Terry J. Reedy <tjre...@udel.edu> added the comment: I retested and iter(ob) (1) apparently raises 'not iterable' only when it can find neither __iter__ nor __getitem__. It (2) raises 'non-iterator', as above, when it finds __iter__, calls its, and get a non-iterator. (3) Exceptions in __iter__ are passed through. (If it finds and wraps __getitem__, errors only appear during iteration.)
The current patch for assignment unpacking catches case (1) with "v->ob_type->tp_iter == NULL && !PySequence_Check(v))". Removing this would catch case (2) and incidentally case (3) TypeErrors. Not catching user TypeErrors would require looking at the message. I intentionally am not proposing to remove the TypeError check. Presuming the existence of a PyErr_' function to get exception messages, we could simply prefix the existing message with a short 'Cannot unpack. ' The same could be done for the other cases in msg307999, but I don't know if they are subject to the same need. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32259> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
