[Python-Dev] Decimal <-> float comparisons in py3k.

[Raymond Hettinger]

On Mar 16, 2010, at 9:41 AM, Guido van Rossum wrote:

> I'd say if you're not going to forward-port this to Python 3, it
> shouldn't go into Python 2 -- in that case it would make more sense to
> me to back-port the exception-raising behavior.

Python 3 doesn't need it because it is possible to not give a result
at all.  Python 2 does need it because we have to give *some*
result.

> 
> Also supporting comparisons but not other mixed operations is going to
> be confusing. If you are sticking to that behavior I think mixed
> comparisons should also be ruled out.

The difference is that mixed comparisons currently do give a result,
but one that is non-sensical.  The proposal is a make in give a
meaningful result, not as an extra feature, but in an effort to not
be wrong.

Since 2.x has to give a result, we should make it useful.
Since 3.x does not make the comparison, it is okay to punt.


Raymond