Why are there no ordered dictionaries?

[Christoph Zwerschke]

Bengt Richter schrieb:

> OTOH,
>  >>> {}[:]
>  Traceback (most recent call last):
>    File "<stdin>", line 1, in ?
>  TypeError: unhashable type
> I.e., slices are not valid keys for ordinary dicts, and slices tie in
> very well with the ordered aspect of ordered dicts, so that's an
> argument for permitting it via the indexing syntax, not just items[:]
> or items()[:] which have related but not identical semantics.

I see it like that. BTW, the above error message is pretty bad.

 > I wonder who is going to use it for what.

I think re-ordering will be a very rare use case anyway and slicing even 
more. As a use case, I think of something like mixing different 
configuration files and default configuration parameters, while trying 
to keep a certain order of parameters and parameters blocks.

-- Christoph