Python: Trying to use polymorphism with pygame -
i'm trying use polymorphism in pygame project keep getting errors.
i have moveable class , objects class inherits moveable , attributeerror: 'nonetype' object has no attribute 'ypos' in game loop.
i plan on having more moveable objects in project people, houses, road signs... if can working.
class moveable: __name = "" __xpos = 0 __ypos = 0 __hight = 0 __width = 0 __speed = 0 __image = 0 def __init__(self, xpos, ypos, hight, width, speed, image): self.__xpos = xpos self.__ypos = ypos self.__hight = hight self.__width = width self.__image = image def set_xpos(self, xpos): self.__xpos = xpos def get_xpos(self): return self.__xpos # ... , other getters , setters... class objects(moveable): def car(xpos, ypos, width, hight, speed, image): pygame.surface.blit(gamedisplay, image, [xpos, ypos, hight, width]) def game_loop(): game_exit = false #sets game loop false while not game_exit: # runs game loop until game exit = true car = objects.car(random.randrange(250, 550), -400, 60, 70, 4, pygame.image.load('car.png')) gamedisplay.blit(backgroundimg, (0, 0)) #displays background car.ypos += car.speed # error here ********** r
you need return pygame if intent.
def car(xpos, ypos, width, hight, speed, image): return pygame.surface.blit(gamedisplay, image, [xpos, ypos, hight, width]) as stands, car has no return statement, assigning variable method return none, hence error trying access attribute on nonetype