Setting up virtualenv

In environments where you don't have root access virtualenv and virtualenvwrapper can be extremely useful to satisfy dependencies and easily switch between different environments.

Installation

Add the following lines to your ~/.bashrc, where VENVPATH should be replaced with the full path to where you intend to keep everything associated with the virtual environments and all references to Python should be replaced with the version you'll be using.

# User specific aliases and functions
export VENVPATH=$HOME/opt
export PATH=$PATH:$VENVPATH/Python/bin
export PYTHONPATH=$VENVPATH/Python/lib/python2.6/site-packages
source /VENVPATH/Python/bin/virtualenvwrapper.sh
export WORKON_HOME=$VENVPATH/.virtualenvs

Then execute the following, again replacing all references to Python 2.6 with the system version:

$ export VENVPATH=$HOME/opt
$ source ~/.bashrc >& /dev/null && mkdir -p $VENVPATH/Python/lib/python2.6/site-packages
$ easy_install --prefix=$VENVPATH/Python pip
$ pip install virtualenvwrapper --install-option="--prefix=$VENVPATH/Python/" && source ~/.bashrc

$ mkvirtualenv --python=python2.6 --no-site-packages topo

Or with your custom Python build:

module unload python && mkvirtualenv --no-site-packages --python=..../bin/python topo

Associated Links:

Overview of living with virtualenv and using GitHub

Making life even better: Virtualenvwrapper

Installing virtualenvwrapper without root access.

Virtualenv hooks, allow you to add hooks when activating or deactivating an environment (e.g. switch to the topographica directory).