On Mon, 29 Jul 2013 17:20:27 +0100, Chris Angelico wrote: >>>> Fraction(0.3) > Fraction(5404319552844595, 18014398509481984) >>>> Fraction(0.33) > Fraction(5944751508129055, 18014398509481984) [...] >>>> Fraction(0.33333333333333333) > Fraction(6004799503160661, 18014398509481984) > > Rounding off like that is a job for a cool library function (one of > which was mentioned on this list a little while ago, I believe), but not > IMO for the Fraction constructor.
Or: py> Fraction(1/3).limit_denominator(100) Fraction(1, 3) I think it would be useful for Fraction.from_float() to accept an optional second argument, the maximum denominator: Fraction.from_float(x, den=None) => nearest fraction to float 1/3, with denominator no greater than den -- Steven -- http://mail.python.org/mailman/listinfo/python-list
