def __sub__(self, arg):
        """Return a new Vec2 containing the difference between our x and y and
        arg.
        If argument is a float or vec, subtract it from our x and y.
        Otherwise, treat is as a Vec2 and subtract arg.x and arg.y from our own
        x and y.
        """

        if type(arg) is float or type(arg) is int:
            return Vec2(self.x - arg, self.y - arg)
        else:
            return Vec2(self.x - arg.x, self.y - arg.y)
def __sub__ ( self , arg ) : if type ( arg ) is float or type ( arg ) is int : return Vec2 ( self . x - arg , self . y - arg ) else : return Vec2 ( self . x - arg . x , self . y - arg . y )
Return a new Vec2 containing the difference between our x and y and
        arg.
        If argument is a float or vec, subtract it from our x and y.
        Otherwise, treat is as a Vec2 and subtract arg.x and arg.y from our own
        x and y.