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Jeff, I think the problem is that the list returned from foo is a RHS value (term?). Many other languages generate compile time, or run time errors when you attempt to modify a value like this. Python allows you to operate on RHS values and to good benefit. It gives you the ability to write "/n".join([1, 2, 3,4]), etc. In your case the list is probably being created as you expected, it is just transient and you never see it - remember list.extent() modifies a list in place, and doesn't return the list. Because extend doesn't return a list, you need something else. Try using '+': L = map(lambda x: foo(x) + foo(x+2), L) Hope this helps a little. Kevin On 2004年10月17日 19:52:27 -0400, Jeff Abrahamson <jeff@purple.com> wrote: > In the below, I want L=[3,4,5,6] at the end. Clearly that's not > what's happening. > > The problem is that I want to use a map with a lambda form, so I can't > make assignments. > > >>> def foo(x): > ... return [x,x+1] > ... > >>> foo(3) > [3, 4] > >>> foo(3).extend(foo(5)) > >>> L=foo(3).extend(foo(5)) > >>> L > >>> > > I want to write something like this: > > L = map(lambda x: foo(x).extend(foo(x+2)), L) > > Any thoughts? > > I might have to break down and name this function... > > -- > Jeff > > Jeff Abrahamson <http://www.purple.com/jeff/> +1 215/837-2287 > GPG fingerprint: 1A1A BA95 D082 A558 A276 63C6 16BF 8C4C 0D1D AE4B > > A cool book of games, highly worth checking out: > http://www.amazon.com/exec/obidos/ASIN/1931686963/purple-20 > > > ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug