#!/usr/local/bin/python2
from collections import Mapping, MappingView

class DictView(Mapping, MappingView):
    __slots__ = ()

    def __getitem__(self, key):
        return self._mapping[key]

    def __iter__(self):
        return iter(self._mapping)

d = DictView({1:1, 2:2})
print d, d[2], next(iter(d))