[Python-3000] bytes and dicts (was: PEP 3137: Immutable Bytes and Mutable Buffer)

[Guido van Rossum]

Well, maybe this is a good enough argument to give up. If the best we
can say is that having a bytes and a str as keys *may* cause a
TypeError on lookups, I'm not sure it is worth it to try to raise the
probability that it'll actually be raised...

--Guido

On 9/28/07, Jim Jewett <jimjjewett at gmail.com> wrote:
> On 9/27/07, Guido van Rossum <guido at python.org> wrote:
> > On 9/27/07, Jim Jewett <jimjjewett at gmail.com> wrote:
>
> > > Should a TypeError be raised as soon as you try to put a bytes and a
> > > string in the same dict, even if they don't happen to hash equal?
>
> > Good idea, if you can figure out a way to implement this efficiently.
>
> In news that may surprise no one, there were corner cases...
>
> (1)  Does it have to raise the TypeError eagerly in all cases, or is
> it OK to do so only when its easy?
>
> For example, would it be OK to stop verifying once some keys have been deleted?
>
> (2)  Is the restriction "sticky" for a dict, or based on current contents?
>
> Current contents makes sense, but ...
>
> If code clears an existing dict rather than creating a new one, then
> that specific dict is probably a communication channel, and the API
> should specify whether it takes bytes or characters.
>
> -jJ
>


-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)