Comparisons of incompatible types

[Mark Wooding]

Terry Reedy <tjreedy at udel.edu> writes:

> And indeed, code like this that has not been updated does break in
> 3.x. to some people's annoyance. We really really cannot please
> everyone ;-).

The problem is that there are too many useful properties that one might
expect from comparison operators.  For example, it's frequently nice to
have a total ordering on all objects.  For real numbers, it's nice that
the ordering obey the usual ordered-field axioms; but the complex
numbers don't have an ordering compatible with the field operators, and
imposing a default ordering (e.g., degree-lexicographic) is probably
asking for trouble.

I agree that the Python 3 behaviour is an improvement, by the way.

-- [mdw]