Pass information from javascript to django app and back

Question

So I'm trying to basically set up a webpage where a user chooses an id, the webpage then sends the id information to python, where python uses the id to query a database, and then returns the result to the webpage for display.

I'm not quite sure how to do this. I know how to use an ajax call to call the data generated by python, but I'm unsure of how to communicate the initial id information to the django app. Is it possible to say, query a url like ./app/id (IE /app/8), and then use the url information to give python the info? How would I go about editing urls.py and views.py to do that?

Thanks,