The quirks they don't put on the brochure

== checks value equality. is checks identity (same object in memory). Use is only for None, True, and False.

Quirk #6: CPython caches small integers (-5 to 256), so 256 is 256 can be True while larger numbers might not be. Rely on == for numbers.

Quirk #7: True and False are subclasses of int. Yes, really: True + True == 2. The language is trolling you.