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

[R. David Murray]

On Tue, 10 Sep 2013 16:21:18 +0100, Nigel Small <nigel at nigelsmall.com> wrote:
> Could a more generic variant of this class work? In the same way that
> `sorted` can accept a comparison function, similar could be done for a
> dictionary-like class:
> 
> d = transformdict(key=str.lower)
> 
> Strictly speaking, this would provide case-insensitive but not
> case-preserving behaviour. For any given use case, though, a function could
> instead be supplied to "normalise" the key (upper, lower, title case, etc)
> in a way that fits that case. I can't think of many real cases where
> multiple types of capitalisation would be useful within the same dictionary.

I can:

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For network protocols you really do want to *preserve* the case.

--David