[PyGame] Sprites just randomly appear and dissapear in my pygame.sprite.GoupeSingle

[deanhystad]

update_Hauptmenu() calls pytame.display.update(), but it does nothing to "erase" sprites that have been removed. There is no erasing in Pygame, so if you want to erase something from the screen you have to paint over it, then draw all your sprites, and finally call display update() or flip().