What's wrong

Reassigning a value for dataclass member variable from a dataclass member function triggers a stray WPS601 warning.

Here is a code snippet that shows the issue:

from dataclasses import dataclass
from typing import Optional

@dataclass
class DataClass:
    string_value: Optional[str] = None

    def fun(self) -> None:
        self.string_value = self.string_value.strip() if self.string_value else None  # <- WPS601: Found shadowed class attribute: string_value

How it should be

In the code snippet in question there is no shadowing happening, since all instances of string_value are scoped with self.

Flake8 version and plugins

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pip information

pip 20.2.4 from /Users/agatti/Library/Caches/pypoetry/virtualenvs/gls-automator-iJPcva4U-py3.8/lib/python3.8/site-packages/pip (python 3.8)
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OS information

Darwin rotifer.local 19.6.0 Darwin Kernel Version 19.6.0: Tue Jan 12 22:13:05 PST 2021; root:xnu-6153.141.16~1/RELEASE_X86_64 x86_64