On Sep 10, 2013, at 4:28 AM, Antoine Pitrou <solipsis@pitrou.net> wrote:

In http://bugs.python.org/issue18986 I proposed adding a new mapping
type to the collections module.

I would *really* like for this to start outside the standard library.
It needs to mature with user feedback before being dumped
in the collections module (which was never intended to be a
giant pile of every collection a person could think of).  

Adding yet more dictionary variants is an example of