http://adamj.eu/tech/2014/07/12/some-ansible-hints/

pip.yml

---
- name: pip - install packages
  pip: name={{ item.name|default(item) }}
       {% if item.version|default('') > '' %}
         version={{ item.version }}
       {% else %}
         state=latest
       {% endif %}
  with_items:
    - MySQL-python
    - { name: Django, version: 1.6.5 }