Keep Constant Variables between Python and JavaScript

Question

I need a way to have python and JavaScript code interact so that
A) after a JavaScript input, it runs python code.
And
B) a variable in the JavaScript code is recognized in python, and vise versa.
Thanks

Answer 1

I would do it with php or django and xml requests. shell_exec() executes shell commands but also returns the content that the python program outputs.

For nodejs
https://github.com/sindresorhus/execa#readme

Send the variable with xml request and pass it in the command line argument when executing python program.

Answer 2

How do I set this all up ?