M.-A. Lemburg wrote: > IMO, it was a mistake to have None return a TypeError in > comparisons, since it makes many typical data operations > fail, e.g. > > Python2: >>>> l = [1,2,None,4,5,None,6] >>>> l.sort() >>>> l > [None, None, 1, 2, 4, 5, 6] > > Python3: >>>> l = [1,2,None,4,5,None,6] >>>> l.sort() > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > TypeError: unorderable types: NoneType() < int() While it is trivial to fix
>>> sorted([1,2,None,4,5,None,6], ... key=lambda x: (x is None, x)) [1, 2, 4, 5, 6, None, None] maybe the key should be given a name like functools.none_first/none_last in order to offer a standard approach? On the other hand I'm not sure I like none_last(x) < none_last(y) _______________________________________________ Python-Dev mailing list [email protected] https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com