Let: - class Point be a data type which is used to define points in space - class Line be a data type which possesses an aggregate relationship with objects of type Point - class Model be a container class which stores collections of Point and Line objects
Essentially, a Model object stores lists of Point objects and Line objects, and Line objects include references to Point objects which represent the starting and ending point of a line. To reflect this class relationship, I've defined the following classes: <code> class Point: position = [] def __init__(self, x, y, z = 0): self.position = [x, y, z] class Line: points = () def __init__(self, p_i, p_f): self.points = (p_i, p_f) class Model: points = [] lines = [] </code> It would be nice if, whenever a Point object was updated, the Line objects which are associated with it could reflect those updates directly in Line.p_i and Line.p_f. What's the Python way of achieving the same effect? Thanks in advance, Rui Maciel -- http://mail.python.org/mailman/listinfo/python-list