I'm a student, and I have a project to build an application (Visual analytics tool) that takes a Microsoft Excel file, cleans the data, and visualizes it. Also, the app should allow the user to filter and interact with it.

1- should I make it desktop application or web application? : I'm leaning toward (desktop)

2- D3.js OR Python?

3- better excel or CSV?

I'm a beginner Inspiration for interaction and look of the app: eventflow application.