test_mixin.py

class Root(object):
    def setup(self):
        print 'Root.setup'


class Base(Root):
    def setup(self):
        print 'Base.setup'
        super(Base, self).setup()


class Mixin(object):
    def setup(self):
        print 'Mixin.setup'
        super(Mixin, self).setup()


class Foo(Mixin, Base):
    pass
  
 
foo = Foo()
foo.setup()