virtualenvwrapper and Python 3

On Ubuntu; using mkvirtualenv -p python3 env_name loads the virtualenv with python3.

Inside the env, use python --version to verify.

You can make virtualenvwrapper use a custom Python binary instead of the one virtualenvwrapper is run with. To do that you need to use VIRTUALENV_PYTHON variable which is utilized by virtualenv:

$ export VIRTUALENV_PYTHON=/usr/bin/python3
$ mkvirtualenv -a myproject myenv
Running virtualenv with interpreter /usr/bin/python3
New python executable in myenv/bin/python3
Also creating executable in myenv/bin/python
(myenv)$ python
Python 3.2.3 (default, Oct 19 2012, 19:53:16) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.

If you already have python3 installed as well virtualenvwrapper the only thing you would need to do to use python3 with the virtual environment is creating an environment using:

which python3 #Output: /usr/bin/python3
mkvirtualenv --python=/usr/bin/python3 nameOfEnvironment

Or, (at least on OSX using brew):

mkvirtualenv --python=`which python3` nameOfEnvironment

Start using the environment and you'll see that as soon as you type python you'll start using python3

The latest version of virtualenvwrapper is tested under Python3.2. Chances are good it will work with Python3.3 too.