M.-A. Lemburg <mal <at> egenix.com> writes: > > >>> None > None > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > TypeError: unorderable types: NoneType() > NoneType() > >>> None != None > False > > Two values that compare equal to each other (and are in fact identical), > yet cannot be compared less-than or greater-than.
The error message is clear: "unorderable types". Having some types support an equivalence relation (e.g. "equality") but no intuitive total order relation is hardly a surprise. As someone said, complex numbers are an example of that (not only in Python, but in real life). > This would make sense if you think of None as meaning "anything > and/or nothing", since the left side None could stand for > a different None than the right one, but then you could apply the > same logic to inf: inf is a float instance, and as such supports ordering. I don't see how it invalidates None *not* supporting an order relation, since None isn't a float instance and doesn't pretend to be usable as a number (or as anything supporting ordering, for that matter). _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
