Added labels in the same style of the more recent files, but I didn't do much else other than read the chapter again while doing so.
Oh look, I did find something to change in 9.1, I change the random.choice() from a list of possible hashes to hashlib.algorithms, which is just another list of possible hashes, I suppose, but it's more future-compatible.
Added some spacing, subtitle comments for the sections, etc. Reading through this gave me an idea for an application to handle parking fees.