypy
Fix errors reported by new version of mypy
Fix errors reported by new version of mypy