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Mon Apr 23 08:05:39 EDT 2001 · http://mail.python.org/pipermail/python-list/2001-April/088632.html

Cedric Adjih wrote:
> 
> M.-A. Lemburg <mal at lemburg.com> wrote:
> > Paul Prescod wrote:
> >>
> >> "M.-A. Lemburg" wrote:
> >> >
> >> >...
> >> >
> >> > from mx.Number import *
> >> > f = Float(3.141)
> >> > r1 = Rational(3.141)
> >> > r2 = Rational(2, 3)
> >> > i = Integer("1231231231231231231231231")
> >>
> >> Wouldn't you more often make a rational from a string instead of a
> >> float? The float loses precision and the rational loses performance so
> >> you've got the worst of both worlds. :)
> >
> > The normal way to create a Rational is to write Rational(2, 3).
> > The next release will also have a string parser for rational
> > numbers (in the format "2/3" and probably "12 2/3" too).
>                                              ^^^^^^
>                                              ^^^^^^
> Just a note:
> This one is cultural and could generate lots of confusion.
> The only way I can parse it is 12*2/3 (I'm French).
> No French book (I know of) uses this notation: 38/3 or 12+2/3
> is used instead. It's as if you wrote the complex number
> 3+4j as "3 4j" (look: "3 4j + 4 5j * 1 7j", hmmm...).

The notation is quite common in financial business and 
mathematics. I agree that it can be confusing, but since the
parser will only accept a single rational in the string, I
believe that at least when using Rational() this behaviour
can be accepted. The situation is different for literals,
of course...

-- 
Marc-Andre Lemburg
______________________________________________________________________
Company & Consulting:                           http://www.egenix.com/
Python Pages:                           http://www.lemburg.com/python/

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ANN: Experimental Number Types (Integer, Rational, Floats)