How to make a webpage display dynamic data in real time using Python?

I am working on making a GUI front end for a Python program using HTML and CSS (sort of similar to how a router is configured using a web browser). The program assigns values given by the user to variables and performs calculations with those variables, outputting the results. I have a few snags to work out:

1. 
   

   How do I design the application so that the data is constantly updated, in real-time? I.e. the user does not need to hit a "calculate" button nor refresh the page to get the results. If the user changes the value in a field, all other are fields simultaneously updated, et cetera.

   
   


2. 
   

   How can a value for a variable be fetched from an arbitrary location on the internet, and also constantly updated if/when it is updated at the source? A few of the variables in the program are based on current market conditions (e.g. the current price of gold). I would like to make those values be automatically entered after retrieving them from certain sources that, let us assume, do not have APIs.

   
   


3. 
   

   How do I build the application to display via HTML and CSS? Considering Python cannot be implemented like PHP, I am seeking a way to "bridge the gap" between HTML and Python, without such a "heavy" framework like Django, so that I can run Python code on the server-side for the webpage.

   
   

I have been looking into this for a quite some time now, and have found a wide range of what seem to be solutions, or that are nearly solutions but not quite. I am having trouble picking what I need specifically for my application. These are my best findings:

Werkzeug - I believe Werkzeug is the best lead I have found for putting the application together with HTML and Python. I would just like to be reassured that I am understanding what it is correctly and that is, in fact, a solution for what I am trying to do.

WebSockets - For displaying the live data from an arbitrary website, I believe I could use this protocol. But I am not sure how I would implement this in practice. I.e. I do not understand how to target the value, and then continuously send it to my application. I believe this to be called scraping?