Please Note : These steps demonstrated and tested on Ubuntu 15.04 but they will work same on other Ubuntu and Debian based distributions .

Setup

apt-get install build-essential

# Install Python Development package and pip 

apt-get install python2.7-dev python-setuptools
sudo easy_install pip

Now Install virtualenv

sudo pip install virtualenv

After Install You can use virtualenv to setup virtual environment

cd your_project_folder
virtualenv venv

then activate the virtual environment

source venv/bin/activate

Before using virtualenv freeze pip and pipe that to requirements.txt file

pip freeze > requirements.txt

then after activation virtualenv install all dependencies using pip

pip install -r requirements.txt

additionally you can install virtualenvwrapper , which provide awesome setup of tools which make working with virtualenv easy and pleasant .

read more about virtualenvwrapper http://virtualenvwrapper.readthedocs.org/en/latest/install.html

to deactivate virtual environment :

deactivate

Useful Links

1 .virtualenvs
2 .virtualenvwrapper

I hope this post will help you to setup virtual environment in you system . thanks for reading .