[Python-Dev] PEP 405 (pyvenv) and system Python upgrades

[Carl Meyer]

On 05/05/2012 02:38 AM, Vinay Sajip wrote:
> Nick Coghlan<ncoghlan<at>  gmail.com>  writes:
>
>> Personally, I expect that "always update your virtual environment
>> binaries after updating the system Python to a new point release" will
>> itself become a recommended practice when using virtual environments.
>
> Of course, the venv update tool will need to only update environments which were
> set up with the particular version of Python which was updated. ISTM pyvenv.cfg
> will need to have a version=X.Y.Z line in it, which is added during venv
> creation. That information will be used by the tool to only update specific
> environments.

I don't think the added "version" key in pyvenv.cfg is needed; the 
"home" key provides enough information to know whether the virtualenv 
was created by the particular Python that was upgraded.

The "version" key could in theory be useful to know whether a particular 
venv created by that Python has or has not yet been upgraded to match, 
but since the upgrade is trivial and idempotent I don't think that is 
important.

Carl