This post from Leon Cowle reminded me of one of the weirder and technically pleasing projects of my career. Many details here will be incorrect, not because of an NDA but because my memory is bad. We had several thousand decoders we could sell to a customer if we changed their config, which required flashing new software. To do that, a signal is sent to the decoder on its RS232 port in the first few seconds of booting to stop the boot sequence and then a series of commands is issued via RS232.

Like much of this site, this is a note to myself to remember that the insert_one method of a pymongo client modifies the input dictionary to add an _id key if it doesn’t contain one: from pymongo import MongoClient client = MongoClient(...) d = {"a": 1, "b": 2} print(d) client['db']['collection'].insert_one(d) print(d) yields this result: {'a': 1, 'b': 2} {'a': 1, 'b': 2, '_id': ObjectId('68054685b245fb3775304c31')}