For installing Fantastico usually we have to go to WHM >> Plugins then perform the usual click and install method. Using the script mentioned in the above forum we can automate the installation of Fantastico from linux command line. The “twill-sh” python script is using in the linux bash script to perform automated form submission.

For more details refer http://jackal777.wordpress.com/2012/02/22/fantastico-autoinstaller-for-cpanelwhm/