For the sake of completeness (I didn't copy this message to the list): > I have a problem with initialization. > >>> a, b = [[]]*2 > >>> a.append(1) > >>> b > [1] > > Why is this? Why does not this behave like the below:
You create a single list (inside your brachets) and duplicate a reference to it. a and b are two references to the same list; this is just a problem for mutable objects, but I think it's safe to say that it bites everyone at some point. > >>> [[], []] == [[]]*2 > True Obviously, this is not a test for referential identity. Hope this helps to clear the matter up! Ole 2005/8/10, Jiri Barton <[EMAIL PROTECTED]>: > Yes, now it is clear! > > As always, I should have RTFM, the operator* is not just a syntactic sugar > and thus does not make copies. You know, my actual scenario was with four > variables at the time: > > a, b, c, d = [], [], [], [] > > so I was even more tempted to use the previous and wrong approach:-) > > Thank you for your explanation. No more errors in my code from now on (oh > well,...) > > jbar > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
