If you are going to write/edit scores, it's always better/faster to edit files locally, test them until you're happy with the changes and then upload the scores to your web host using FTP.
Or maybe you just want to play with it for a while and you don't have or don't want to use your web hosting... whatever.
To have a local web server to test the app locally, you either need:
- Using Python - Here a sample article explaining how to do it.
- XAMPP
- PHP
- ... or any other you may find looking for my_operating_system local web server on your search engine of choice.