eat excel, think pandas, out excel.
Because some people don't like pandas despite its power and they insist in doing everything in Excel. A Flask app that eats Excel files, does some processing, and outputs another Excel file because people just love Excel.
Just copy the main.py and add more routes as needed, use your own templates. I can't javascript, table was done using DataTables (https://datatables.net/). Just read the DataTables documentation and pandas.to_html for more customization.