[Python-Dev] PEP 455: TransformDict

[Ethan Furman]

On 09/13/2013 02:45 PM, Antoine Pitrou wrote:
> Serhiy Storchaka wrote:
>>
>> I think that's important. As OrderectDict has additional methods besides
>> the MutableMapping API, so TransformDict should provide useful
>> specialized methods.
>
> Ok, I have a better (IMO) proposal:
>
>      >>> d = TransformDict(str.casefold, {'Foo': 1})
>      >>> d.getitem('foo')
>      ('Foo', 1)
>      >>> d.getitem('bar')
>      Traceback (most recent call last):
>        File "<stdin>", line 1, in <module>
>      KeyError: 'bar'

-1

When I want the canonical key, I'm not going to care about the value; and if I do, it's easy enough to get.

--
~Ethan~