An attempt to implement ChainMap in python 2.7 like python 3.3
The main purpose was for experimenting only. Reusing the cPython implementation (with only few change) could be a better solution if someone plans to use ChainMap in production. See: https://github.com/python/cpython/blob/master/Lib/collections/__init__.py
The goal is to mimick the behaviour of collections.ChainMap.
$ python2
Python 2.7.8 (default, Jul 4 2014, 13:08:34)
[GCC 4.9.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import chainmap
>>> c = chainmap.ChainMap({"a": 1, "b": 2}, {"c": 3, "b": "ignored"})
>>> d = c.new_child()
>>> e = c.new_child()
>>> e.maps[0]
{}
>>> e.maps[-1]
{'c': 3, 'b': 'ignored'}
>>> d['b']
2
>>> d['b'] = 100
>>> d['b']
100
>>> del d['b']
>>> d['b']
2
>>> list(d)
['a', 'c', 'b']
>>> 'c' in d
True
>>> 'x' in d
False
>>> len(d)
3
>>> d.items()
[('a', 1), ('c', 3), ('b', 2)]
>>> dict(d)
{'a': 1, 'c': 3, 'b': 2}
Target interface: https://docs.python.org/3/library/collections.html#chainmap-objects
in root dir:
$ make check
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. The text of the license can be found in LICENCE file.