python-chainmap

Backport/clone of ChainMap for py26, py32, and pypy3

This module is a polyfill implementing 'ChainMap' for reasonably-recent versions of Python that do not have 'collections.ChainMap' --namely, Python 2.6, Python 3.2, and PyPy3 releases based on Python 3.2. (It will also work as expected on Python 2.7, PyPy, and Python 3.3 and higher, but it is not needed there since those verions' 'collection' modules contains a 'ChainMap' implementation.)