Newbie: question regarding references and class relationships

From	Rui Maciel <rui.maciel@gmail.com>
Newsgroups	comp.lang.python
Subject	Newbie: question regarding references and class relationships
Date	2013-06-10 14:18 +0100
Organization	A noiseless patient Spider
Message-ID	<kp4jf4$5fu$1@dont-email.me> (permalink)

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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

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Thread

Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 14:18 +0100
  Re: Newbie: question regarding references and class relationships Roy Smith <roy@panix.com> - 2013-06-10 09:35 -0400
    Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 14:57 +0100
      Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 15:00 +0100
      Re: Newbie: question regarding references and class relationships Ian Kelly <ian.g.kelly@gmail.com> - 2013-06-10 13:56 -0600
        Re: Newbie: question regarding references and class relationships Rick Johnson <rantingrickjohnson@gmail.com> - 2013-06-11 17:02 -0700
  Re: Newbie: question regarding references and class relationships Peter Otten <__peter__@web.de> - 2013-06-10 15:49 +0200
    Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 14:59 +0100
      Re: Newbie: question regarding references and class relationships Peter Otten <__peter__@web.de> - 2013-06-10 16:28 +0200
        Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 15:38 +0100
          Re: Newbie: question regarding references and class relationships Peter Otten <__peter__@web.de> - 2013-06-10 17:05 +0200
            Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 16:20 +0100
              Re: Newbie: question regarding references and class relationships Peter Otten <__peter__@web.de> - 2013-06-10 17:55 +0200
                Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 17:09 +0100
                Re: Newbie: question regarding references and class relationships Peter Otten <__peter__@web.de> - 2013-06-10 19:07 +0200
                Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 18:42 +0100
                Re: Newbie: question regarding references and class relationships Dave Angel <davea@davea.name> - 2013-06-10 15:36 -0400
                Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 21:31 +0100
                Re: Newbie: question regarding references and class relationships Terry Jan Reedy <tjreedy@udel.edu> - 2013-06-10 15:51 -0400
                Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 21:13 +0100
                Re: Newbie: question regarding references and class relationships Terry Jan Reedy <tjreedy@udel.edu> - 2013-06-10 18:07 -0400
                Re: Newbie: question regarding references and class relationships Grant Edwards <invalid@invalid.invalid> - 2013-06-10 22:39 +0000
                Re: Newbie: question regarding references and class relationships Chris Angelico <rosuav@gmail.com> - 2013-06-11 08:54 +1000
                Re: Newbie: question regarding references and class relationships Tim Chase <python.list@tim.thechases.com> - 2013-06-10 18:24 -0500
                Re: Newbie: question regarding references and class relationships Dave Angel <davea@davea.name> - 2013-06-10 19:26 -0400
                Re: Newbie: question regarding references and class relationships Jason Swails <jason.swails@gmail.com> - 2013-06-10 23:49 -0400
  Re: Newbie: question regarding references and class relationships Terry Jan Reedy <tjreedy@udel.edu> - 2013-06-10 15:54 -0400
    Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-10 21:09 +0100
  Re: Newbie: question regarding references and class relationships Rick Johnson <rantingrickjohnson@gmail.com> - 2013-06-11 16:50 -0700
    Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-13 13:06 +0100
      Re: Newbie: question regarding references and class relationships Chris Angelico <rosuav@gmail.com> - 2013-06-14 00:07 +1000
        Re: Newbie: question regarding references and class relationships Rui Maciel <rui.maciel@gmail.com> - 2013-06-13 19:23 +0100

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