[Python-Dev] Deprecated __cmp__ and total ordering

[Raymond Hettinger]

[Mart Sõmermaa]
> To provide total ordering without __cmp__ one has to implement all of
>  __lt__, __gt__, __le__, __ge__, __eq__ and __ne__. However, in all
> but a few cases it suffices only to provide a "real" implementation for
> e.g. __lt__ and define all the other methods in terms of it as follows:

FWIW, I'm working on a solution for the problem using class decorators.
The idea is that it would scan a class and fill-in missing methods based
on the ones already there.  That way, any one of the four ordering
relations can be provided as a starting point and we won't have to
annoint one like __lt__ as the one true underlying method.

When it's ready, I'll bring it to python-dev for discussion.


Raymond