[Python-Dev] sys.implementation

[Eric Snow]

On Wed, May 9, 2012 at 10:39 AM, Barry Warsaw <barry at python.org> wrote:
> On May 08, 2012, at 09:03 PM, Eric Snow wrote:
>>Definitely tangled.  So, sys.implementation.version and
>>sys.implementation.lang_version?  Also, my inclination is to not have
>>a sys.version equivalent in sys.implementation for now, in the
>>interest of keeping things as bare-bones as possible to start.
>
> I think it would be fine, if PEP 421 was clear about the semantics of
> sys.implementation.version and was silent about trying to disentangle the
> semantics of sys.version.  IOW, the PEP can say that the semantics of
> sys.version are fuzzy, but not try to clear it up.  Then it would be explicit
> (as it already is) that sys.implementation.version describes the version of
> the implementation, not the version of the language compliance.
>
> If the latter is useful later, then it can use the PEP 421 described process
> to propose a new sys.implementation value that describes a language compliance
> variable.

Whoops.  I meant that I'm okay with having sys.implementation.version
and sys.implementation.lang_version, both as analogs to
sys.version_info.  My inclination is to not include the analog to
sys.version.  However, with the way that you put it, I think you're
right that we could put off the lang_version attribute for later.

>>>  * I've said before that I think the keys in sys.implementation should be
>>>   locked down (i.e. not writable).
>>
>>I've been on and off about this.  It's certainly not too hard to do,
>>it makes sense, and I don't see a lot of reason not to do it.  I'll
>>give it a go.
>
> Maybe it doesn't matter.  We're all adults here.  I think there are two good
> choices.  Either the PEP explicitly describes sys.implementation as immutable,
> or it is silent about it.  IOW, I don't think the PEP should explicitly allow
> sys.implementation to be mutable.

Agreed.

-eric