josh logan <[EMAIL PROTECTED]> writes: > sorted(P) # throws TypeError: unorderable types Player() < Player() > > The sorted function works when I define __lt__. > I must be misreading the documentation, because I read for the > documentation __cmp__ that it is called if none of the other rich > comparison functions are defined. > Is this a bug in Python 3.0rc1, or am I missing something?
What documentation are you referring to, exactly? The whole __cmp__ thing was supposed to be removed from Python 3, so mention of it sounds like a documentation bug. > Secondly, say that we suddenly need another sorting order, where we > want to sort by decreasing score and then by DECREASING last name > (instead of increasing last name, defined above). Now that the > comparison function argument is taken away from the sorted builtin, > how do we accomplish this with the "key" parameter? By calling sort twice on the sequence: lst.sort(key=lambda x: x.score) lst.sort(key=lambda x: x.last_name, reverse=True) As much as I like the key argument, I believe it was a mistake to remove cmp, simply because it was the more general mechanism. Emulating cmp with key is possible, but it requires creating a bunch of objects for each sort. (I'm aware that list.sort caches the calculated keys, but it still has to create as many of them as there are list items.) -- http://mail.python.org/mailman/listinfo/python-list
