Ansible is best used from a checkout.
It runs as you (not root) and it has minimal python dependencies.
Python pip dependency install with pip:
sudo pip install paramiko PyYAML Jinja2 httplib2 six
Next, clone the Ansible repo from GitHub:
cd ~/Documents
git clone git://github.com/ansible/ansible.git --recursive
cd ansible
Finally, add the ansible initialization script line to your ~/.bashrc or ~/.zshrc :
source ~/Documents/ansible/hacking/env-setup
Restart your terminal session, and test with
ansible --version