PEP 372 -- Adding an ordered directory to collections

[Ben Finney]

Armin Ronacher <armin.ronacher at active-4.com> writes:

> This PEP proposes an ordered dictionary as a new data structure for
> the ``collections`` module, called "odict" in this PEP for short.

A welcome addition.

Since we're not proposing a built-in type, could we choose a name that
is more explicit, and consistent with the types in 'collections'
already. I'd prefer one of the following:

  collections.ordereddict
  collections.ordered_dict


Other (minor) comments:

>     The key is not moved but assigned a new value in place.  This is
>     consistent with existing implementations and allows subclasses to
>     change the behavior easily::
> 
>         class movingcollections.odict):

Something is missing in the above line of code. It's invalid as-is,
but I don't know which of the many possible replacements is intended.

> Why is there no ``odict.insert()``?

Thank you for this design decision; I agree entirely that the correct
solution is to resequence and create a new ordered dict from the
result.

> A poorly performing example implementation of the odict written in
> Python is available:
> 
>     `odict.py <http://dev.pocoo.org/hg/sandbox/raw-file/tip/
> odict.py>`_

This seems to be a victim of errant line-breaking, resulting in the
wrong URL.

-- 
 \        “The reason we come up with new versions is not to fix bugs. |
  `\                     It's absolutely not.” —Bill Gates, 1995-10-23 |
_o__)                                                                  |
Ben Finney