[Python-Dev] PEP 407: New release cycle and introducing long-term support versions

[Nick Coghlan]

On Thu, Jan 19, 2012 at 9:07 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
>> I fear the day that people asking
>> questions on the tutor or python-list mailing lists will have to say (e.g.)
>> "I'm using Python 3.4.1 and standard library 1.2.7" in order to specify the
>> version they're using.
>
> Yeah, that's my biggest problem with Nick's proposal. Hopefully we can
> avoid parallel version schemes.

They're not really parallel - the stdlib version would fully determine
the language version. I'm only proposing two version numbers because
we're planning to start versioning *two* things (the standard library,
updated every 6 months, and the language spec, updated every 18-24
months).

Since the latter matches what we do now, I'm merely proposing that we
leave its versioning alone, and add a *new* identiifier specifically
for the interim stdlib updates.

Thinking about it though, I've realised that the sys.version string
already contains a lot more than just the language version number, so
I think it should just be updated to include the stdlib version
information, and the version_info named tuple could get a new 'stdlib'
field as a string.

That way, sys.version and sys.version_info would still fully define
the Python version, we just wouldn't be mucking with the meaning of
any of the existing fields.

For example, the current:

>>> sys.version
'3.2.2 (default, Sep  5 2011, 21:17:14) \n[GCC 4.6.1]'
>>> sys.version_info
sys.version_info(major=3, minor=2, micro=2, releaselevel='final', serial=0)

might become:

>>> sys.version
'3.3.1 (stdlib 12.08, default, Feb  18 2013, 21:17:14) \n[GCC 4.6.1]'
>>> sys.version_info
sys.version_info(major=3, minor=3, micro=1, releaselevel='final',
serial=0, stdlib='12.08')

for the maintenance release and:

>>> sys.version
'3.3.1 (stdlib 13.02, default, Feb  18 2013, 21:17:14) \n[GCC 4.6.1]'
>>> sys.version_info
sys.version_info(major=3, minor=3, micro=1, releaselevel='final',
serial=0, stdlib='13.02')

for the stdlib-only update.

Explicit-is-better-than-implicit'ly yours,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia