Basic Terminology

Functions can return instances. For example, find_center takes a Rectangle as an argument and returns a Point that contains the coordinates of the center of the Rectangle:

def find_center(rect):
 p = Point()
 p.x = rect.corner.x + rect.width/2
 p.y = rect.corner.y + rect.height/2
 return p

Here is an example that passes box as an argument and assigns the resulting Point to center:

>>> center = find_center(box)
>>> print_point(center)
(50, 100)