hehe.py

from functools import wraps

class R(object):
    def __init__(self, a):
        self.a = a

    def post(self, f):
        setattr(self.a, 'blah', 'blah')


class A(object):
    def reg(self, f):
        self.f = f
        setattr(self, f.func_name, R(self))
        @wraps(f)
        def deco(*args, **kwards):
            print 'called'
            setattr(f, 'a', 'a')
            return f(*args, **kwards)

        return deco

a = A()

@a.reg
def some_func():
    print 'a'

@a.some_func.post
def post_func():
    print 'b'


if __name__ == '__main__':
    print a.f
    print a.some_func
    print a.blah