How to interact: Python with HTML

See more:

HTML

Python

Django

interaction

I have a localhost with a simple html form ("test.html") and a program written in python ("program.py") I'd like to do this:

1º: Pass the form's field submitted by the user to the program and make it run: "test.html" --> "program.py"

2º: The program process that data and give an answer. I'd like to pass that answer to the html file to show it in localhost: "program.py" --> "test.html"

What I have tried:

I read a flask and a Django's tutorial but I couldn't understand how to do exactly this... I read about "cgi", a python library which can get data from an html form but through an indepent script, (At least I understood this way) Is there a way, please?