[Python-Dev] Add a "transformdict" to collections

[Ethan Furman]

On 09/10/2013 05:26 PM, Eric V. Smith wrote:
> On 9/10/2013 6:18 PM, Ethan Furman wrote:
>> On 09/10/2013 03:12 PM, MRAB wrote:
>>> On 10/09/2013 22:46, Antoine Pitrou wrote:
>>>> On Tue, 10 Sep 2013 18:44:20 -0300
>>>> "Joao S. O. Bueno" <jsbueno at python.org.br> wrote:
>>>>> On 10 September 2013 18:06, Antoine Pitrou <solipsis at pitrou.net> wrote:
>>>>>> On Tue, 10 Sep 2013 17:38:26 -0300
>>>>>> "Joao S. O. Bueno" <jsbueno at python.org.br> wrote:
>>>>>>> On 10 September 2013 16:08, Paul Moore <p.f.moore at gmail.com> wrote:
>>>>>>>> If you provide "retain the last", I can't see any obvious way of
>>>>>>>> implementing "retain the first" in application code without in
>>>>> effect
>>>>>>>> reimplementing the class.
>>>>>>>
>>>>>>> Which reminds one - this class should obviously have a method for
>>>>>>> retrivieng the original key value, given a matching key -
>>>>>>>
>>>>>>> d.canonical('foo') -> 'Foo'
>>>>>>
>>>>>> I don't know. Is there any use case?
>>>>>> (sure, it is trivially implemented)
>>>>>
>>>>> Well, I'd expect it to simply be there. I had not thought of
>>>>> other usecases for the transformdict itself -
>>>>
>>> I had the same thought.
>>>
>>>> Well, it is not here for dict, set, etc.
>>>>
>>> In those cases the key in the dict == the key you're looking for.
>>
>> With the exception of numbers, of course (float vs int vs Decimal, etc.).
>
> They'd still be ==, wouldn't they?

Yes, but for presentation purposes not identical.

--
~Ethan~