On Thu, Jan 1, 2009 at 1:13 PM, <davida...@gmail.com> wrote: > Consider these two lists comprehensions: > > L1=[[1 for j in range(3)] for i in range(3)] > L2=[[1]*3]*3 > [snip] > > It seems a misbehaviour in Python, or there is something I do not > understand in the syntax ????
It's not a Python bug. Does this help illuminate the difference? >>> L1 = [object() for j in range(3)] >>> L2 = [object()] * 3 >>> [id(o) for o in L1] [164968, 164976, 164984] >>> L1[0] is L1[1] False >>> [id(o) for o in L2] [164992, 164992, 164992] >>> L2[0] is L2[1] True -Miles -- http://mail.python.org/mailman/listinfo/python-list
