False positive: PYI015 does not allow assigning typing_extensions.TypeVar

[bryanforbes]

Ruff version: 0.0.261

Given the following file test.pyi:

from typing_extensions import TypeVar

_T = TypeVar('_T', infer_variance=True)

And the following invocation:

ruff --select PYI015 --isolated --no-cache test.pyi

Ruff produces the following error:

test.pyi:3:6: PYI015 [*] Only simple default values allowed for assignments

PEP-695 and PEP-696 are under consideration and add new parameters to TypeVar(). typing_extensions has added a TypeVar class in order to test out these new features before they are accepted. flake8-pyi does not raise Y015 for the above.

[charliermarsh]

It looks like we allow from typing import TypeVar here but not from typing_extensions import TypeVar. I think it's just an oversight. Will double check.

[bryanforbes]

It looks like flake8-pyi checks for both typing and typing_extensions here: https://github.com/PyCQA/flake8-pyi/blob/64863f80c7f91fae23418db048bb41185c2fb5ed/pyi.py#L354