To make amends, I tried my own search and came up with this (that you might already have...): http://groups.google.com/group/comp.lang.python/browse_thread/thread/1384f49c35ffba9b/5928092247429e9a%235928092247429e9a?sa=X&oi=groupsr&start=1&num=3 Maybe you'll understand it better than me :-)