Hi Chris, Firstly thanks for your quick reply.
1. Your code example gives a point, but i may not reach my question yet, maybe because i did not make myself understood yet. Here is a more detail example question. I have a classes sets described by UML, which could be refered as Cls_A, Cls_B, CLs_C, Cls_D, Cls_E. There are four relationship between them--dependency, association, aggregation, composition. What i need to do is define all of the classes by python, and,of course, the class definition should describe there relationship correctly. For example, implement composition relationship between Cls_A and Cls_B, which may means a instance of Cls_B is created and destroyed by a Cls_A instance, My code may be like this(not sure since i am not quite familiar with python yet): Cls_a: def __init__(self): self.at1 = 1 Cls_b: def __init__(self): self.com1 = Cls_a() def __del__(self): del self.com1 Is it a right implementation for composition? and i need also do other relationship definition into class, like dependency, association, aggregation... Is there any article or code example on the relationships implementation? Thanks! Biao 2011/11/10 Chris Angelico <ros...@gmail.com> > On Fri, Nov 11, 2011 at 12:15 AM, Jerry Zhang <jerry.scofi...@gmail.com> > wrote: > > For example, in composition model, the container object may be > responsible > > for the handling of embedded objects' lifecycle. What is the python > pattern > > of such implementation? > > Here's an example: > > class Test(object): > def __init__(self): > self.lst=[1,2,3] > self.map={"foo":12,"bar":34} > > This is a container that has a list and a dictionary in it. When an > instance of the container is destroyed, its list and dictionary will > be destroyed too (assuming nobody's made other references to them). > You don't need to code anything explicitly for that. > > Chris Angelico > -- > http://mail.python.org/mailman/listinfo/python-list >
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