__lt__ instead of __cmp__

Question

Python 2.x has two ways to overload comparison operators, __cmp__ or the \"rich comparison operators\" such as __lt__. The rich comparison overloads are said to be

Answer 1

(Edited 6/17/17 to take comments into account.)

I tried out the comparable mixin answer above. I ran into trouble with "None". Here is a modified version that handles equality comparisons with "None". (I saw no reason to bother with inequality comparisons with None as lacking semantics):

class ComparableMixin(object):

    def __eq__(self, other):
        if not isinstance(other, type(self)): 
            return NotImplemented
        else:
            return not self