Generalized game object probably the actual thing that needs to be built to do this sort of thing.

basegameobject.py

class BaseGameObject(DirtySprite):
    group = None
    image_path = None
    image = None

    def __init__(self, scene, position=(0, 0)):
        cls = self.__class__
        if cls.group is None:
            cls.group = cls.__name__
        super().__init__(scene.groups[cls.group], scene.groups["render"])
        self.scene = scene
        if cls.image is None and cls.image_path:
            cls.image = cls.transform(image.load(path.join(ROOT_DIR, cls.image_path)))
        self.rect = None
        if cls.image:
            self.rect = cls.image.get_rect()
        if self.rect is not None:
            self.rect.center = position
        self.last_position = position

    def update(self, time_delta):
        self.simulate(time_delta)
        if self.rect.center != self.last_position:
            self.dirty = True
            self.last_position = self.rect.center

    def simulate(self, time_delta):
        pass

    @staticmethod
    def transform(image):
        return image