<Steven D'Aprano – Dienstag, 14. April 2009 11:09> > I have a subclass of int where I want all the standard arithmetic > operators to return my subclass, but with no other differences: > > class MyInt(int): > def __add__(self, other): > return self.__class__(super(MyInt, self).__add__(other)) > # and so on for __mul__, __sub__, etc. > > > My quick-and-dirty count of the __magic__ methods that need to be over- > ridden comes to about 30. That's a fair chunk of unexciting boilerplate. > > Is there a trick or Pythonic idiom to make arithmetic operations on a > class return the same type, without having to manually specify each > method? I'm using Python 2.5, so anything related to ABCs are not an > option. > > Does anyone have any suggestions?
Metaclasses can be used for this purpuse, see the example for a Roman number type [1] [1] http://paste.pocoo.org/show/97258/ -- Freedom is always the freedom of dissenters. (Rosa Luxemburg) -- http://mail.python.org/mailman/listinfo/python-list
