[Python-Dev] PEP 455: TransformDict (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Fri Sep 13 23:45:16 CEST 2013

On Fri, 13 Sep 2013 23🔞39 +0300 Serhiy Storchaka <storchaka at gmail.com> wrote:

13.09.13 23:02, Antoine Pitrou написав(ла): > On Fri, 13 Sep 2013 16:54:01 -0300 > "Joao S. O. Bueno" <jsbueno at python.org.br> wrote: >> I see the PEP does not contemplate a way to retrieve the original key >> - like we've talked about somewhere along the thread. > > Indeed. If that's important I can add it. I was hoping to keep very > close to the MutableMapping API, to make the PEP as few > controversial as possible.

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'

Regards

Antoine.

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