This is the 3rd video in the CSV/Spreadsheet manipulation with programming mini-series. This video teaches you how to do horizontal manipulation alongside vertical. This means you can use data from other rows as well in your calculations.
The main reason why you would want to use a programming language like python to help you with your spreadsheets is it can actually become easier to use python than a typical spreadsheet program. This happens when you want to use extensive formulas or even apply a little bit of coding logic to the spreadsheet’s cells.