New submission from Harald Husum <harald.hu...@gmail.com>:
https://docs.python.org/3/reference/expressions.html#membership-test-operations > For container types such as list, tuple, set, frozenset, dict, or > collections.deque, the expression `x in y` is equivalent to `any(x is e or x > == e for e in y)`. Yet: ```py import pandas as pd import numpy as np pd_0_dt = pd.Timedelta(0) np_0_dt = np.timedelta64(0) cm = (pd_0_dt, np_0_dt) d1 = {np_0_dt: pd_0_dt} d2 = {pd_0_dt: np_0_dt} def test_membership_doc_claim(candidate_members, dct): for m in candidate_members: if m in dct: assert any(m is e or m == e for e in dct) if any(m is e or m == e for e in dct): assert m in dct if __name__ == "__main__": test_membership_doc_claim(cm, d1) # Fails test_membership_doc_claim(cm, d2) # Fails ``` Not too surprised, given the td.__hash__() implementation differs between these classes, but they are considered equal none the less. Unsure whether it is the dict implementation or the doc claim that needs to budge here. ---------- assignee: docs@python components: Documentation messages: 406485 nosy: docs@python, eric.araujo, ezio.melotti, harahu, mdk, willingc priority: normal severity: normal status: open title: Misleading membersip expression documentation type: behavior versions: Python 3.8 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45832> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
