Linux check ansible version command

Open the terminal Application and type the following command:
$ ansible --version
Sample outputs:

ansible 2.4.0.0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/home/vivek/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.14 (default, Sep 23 2017, 22:06:14) [GCC 7.2.0]

I am using Ansible version 2.4.0.0 along with python version 2.7.14. I strongly suggest that you always use latest stable version. Here is a sample outputs from my Fedora Linux workstation:

Build and install latest ansible on RPM based distro

The commands are as follows:
$ git clone https://github.com/ansible/ansible.git
$ cd ./ansible
$ make rpm
$ sudo rpm -Uvh ./rpm-build/ansible-*.noarch.rpm

Install latest ansible on a Ubuntu Linux based distro

Type the following apt-get command:
$ sudo apt-get update
$ sudo apt-get install software-properties-common
$ sudo apt-add-repository ppa:ansible/ansible
$ sudo apt-get update
$ sudo apt-get install ansible

Install latest ansible on an Apple macOS X Unix based distro

$ brew install ansible

Install latest version of ansible on a FreeBSD

Type the following pkg command:
# pkg install ansible

Install latest version of ansible on a Fedora Linux

Run the following dnf command:
$ sudo dnf install ansible

Install latest version of ansible on an Arch Linux

Type the following pcman command:
$ sudo pcman -S ansible

Install latest version of ansible on a Debian Linux

Type the following apt command:
# echo 'deb http://ppa.launchpad.net/ansible/ansible/ubuntu trusty main' >> /etc/apt/sources.list
# apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 93C4A3FD7BB9C367
# apt-get update
# apt-get install ansible

Conclusion

You can grab the latest version of Ansible by visiting this page. I also recommend that you read the official documents here.