invalid-str-returned / E0307

Message emitted:

__str__ does not return str

Description:

Used when a __str__ method returns something which is not a string

Problematic code:

class CustomStr:
    """__str__ returns int"""

    def __str__(self):  # [invalid-str-returned]
        return 1

Correct code:

class CustomStr:
    """__str__ returns <type 'str'>"""

    def __str__(self):
        return "oranges"

Created by the classes checker.