On Apr 1, 9:44 pm, Steven D'Aprano <st...@remove-this- cybersource.com.au> wrote: > On Thu, 01 Apr 2010 19:49:43 -0500, Tim Chase wrote: > > David Robinow wrote: > >> $ python -c "print 1/2 * 1/2" > >> 0 > > >> But that's not what I learned in grade school. > >> (Maybe I should upgrade to 3.1?) > > > That's because you need to promote one of them to a float so you get a > > floating-point result: > > > >>> 1/2 * 1/2 > > 0 > > >>> 1/2 * 1/2.0 > > 0.0 > > > Oh...wait ;-) > > Tim, I'm sure you know the answer to this, but for the benefit of the > Original Poster, the problem is that you need to promote *both* divisions > to floating point. Otherwise one of them will give int 0, which gives 0.0 > when multiplied by 0.5. > > >>> 1.0/2 * 1/2.0 > > 0.25 > > If you want an exact result when multiplying arbitrary fractions, you > need to avoid floats and decimals and use Fractions: > > >>> Fraction(1, 2)**2 > > Fraction(1, 4)
Where do you get that from? > > -- > Steven- Hide quoted text - > > - Show quoted text - -- http://mail.python.org/mailman/listinfo/python-list