python: what's the difference between pythonbrew and virtualenv?

Question

I am new to python and I am planning to learn django. I had a bit of experience with ruby (not rails) and I am familiar with RVM however I don\'t understand the

Answer 1

For what its worth I've never heard of PythonBrew before, but I know (and love) virtualenv.

Virtualenv is used to create separate environments, based on the python install you have on your machine. That is, if I have python 2.7 I can create a number of isolated python 2.7 environments, but I can't create python2.6 environments.

According to this (which I found via google) Pythonbrew seems to be focussed on installing other python versions. So I guess you would use 'brew to install py2.6 and 2.7 and then virtualenv to create environments for each.

Or, it seems, 'brew can create the environments too, using virtualenv.

Why a different python interpreter is not really an isolated environment.

Each python installation has a set of packages (placed in 'site-packages' I think). If you install a new package it is added to this set, and available for all your python code.

This can be a problem if you have one project that you build on Django0.96 and you want to start a new project using Django1.3. If you just update your system version of Django that would affect you old project too.

With virtualenvs you could create one environment with Django1.3 and another with Django0.96, both being python2.7. If you were OK with running your old project in python2.6 and the new one in python2.7 you could do that too, but what about your next two projects using diffenret versions from Django-Trunk then?