New submission from João Henrique Pimentel <joaozinho@gmail.com>: The second parameter (classinfo) of the issubclass built-in function can be a Tuple and, starting from 3.10, it can be a Union Type as well. The documentation states that in these cases "every entry in classinfo will be checked", but it doesn't explain if the check is AND (all) or OR (any). In contrast, the documentation of isinstance is clear: "return True if object is an instance of *any* of the types". Here's a possible rewriting that reduces the odds of incorrect interpretations, based on the text of isinstance: ORIGINAL: "in which case every entry in classinfo will be checked" PROPOSAL: "in which case return True if class is a subclass of any entry in classinfo" ---------- assignee: docs@python components: Documentation messages: 393684 nosy: docs@python, joaozinho priority: normal severity: normal status: open title: issubclass documentation doesn't explain tuple semantic type: enhancement versions: Python 3.10, Python 3.11, Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue44135> _______________________________________