access-member-before-definition / E0203#

Message emitted:

Access to member %r before its definition line %s

Description:

Used when an instance member is accessed before it's actually assigned.

Correct code:

class Foo:
    def __init__(self, param):
        self.param = param
        if self.param:
            pass

Problematic code:

class Foo:
    def __init__(self, param):
        if self.param:  # [access-member-before-definition]
            pass
        self.param = param

Created by the classes checker.