virtualenv 101
virtualenv is a tool that allow users to create an isolated Python environment. It works by creating a working copy of Python runtime (specified by you) specific to a project without polluting other projects.
Installation
$ pip install virtualenv
Usage
$ mkdir ~/prj/envs; cd ~/prj/envs
# creating virtual env
$ virtualenv myfirstenv # use -p to specify Python runtime of your choice
# activating env
$ . myfirstvenv/bin/activate
# install other libraries, installation will stay local to the virtual env
$ pip install Flask # e.g. Flask, Django etc...
# deactivate env
$ deactivate
Note
Rather than managing the environments manually. You can use virtualenvwrapper (available via pip) to manage virtual environments.
Usage
# create env
$ mkvirtualenv myfirstenv
# activate env
$ workon myfirstenv
# deactivate env
$ deactivate
# remove env
$ rmvirtualenv myfirstenv
#list all envs
$ lsvirtualenv