# -*- coding: utf-8 -*- class TreeGenomMixin(object): def __unicode__(self): return super(TreeGenomMixin, self).__unicode__() + u" with wooden leg" class Cat(object): def __unicode__(self): return u"a cat" class Dog(object): def __unicode__(self): return u"a dog" class GeneticallyModifiedCat(Cat, TreeGenomMixin): pass class GeneticallyModifiedDog(TreeGenomMixin, Dog): pass cat = GeneticallyModifiedCat() dog = GeneticallyModifiedDog() print unicode(cat) print unicode(dog)