On Mar 13, 11:37 am, Jack Diederich <jackd...@gmail.com> wrote: > If Fraction.__add__ returns a new object but the subclass Value is > compatible (as I would except since it is a sublcass) then just change > all references in Franction.__add__ to be more generic, ex/ > > class Franction(): > def __add__(self, other): > return self.__classs__(self.denominator + other.denominator) > > That way if __add__ is called by an instance of a subclass it will > return an instance of that subclass. >
Yes, I think the OP understands that, and also understands that he would have to do the same thing for __sub__, __div__, __rsub__, __radd__, etc. That's why I suggested that, instead of writing all that tedious code, he could write code that writes the tedious code :-) As Terence Parr of ANTLER fame asks: "Why program by hand in five days what you can spend five years of your life automating?" Pat -- http://mail.python.org/mailman/listinfo/python-list
