In article <[EMAIL PROTECTED]>, Arnaud Delobelle <[EMAIL PROTECTED]> wrote: > >There's a very simple way of emulating Fraction.__cmp__ in Python 3: > >def totally_ordered(cls): > def __lt__(self, other): return self.cmp(other) < 0 > def __eq__(self, other): return self.cmp(other) == 0 > def __gt__(self, other): return self.cmp(other) > 0 > cls.__lt__ = __lt__ > cls.__eq__ = __eq__ > cls.__gt__ = __gt__ > # and same with __le__, __ge__ > return cls > >@totally_ordered >class Fraction: > def __init__(self, num, den=1): > assert den > 0, "denomintator must be > 0" > self.num = num > self.den = den > def cmp(self, other): > return self.num*other.den - self.den*other.num > > >It doesn't suffer the speed penalty incurred when defining comparison >operators from __eq__ and __lt__.
That's true IIF __sub__() is not substantially slower than __cmp__(); however, your basic technique is sound and one can easily rewrite your cmp() to use some other algorithm. -- Aahz ([EMAIL PROTECTED]) <*> http://www.pythoncraft.com/ "It is easier to optimize correct code than to correct optimized code." --Bill Harlan -- http://mail.python.org/mailman/listinfo/python-list
