query python code from a web page and output back to web page

I'm sure this is basic for many of you. I'm new to programming and have used Python 2.7 to create a script that takes in command line variables from a user (postcodes, cities, dates etc), searches various Excel files (circa 5m records) and returns the resulting query as a .csv file (which is then mail merged to send letters out).

It works fine, though I run it from the command line, locally. I now would like to create a web page so that my friend can also use it. They would type in, or select from drop-downs, the variables, hit submit, the script would run on a remote server and return the resulting list to (a) the web page and (b) offer to download as a csv.

I've been looking around to try and work out the various 'bits of LEGO' I need to pull it together to take it from a single-user command line experience to a multiple user web-based one. I'm more than happy learning the packages, just not sure which direction to go. I've tried initial looks at Django, Javascript, html, sqLite, but not sure how I should proceed. I'd of course like to re-use the Python code as it works! Can anyone point me in a direction or two please ...?

Thanks in advance