[Python-Dev] Making stdlib modules optional for distributions (Was: Breaking up the stdlib (Was: release cadence))

[Steve Dower]

On 07Jul2016 0624, Barry Warsaw wrote:
> On Jul 07, 2016, at 08:12 AM, Eric V. Smith wrote:
>
>> One thing to keep in mind if we do this is how it interacts with the -S
>> command line option to not include site-packages in sys.path. I currently use
>> -S to basically mean "give my python as it was distributed, and don't include
>> anything that was subsequently added by adding other RPM's (or package
>> manager of your choice)". I realize that's a rough description, and possibly
>> an abuse of -S. If using -S were to start excluding parts of the stdlib, that
>> would be a problem for me.
>
> It's an important consideration, and leads to another discussion that's
> recurred over the years.  Operating systems often want an "isolated" Python,
> similar to what's given by -I, which cannot be altered by subsequent
> installs.  It's one of the things that lead to the Debian ecosystem using
> dist-packages for PyPI installed packages.  Without isolation, it's just too
> easy for some random PyPI thing to break your system, and yes, that has really
> happened in the past.
>
> So if we go down the path of moving more of the stdlib to site-packages, we
> also need to get serious about a system-specific isolated Python.

I've done just enough research to basically decide that putting any of 
the stdlib in site-packages is infeasible (it'll break virtualenv/venv 
as well), so don't worry about that.

A "dist-packages" equivalent is a possibility, and it may even be 
possible to manage these packages directly in Lib/, which would result 
in basically no visible impact for anyone who doesn't care to update 
individual parts.

Cheers,
Steve

> Cheers,
> -Barry