On Tue, Nov 6, 2012 at 4:51 PM, Andrew Robinson <andr...@r3dsolutions.com> wrote: > I really don't think doing a shallow copy of lists would break anyone's > program.
Well, it's a change, a semantic change. It's almost certainly going to break _something_. But for the sake of argument, we can suppose that the change could be made. Would it be the right thing to do? Shallow copying by default would result in extremely weird behaviour. All the same confusion would result, only instead of comparing [None]*4 with [[None]]*4, there'd be confusion over the difference between [[None]]*4 and [[[None]]]*4. I don't think it would help anything, and it'd result in a lot more work for no benefit. ChrisA -- http://mail.python.org/mailman/listinfo/python-list