Bug report
Bug description:
Below is a simplification of some classes that create the problem:
import typing
K = typing.TypeVar("K")
V = typing.TypeVar("V")
class BaseMap(typing.Mapping[K, V]): ...
class MutableMap(BaseMap[K, V], typing.MutableMapping[K, V]): ...
class MyMap(typing.Dict[K, V], MutableMap[K, V]): ...Just entering these definitions in the REPL causes the error.
The stack trace (with info about variable b):
b=__main__.MutableMap[~V]
type(b)=<class 'types.GenericAlias'>
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
class MyMap(typing.Dict[K, V], MutableMap[V]): ...
File "/home/russell/.pyenv/versions/3.13-dev/lib/python3.13/typing.py", line 1391, in __mro_entries__
return super().__mro_entries__(bases)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^
File "/home/russell/.pyenv/versions/3.13-dev/lib/python3.13/typing.py", line 1143, in __mro_entries__
if isinstance(b, _BaseGenericAlias) or issubclass(b, Generic):
~~~~~~~~~~^^^^^^^^^^^^
TypeError: issubclass() arg 1 must be a class
This works "fine" before Python 3.13. If I swap the order of typing.Dict[K, V], MutableMap[V], the error no longer presents on 3.13.
I don't understand enough of intersection of these topics to know if this is now an expected error or something is considered wrong. This does seem related to #103369.
CPython versions tested on:
3.8, 3.9, 3.10, 3.11, 3.12, 3.13, CPython main branch
Operating systems tested on:
Linux
Linked PRs
Bug report
Bug description:
Below is a simplification of some classes that create the problem:
Just entering these definitions in the REPL causes the error.
The stack trace (with info about variable
b):This works "fine" before Python 3.13. If I swap the order of
typing.Dict[K, V], MutableMap[V], the error no longer presents on 3.13.I don't understand enough of intersection of these topics to know if this is now an expected error or something is considered wrong. This does seem related to #103369.
CPython versions tested on:
3.8, 3.9, 3.10, 3.11, 3.12, 3.13, CPython main branch
Operating systems tested on:
Linux
Linked PRs
GenericAliastypes #112926