[Terry Reedy]
For user-defined types/classes, I presume that this would still mean deferring to the appropriate magic method (__cmp__ or __ge__?) to define 'meaningful'.
Yes. And I'm still hoping to remove __cmp__; there should be only one way to overload comparisons.
I'd like to to this in Python 3.0, but that probably means we'd have to start deprecating default comparisons except (in)equality in Python 2.4.
+1, I think.
Based on reading cl.py, the validity of nonsense comparisons is one of the more surprising 'features' of Python for beginners -- who reasonably expect a TypeError or ValueError. Once they get past that, they are then surprised by the unstability across versions. Given that universal sorting of hetero-lists is now broken, I think it would be better to do away with it cleanly. It is seldom needed and would still be available with a user-defined sorting function (which requires some thought as to what is really wanted).
Exactly.
A Python version of the present algorithm could be included (in Tools/xx perhaps) for anyone who actually needs it.
I doubt there will be many takers. Let people make up their own version, so they know its behavior. --Guido van Rossum (home page: http://www.python.org/~guido/)