Dependency injection by using multiple inheritance

test.py

class Robot(object):
    def move_forward():
        print('Moving forward')

    def move_backward():
        print('Moving backward')


class CleaningRobot(Robot):
    def clean(self, times=10):
        for i in range(times):
            super().move_forward()
            super().move_backward()


# ---------------------------------


class MockBot(Robot):
    def __init__(self):
        self.moves = []

    def move_forward(self):
        self.moves.append('forward')

    def move_backward(self):
        self.moves.append('backward')


class MockedCleaningRobot(CleaningRobot, MockBot):
    pass


def test_clean():
    t = MockedCleaningRobot()
    t.clean(times=2)

    expected = [
        'forward', 'backward',
        'forward', 'backward',
    ]

    assert t.moves == expected

See https://www.youtube.com/watch?v=EiOglTERPEo