[Python-Dev] LinkedHashSet/LinkedHashMap equivalents

[Raymond Hettinger]

> > If I read the proposal correctly, order would be determined by when
the
> > key was first encountered.  Presumably, that would mean that the
related
> > value would also be the first encountered (not overridden by
later-added
> > keys as dictated by your business requirements).
> 
> Hmmmmm....  Guess this means we need a PEP!

Or the implementation can have a switch to choose between keep-first
logic or replace logic.

The latter seems a bit odd to me.  The key position would be determined
by the first encountered while the value would be determined by the last
encountered.  Starting with [(10, v1), (20, v2), (10.0, v3)], the
ordered dictionary's items would look like [(10, v3), (20, v2)].  


Raymond