[Python-3000] ordered dict for p3k collections?

[Adam Olsen]

On 9/14/07, Mark Summerfield <mark at qtrac.eu> wrote:
> On 2007-09-14, Nicko van Someren wrote:
> > On 11 Sep 2007, at 15:06, Mark Summerfield wrote:
> > > Is there any chance that an ordered dict will be added to Python 3's
> > > library?
> >
> > It would make sense, since one of the primary justifications for the
> > new metaclass system (PEP 3115) is to allow the metaclass to provide
> > order-preserving dictionaries to record the order in which members
> > are defined.
> >
> > > I think other people must find such things useful. There are three
> > > implementations on the Python Cookbook site, and one on PyPI, all in
> > > pure Python (plus I have my own implementation, also pure Python).
> >
> > Is there much commonality between the interfaces for these?  I'm sure
> > there are various different opinions as to the exact nature of the
> > API, particularly around any facilities for re-ordering, slicing etc.
> >       Cheers,
> >               Nicko
>
> After posting I realised that actually this isn't P3K-specific. I'd hope
> to see the collections module extended with more data structures in
> general.
>
> I put a similar post on the main python list but with no consensus so
> far...
>
> I put forward an API which is the same as dict (but any list or iterator
> returned "just happens" to work in key order) plus a few extra methods
> to exploit the ordering. I don't know how to refer to a usenet thread
> but this should get there:

That's a sorted dict.  PEP 3115 wants an insertion-ordered dict.
You're not the first to confuse them. ;)

-- 
Adam Olsen, aka Rhamphoryncus