Web-app to run python script in background

I have developed a python script that reads a .csv file and after running it produces a report.

I'm looking for a good reference on how to create a web-based app, where the user will input his/her data, this will be written into a .csv file, and, upon payment, the script will be run and the report(s) will be sent to the client.

Any helpful resource on that matter will be extremely helpful. I have a domain, however it would be helpful to know what type of hosting services I will need.

Thanks in advance!