import Lumpy lumpy = Lumpy.Lumpy() lumpy.make_reference() class Rectangle: pass class Point: pass def find_center(box): corner = box.corner p = Point() p.x = box.corner.x + box.width/2 p.y = box.corner.y + box.height/2 lumpy.object_diagram() return p box = Rectangle() box.width = 100 box.height = 200 box.corner = Point() box.corner.x = 10 box.corner.y = 20 center = find_center(box)