[Python-Dev] Python install layout and the PATH on win32 (Rationale part 1: Regularizing the layout)

Sat Mar 24 04:22:04 CET 2012

On Mar 23, 2012 3:53 PM, "Carl Meyer" <carl at oddbird.net> wrote:
>> Hi PJ,
>> On 03/23/2012 12:35 PM, PJ Eby wrote:
> > AFAICT, virtualenvs are overkill for most development anyway. If you're
> > not using distutils except to install dependencies, then configure
> > distutils to install scripts and libraries to the same directory, and
> > then do all your development in that directory. Presto! You now have a
> > cross-platform "virtualenv". Want the scripts on your path? Add that
> > directory to your path... or if on Windows, don't bother, since the
> > current directory is usually on the path. (In fact, if you're only
> > using easy_install to install your dependencies, you don't even need to
> > edit the distutils configuration, just use "-md targetdir".)
>> Creating and using a virtualenv is, in practice, _easier_ than any of
> those alternatives,

Really? As I said, I've never seen the need to try, since just installing
stuff to a directory on PYTHONPATH seems quite easy enough for me.
> that the "isolation from system site-packages" feature is quite popular
> (the outpouring of gratitude when virtualenv went isolated-by-default a
> few months ago was astonishing), and AFAIK none of your alternative
> proposals support that at all.

What is this isolation for, exactly? If you don't want site-packages on
your path, why not use python -S?
(Sure, nobody knows about these things, but surely that's a documentation
problem, not a tooling problem.)
Don't get me wrong, I don't have any deep objection to virtualenvs, I've
just never seen the *point* (outside of the scenarios I mentioned), and
thus don't see what great advantage will be had by rearranging layouts to
make them shareable across platforms, when "throw stuff in a directory"
seems perfectly serviceable for that use case already. Tools that *don't*
support "just throw it in a directory" as a deployment option are IMO
unpythonic -- practicality beats purity, after all. ;-)
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