We have a requirement to run python scripts from Javascript. We have to pass an input String to the python script as an argument, and display the python output onto our web
Your Ajax call will be a web request (http) to the python script, so your python script needs to listen on the port for such requests and respond back.
Above mentioned method is recommended, to use simple web server inside your sample ,py or you can use an existing ones such as Flask (or many others).
FYI - for your simple task I would not recommend Django (its a big and heavy web framework with lots of bells you do not need).