False positive unused-private-member if class member is mutated via cls

[gcolombeau]

Steps to reproduce

Given a file w0238.py:

"""unused-private-member (W0238)"""

class UnusedPrivateMember:
    """unused-private-member (W0238)"""

    __attr_a = None
    __attr_b = 'b'

    @classmethod
    def load_attrs(cls):
        """Load attributes."""
        cls.__attr_a = 'a'

    @property
    def attr_a(self):
        """Get a."""
        return self.__attr_a

    @property
    def attr_b(self):
        """Get b."""
        return self.__attr_b

Current behavior

Result of pylint w0238.py:

************* Module w0238
w0238.py:12:8: W0238: Unused private member `UnusedPrivateMember.__attr_a` (unused-private-member)

Expected behavior

I would expect no unused-private-member warning as cls is inferred as the current class.
However, this example feels error prone under edge cases.

pylint --version output

Result of pylint --version output:

pylint 2.9.3
astroid 2.6.2
Python 3.8.3 (default, Jul  3 2020, 09:39:00) 
[GCC 7.5.0]

[yushao2]

seems similar to #4644 , thanks for reporting this!

[Pierre-Sassoulas]

Do you want to handle this one @yushao2 ?

[alt-yushao2]

Do you want to handle this one @yushao2 ?

Yep, will work on it later