[Python-Dev] Re: PEP239 (Rational Numbers) Reference Implementation and new issues (original) (raw)

Oren Tirosh oren-py-d@hishome.net
Wed, 9 Oct 2002 02:02:12 +0200

On Tue, Oct 08, 2002 at 12:09:57PM -0400, Guido van Rossum wrote:

> '3/5' I'd like at least one of those return '0.6' or '0.6r'.

Why should any of them go through a potetially lossy transformation? If you need to approximate a ratio as a finite decimal fraction it should be explicit: str(float(r)).

I think it will also make a good visual cue to always use rational notation for rationals and decimal fractions for floats.

The result of repr() should eval() back to exactly the same object. The result of str() should be the 'pretty' representation because this is the form displayed by print statements and %s formatting. I find '2/3' prettier than '0.666666666667'

pretty-is-in-the-eyes-of-the-beholder-ly yours,

Oren