On Mon, Jul 29, 2013 at 9:43 AM, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: > Comparing floats to Fractions gives unexpected results: > > # Python 3.3 > py> from fractions import Fraction > py> 1/3 == Fraction(1, 3) > False > > but: > > py> 1/3 == float(Fraction(1, 3)) > True > > > I expected that float-to-Fraction comparisons would convert the Fraction > to a float, but apparently they do the opposite: they convert the float > to a Fraction: > > py> Fraction(1/3) > Fraction(6004799503160661, 18014398509481984) > > > Am I the only one who is surprised by this? Is there a general rule for > which way numeric coercions should go when doing such comparisons?
Any float can be precisely represented as a Fraction. Not so in the other direction. So from that standpoint it makes sense to me to cast to Fraction when comparing. -- http://mail.python.org/mailman/listinfo/python-list
