Winter of Getting Stuff Done is a seasonal theme I have set for Winter Season of 2020, based on CGP Grey's video. It's about getting stuff that I wanted to finish for some time done and not jumping onto new ideas all the time.
I've been interested in public transportation for many years, and as they're sadly paid (Luxembourg has the right idea here, DB doesn't), also the systems that are used for collecting fares. In Istanbul, a mifare desfire EV1 card called istanbulkart is used for this purpose. Here's the page for it (yes, there's a .istanbul tld).
I use public transportation every single workday, and I try to optimize my path in terms of both cost and time. (And internet connectivity, which is why I try to go for marmaray whenever I can.)
To help myself (and others) optimize in terms of cost, I wrote up a simple tool after talking about istanbulkart with a coworker today. Specifically, he was trying to decide if he wants to get a “mavi kart” (lit. blue card, a name with your picture, name and ID number on it. Only difference from anonymous card that I know is that it allows you to get a monthly subscription- “abonman”).
I had the idea to write up a quick script to get a sum of all your istanbulkart expenses in the last month, so I wrote a quick script while we were in marmaray.
(Actually, it didn't even look like this. It used floats so it was just a big jumbled mess, it didn't show card name or currency, in fact the card number was hardcoded, and it also didn't account for refunds, which is also the case on the picture above but not in the final result)
Later in the day I extended the code and cleaned it a lot, and here's the result: https://gitlab.com/a/ikmon
It's a small project that took me an hour or two to hack together, but I hope you enjoy it regardless.