[Python-Dev] Distutils and Distribute roadmap (and some words on Virtualenv, Pip)

Thu Oct 8 18:35:45 CEST 2009

On 8 Oct 2009, at 18:17 , Toshio Kuratomi wrote:
>>> This is not at all how I use virtualenv. For me virtualenv is a
>> sandbox so that I don't have to become root whenever I need to 
>> install
>> a Python package for testing purposes
>> This is needing to install multiple versions and use the newly 
> installed
> version for testing.
>No it's not. It's keeping the python package *being tested* out of the 
system's or user's site-package because it's potentially unstable or 
unneeded. It provides a trivial way of *removing* the package to get 
rid of it: delete the virtualenv. No trace anywhere that the package 
was ever installed, no impact on the system (apart from the potential 
side-effects of executing the system).
The issue here isn't "multiple installed packages", it will more than 
likely be the only version of itself: note that it's a package being 
tested, not an *upgrade* being tested.
The issues solved are:
* not having to become root (solved by PEP 370 if it ever lands)
* minimizing as much as possible the impact of testing the package on 
the system (not solved by any other solution)
>> and to allow me to hop between
>> sets of installed Python packages while developing on multiple Python
>> projects.
>> This is the ability to install multiple versions and specify different
> versions for different projects you're working on.
>No, this is the ability to not needlessly clutter site-packages, keep 
them clean, tight, focused; and the ability to keep a project's 
environment (such as its dependencies) clear and repeatable. Nowhere 
was it indicated that multiple versions were involved.
Both of those *might* imply issues of multiple versions concurrently 
installed on the system, and virtualenv would incidentally solve these 
issues, but these issues are *not* the core of either use case. 
They're at best peripheral and potential.