This was the first version of a spreadsheet generator that builds/updates Magic: the Gathering collection management spreadsheets.
It is very slow, taking ~30 minutes to create or update a spreadsheet and requires some degree of manual intervention. The code is kind of a mess and really requires that you know what is going on.
Go use Version 2 instead.
Version 2 is much faster, easier to use, and more reliable. It is a full Python rewrite that generates XLSX spreadsheets.