'Platform' object has no attribute 'add_internal'

Question

I have again stumbled across a problem in my Pygame project. In trying to create a group for my platforms, which will aid in coding environmental collision, I am getting the error:

'Platform' object has no attribute 'add_internal'

I have created a group:

platforms=pygame.sprite.Group()
ground=GameClass.Platform(0,500,500,40)
platforms.add(ground)

The ground variable is assigned to the class 'Platform' in the separate file 'GameClass':

class Platform:
    def __init__(self,x,y,w,h):
        self._x=x
        self._y=y
        self._w=w
        self._h=h

        pygame.draw.rect(display,BLACK,[self._x,self._y,self._w,self._h])

The group creation code resides above the game loop, so it is only run once.

Thanks, Link

Answer 1

You can only add instances of pygame.sprite.Sprite subclasses to a pygame.sprite.Group. You also have to call the __init__ method of the superclass: super().__init__() (or super(Platform, self).__init__() in Python 2).

class Platform(pygame.sprite.Sprite):
    def __init__(self,x,y,w,h):
        super().__init__()