[pygame] Not sure what to call this.

["Lamonte Harris" <pyth0nc0d3r@xxxxxxxxx>]

Basically lets give a real live example.  When your standing up and you move your arm at an diagonal the socket of the bone doesn't move but your arm does, lets put this back to pygame.  How would Say if K have a simple sprite that has 2 parts body,1 arm.  How would say if that sprite is in the middle of the screen don't move but when I move the mouse the arm points in the direction of where the mouse is located, but doesn't exactly move to that position, how would that exactly work?