Python indexer sample like C#

gistfile1.py

class indexer(object):
    def __init__(self, getter, setter=None, deleter=None, doc=None):
        self._getter = getter
        self._setter = setter
        self._deleter = deleter
        self.__doc__ = doc or getter.__doc__
        self._delegates = {}

    def setter(self, func):
        self._setter = func
        return self

    def deleter(self, func):
        self._deleter = func
        return self

    def __get__(self, instance, owner):
        if instance is None:
            return self
        else:
            if instance not in self._delegates:
                self._delegates[instance] = ListLike(instance, self._getter, self._setter, self._deleter)
            return self._delegates[instance]

    def __set__(self, instance, value):
        raise NotImplementedError()

    def __delete__(self, instance):
        raise NotImplementedError()


class ListLike(object):
    def __init__(self, instance, getter, setter, deleter):
        self.instance = instance
        self.getter = getter
        self.setter = setter
        self.deleter = deleter

    def __getitem__(self, key):
        return self.getter(instance, key)

    def __setitem__(self, key, value):
        return self.setter(instance, key, value)

    def __delitem__(self, key):
        return self.deleter(instance, key)


class Sample(object):
    @indexer
    def a(self, key):
        return key

    @indexer.setter
    def a(self, key, value):
        print key, value