[Python-ideas] RFC: PEP: Add dict.__version__

[Terry Reedy]

On 1/12/2016 12:11 PM, Barry Warsaw wrote:
> On Jan 12, 2016, at 01:37 PM, Nick Coghlan wrote:
>
>> The question then becomes "Are we willing to let CPython cede high
>> memory pressure environments to more specialised Python variants?",
>> and I think the answer to that is "yes".
>
> I'm not so willing to cede that space to alternative implementations, at least
> not yet.  If this suite of ideas yields *significant* performance
> improvements, it might be a worthwhile trade-off.  But I'm not in favor of
> adding dict.__version__ in the hopes that we'll see that improvement; I think
> we need proof.
>
> That makes me think that 1) it should not be exposed to Python yet; 2) it
> should be conditionally compiled in, and not by default.  This would allow
> experimentation without committing us to long-term maintenance or an
> across-the-board increase in memory pressures for speculative gains.

New modules can be labelled 'provisional', whose meaning includes 'might 
be removed'.  Can we do the same with new internal features?

-- 
Terry Jan Reedy