Sending data from JavaScript to Python LOCALLY
The browsers security model prevents sending data to local processes. Your options are:

Write a browser extension that calls a python script.
Run a local webserver. Most Python web development frameworks have a simple one included.
I am writing a program that opens an html form in a browser window.  From there, I need to get the data entered in the form and use it in python code.  This has to be done completely locally.  I do not have access to a webserver or I would be using PHP.  I have plenty of experience with Python but not as much experience with JavaScript and no experience with AJAX.  Please help!  If you need any more information to answer the question, just ask. All answers are greatly appreciated.