Manage project packages with virtualenv

While developing two or more projects at the same time, it is unavoidable to switch among projects which may use the same python package of different version. In order to resolve the headache of package management, virtualenv is designed to create isolated python environments.

Install virtualenv

Open your terminal and execute

pip3 install virtualenv virtualenvwrapper

where virtualenvwrapper is a set of extension of virtualenv.

Set environment variables

In ~/.profile, add the lines below :

export VIRTUALENVWRAPPER_PYTHON=/usr/local/bin/python3
export WORKON_HOME=$HOME/.virtualenvs
source /usr/local/bin/virtualenvwrapper.sh

Followed by reloading ~/.profile :

source ~/.profile

Some examples of usage

To create a new project environment named vision with python 3.4 support :

$ mkvirtualenv -p /usr/local/bin/python3.4 vision

In case we want to install ipython under vision environment :

pip install ipython[notebook]

To leave the environment of current project :

deactivate

To work on a existed project :

workon project_name