System specific variables in ansible

Well you can set in three ways

1. http://docs.ansible.com/intro_inventory.html#list-of-behavioral-inventory-parameters ansible_python_interpreter=/usr/bin/python2 this will set it per host
2. Set it host_vars/ ansible_python_interpreter: "/usr/bin/python2" this will set it per host
3. set it for all nodes in the file group_vars/all (you may need to create the directory group_vars and the file all) as ansible_python_interpreter: "/usr/bin/python2"

Hope that helps