[Python-Dev] Edits to Metadata 1.2 to add extras (optional dependencies)

[R. David Murray]

On Tue, 28 Aug 2012 11:17:08 -0400, Donald Stufft <donald.stufft at gmail.com> wrote:
> On Tuesday, August 28, 2012 at 11:07 AM, "Martin v. Löwis" wrote:
> 
> > > What happens when it expires? Is that name freed up for future use?
> >  
> >  
> > Yes, exactly.
> >  
> > > I
> > > think that freeing up the name is likely to be a bad idea since we can't go
> > > backwards in time (as you alluded to later about not deleting them), so
> > > what does expiration do?
> > >  
> >  
> >  
> > Why would it require going backwards in time? Existing usages of the
> > extension just become invalid, e.g. with the consequence that you can't
> > upload the package to PyPI anymore unless you remove the extension,
> > or re-register it.
> >  
> > If the extension is in active use, somebody certainly will make sure it
> > stays registered. Expiration is to free up names that are not in active
> > use, but are otherwise reasonable names for metadata fields (say,
> > Requires-Unicode-Version).
> 
> What do you do with packages that have already been uploaded with
> requires-unicode-version once it expires? If the point of a registry is
> to remove ambiguity from what any particular key means, won't expiring
> and allowing reregistration of an in use name (even if it's no longer being
> uploaded, but is still available inside of a package) reintroduce that same
> ambiguity? How will we know that requires-unicode-version from a package
> uploaded a year ago and has since expired is different than requires-unicode-version
> from a package uploaded yesterday and has been reregistered?  

Ah, that's a better phrasing of the same concern I had but couldn't
figure out how to articulate.

I don't recall any RFC registries that have expiration dates for
entries.  Are there any?

RFC registries usually have an organization vetting the entries,
whereas it seems like we want this to be an open registry.  Note that the
MIME-type specification allows for "vendor types", which is a namespace
mechanism and allows delegation of vetting authority.  That sounds
more like Nick's proposal.  (I'm sure there is some way to solve the
ambiguity issue.)

We could still have a (vetted) registry for "official" names, if
we wanted.  That would follow the MIME model.  Or we can still have a
separate registry, but only "qualified" (namespaced) names are open for
anyone to register, without any expiration dates.

--
R. David Murray

If you like the work I do for Python, you can enable me to spend more
time doing it by supporting me here:  http://gittip.com/bitdancer