import typing from typing import Union from unittest import TestCase from typish import get_mro class A: ... class B(A): ... class TestGetMRO(TestCase): def test_get_mro(self): mro_b = get_mro(B) self.assertTupleEqual((B, A, object), mro_b) def test_get_mro_union(self): mro_u = get_mro(Union[int, str]) # Below is to stay compatible with Python 3.5+ super_cls = getattr(typing, '_GenericAlias', getattr(typing, 'GenericMeta', None)) expected = (typing.Union, super_cls, object) self.assertTupleEqual(expected, mro_u) def test_get_mro_object(self): mro_b = get_mro(B()) self.assertTupleEqual((B, A, object), mro_b)