It is certainly the case that isinstance(True, int) returns True, even today.
I got a bug for not remembering it, a couple of years ago: https://jpscaletti.com/p/8/true-false-one-and-zero
alt Hacker News
I got a bug for not remembering it, a couple of years ago: https://jpscaletti.com/p/8/true-false-one-and-zero