Redundant Final Classvar

What it does

Checks for redundant combinations of the ClassVar and Final type qualifiers.

Why is this bad?

An attribute that is marked Final in a class body is implicitly a class variable. Marking it as ClassVar is therefore redundant.

Note that this diagnostic is not emitted for dataclass fields, where ClassVar[Final[int]] has a distinct meaning from Final[int].

Examples

from typing import ClassVar, Final


class C:
    # redundant
    x: ClassVar[Final[int]] = 1  # error
    # redundant
    y: Final[ClassVar[int]] = 1  # error