[Python-Dev] PEP239 (Rational Numbers) Reference Implementation and new issues
fperez528 at yahoo.com
Thu Oct 3 23:11:27 CEST 2002
Chad Netzer wrote:
>> Dunno about NaN, but wouldn't rational(Inf) be 1/0?
1/0 -> NaN, b/c you can only define it as a limit and the value of the limit
depends on whether you come into 0 from the right or from the left.
> And what about rational 0/0? Is that 1, or NaN (or Inf :-) )?
NaN. This one isn't defined even as a limit. In expressions that go to 0/0,
you need to figure out which one (num/den) goes faster to 0 to be able to
answer. Long faded memories of calc. classes trickle in ...
ps. I'm not a mathematician, I only play one on TV. But if anyone wants to
whip us with a real analysis text for the gory details, I won't fight back.
More information about the Python-list