Thanks all, those were some great explanations. It seems I have still still a long way for me to go before I grasp the intricacies of this language.
That 'magic index' variable bugs me a little however. It gives me the same feeling as when I see hard-coded variables. I suppose the generator class has taken care of this with its next() method (although - I should have a look - __next__() probable takes self and index as its arguments). Although I'm very fond of the language (as a non-formally trained hobbyist developer), that "magic" bit is a tad disturbing. Still, thanks for the quick and complete replies! -- http://mail.python.org/mailman/listinfo/python-list