New submission from Serhiy Storchaka: For now len() raises ValueError if __len__() returns small negative integer and OverflowError if __len__() returns large negative integer.
>>> class NegativeLen: ... def __len__(self): ... return -10 ... >>> len(NegativeLen()) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: __len__() should return >= 0 >>> class HugeNegativeLen: ... def __len__(self): ... return -sys.maxsize-10 ... >>> len(HugeNegativeLen()) Traceback (most recent call last): File "<stdin>", line 1, in <module> OverflowError: cannot fit 'int' into an index-sized integer Proposed patch makes it always raising ValueError. ---------- components: Interpreter Core messages: 289779 nosy: Oren Milman, haypo, serhiy.storchaka priority: normal severity: normal stage: patch review status: open title: Avoid raising OverflowError in len() when __len__() returns negative large value type: enhancement versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue29839> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
