def draw_arrows(self):
        """Draw arrows on the body surface."""
        ### calculate the offset between the body rect
        ### topleft coordinates and the origin of the screen,
        ### which happens to be equal to the inverse of the
        ### topleft coordinates
        offset = tuple(-n for n in self.body.rect.topleft)

        ### iterate over arrows, blitting them on the
        ### body surface using the offset to move their
        ### rects non-destructively, so they are drawn
        ### in the appropriate position in the body surface

        for arrow in self.arrows:
            self.body.image.blit(arrow.image, arrow.rect.move(offset))
Draw arrows on the body surface.
nodezator/menu/submenu/scroll.py