invalid-slots-object / E0236#

Message emitted:

Invalid object %r in __slots__, must contain only non empty strings

Description:

Used when an invalid (non-string) object occurs in __slots__.

Problematic code:

class Person:
    __slots__ = ('name', 3)  # [invalid-slots-object]

Correct code:

class Person:
    __slots__ = ('name', 'surname')

Related links:

Created by the classes checker.