multiple python versions

[Shlomo Solomon]

On Thu, 22 Jul 2021 19:50:46 +0300
Omer Zak <w1 at zak.co.il> wrote:

> Why do you want to avoid having to re-install modules for each
> version/environment?
> 
The short answer: too much work

The slightly longer answer: Although there are certainly changes
between versions of Python and/or modules, most modules DO work when
moving to a newer version of Python. I don't remember re-installing
everything when upgrading to a newer version of Python.

But here, my problem is not upgrading, but keeping both versions.




> In the general case, a module version is compatible only with a subset
> of Python versions, due to API changes from Python version to Python
> version.
> 
> You also want to let each project decide with which module version it
> wants to work, due to potential incompatibilities between module
> versions (it is no accident that pip freeze preserves installed module
> versions).
> 
> 
> On Thu, 2021-07-22 at 19:37 +0300, Shlomo Solomon wrote:
> > Omer Zak <w1 at zak.co.il> wrote:
> > > The answer to your prayers is pyenv.
> > > It allows you to install multiple Python versions in parallel, and
> > > for
> > > each version you can maintain several virtualenvs.
> > 
> > Dan Yasny <dyasny at gmail.com> wrote:
> > > How about using virtualenv for alternative versions?
> > 
> > Yes, I know about pyenv and virtualenv, but wouldn't I have to
> > re-install modules for each version/environment? That's what I'm
> > trying
> > to avoid.



-- 
Shlomo Solomon
http://the-solomons.net
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