ericsnowcurrently at gmail.com
Wed May 9 05:03:06 CEST 2012
On Tue, May 8, 2012 at 7:14 PM, Barry Warsaw <barry at python.org> wrote:
> Hi Eric,
> Great job on the latest PEP 421. I really like it.
Encouragement appreciated. :)
> A few additional
> * sys.implementation.version
> This is defined as the version of the implementation, while
> sys.version_info is the version of the language. The semantics of
> sys.version_info have been sufficiently squishy in the past, as the XXX
> implies. This PEP shouldn't try to untangle that, so I think it be better
> to represent both values explicitly in sys.implementation.
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.
> * Adding new required variables. I'd claim that it's not unduly heavyweight
> to require a new PEP to add required variables to sys.implementation. That
> hypothetical PEP will have to include things like rationale, impact on
> other implementations, etc. That seems like enough to warrant a new PEP,
> even if it's relatively succinct.
Agreed. I'll go with that for the PEP.
> I'd also make it clear that adding new variables to
> sys.implementation.metadata explicitly does *not* require a PEP.
> * In Example Metadata Value:
> "If they later have meaningful uses cases, they can be added by following
> the process described in Adding New Required Attributes."
> I'd rephrase this to "If these or any other variables are deemed to have
> meaningful use cases across all implementations, they can be moved or added
> to sys.implementation directly, following the process described in Adding
> New Required Attributes."
That's an important distinction. I'll clean it up.
> * I mildly prefer sys.implementation.name to be lower cased. My intuition is
> that to be safe, most comparisons of the value will coerce to lower case,
> which is easy enough in Python, but perhaps a bit more of a pain in C. I
> don't feel really strongly about this though. (A counter argument is that
> the value might be printed, so a case-sensitive version would be better.)
I'm not sure it makes a lot of difference. Since cache_tag will be
provided by the implementation, I don't have any strong use-cases that
would constrain the name itself. Still, my preference is for lower
case as well. I'll mull this one over.
> * Since I'm advocating to be explicit about the language version and the
> implementation version, .hexversion is probably also useful for both.
That's fine with me, and pretty trivial to do.
> * 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.
> I think sys.implementation.metadata
> should be the same type.
This I wonder about. The more I think about it, the more it fits.
I'll give it a day and if that still holds I'll work it in.
Thanks for the feedback, Barry! Feels like the PEP's getting close.
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