[EMAIL PROTECTED] wrote: > I will read the article you told me to but first, please, have a look > at this snippet: > >>>> m = [2,3,4] >>>> p = ['a','b','c'] >>>> q = [m,p] >>>> q > [[2, 3, 4, 'a', 'b', 'c'], ['a', 'b', 'c']] >>>> del p >>>> q > [[2, 3, 4, 'a', 'b', 'c'], ['a', 'b', 'c']] >>>> > > > How come q is not updated after I deleted p?
q still holds a reference to p. Maybe you are after weak references. Have a look at the documentation for the weakref module in the standard library. Unfortunately you cannot store weak references to lists directly: In [5]: class foo(object): ...: def __init__(self, lst): ...: self.lst = lst In [6]: m = foo([2,3,4]) In [7]: p = foo(['a','b','c']) In [8]: import weakref In [20]: q = [weakref.proxy(m), weakref.proxy(p)] In [23]: q[0].lst, q[1].lst Out[23]: ([2, 3, 4], ['a', 'b', 'c']) In [24]: del p In [27]: q[1].lst gives a reference error -- Jeremy Sanders http://www.jeremysanders.net/ -- http://mail.python.org/mailman/listinfo/python-list
