declare-non-slot / E0245

Message emitted:

No such name %r in __slots__

Description:

Raised when a type annotation on a class is absent from the list of names in __slots__, and __slots__ does not contain a __dict__ entry.

Problematic code:

class Student:
    __slots__ = ("name",)

    name: str
    surname: str  # [declare-non-slot]

Correct code:

class Student:
    __slots__ = ("name", "surname")

    name: str
    surname: str

Created by the classes checker.