It most certainly is a double loop. I can understand how it seems confusing but once you look at what's going on it really isn't all that complicated. Sure the

It most certainly is a double loop. I can understand how it seems confusing but once you look at what's going on it really isn't all that complicated. Sure the syntax is a little less clear (due to the list comprehension, I think Guido is probably cringing right now) but the logic is fairly straightforward.