Gather or update ansible facts
Ansible facts are very useful data related to your remote systems. You can access this data in the ansible_facts variable.
This is how to gather or update known facts from the specific server with one command. In this example there is usage of specific python as well. If you want to you can use it without -e parameter.
ansible -i /etc/ansible/hosts yourserver.yourdomain.com -m gather_facts -e 'ansible_python_interpreter=/usr/bin/python'