New submission from Murali Ganapathy <murali@google.com>: The documentation at https://docs.python.org/3.6/library/constants.html#NotImplemented states If all attempts return NotImplemented, the interpreter will raise an appropriate exception. However this is not true for __eq__. === class Foo: def __eq__(self, other): return NotImplemented Foo() == Foo() # returns False, does not throw an exception ==== ---------- assignee: docs@python components: Documentation messages: 358719 nosy: docs@python, murali priority: normal severity: normal status: open title: Misleading documentation versions: Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue39111> _______________________________________