Issue 5218: Check for tp_iter in ceval:ext_do_call before overriding exception message (original) (raw)

Issue5218

Created on 2009-02-11 19:32 by gpolo, last changed 2022-04-11 14:56 by admin. This issue is now closed.

Messages (7)
msg81657 - (view)	Author: Guilherme Polo (gpolo) *	Date: 2009-02-11 19:32
Hi, I find it weird that given this sample code: def g(): yield iter(None) list(*g()) I get this traceback: Traceback (most recent call last): File "a1.py", line 3, in list(*g()) TypeError: type object argument after * must be a sequence, not generator At a minimum the exception message looks awkward to me. With the proposed patch, the new traceback would be: Traceback (most recent call last): File "a1.py", line 3, in list(*g()) File "a1.py", line 2, in g yield iter(None) TypeError: 'NoneType' object is not iterable
msg81658 - (view)	Author: Guilherme Polo (gpolo) *	Date: 2009-02-11 19:35
(Btw, the suggestion to check for tp_iter came from Antoine Pitrou. It seemed fine to me.)
msg81659 - (view)	Author: Antoine Pitrou (pitrou) *	Date: 2009-02-11 19:41
You must check tp_iter as well, not only Py_TPFLAGS_HAVE_ITER. Py_TPFLAGS_HAVE_ITER only tells you that the tp_iter field exists, not that it's non-NULL. (see the code for PyObject_GetIter() in Objects/abstract.c for an example)
msg81675 - (view)	Author: Guilherme Polo (gpolo) *	Date: 2009-02-11 21:34
Thanks for taking a look, my bad for taking so long to reply. I'm adding a new patch now. This one, besides the fix needed mentioned above, disregards tp_iter from old class instances (since they are always available and tell us nothing).
msg119296 - (view)	Author: Georg Brandl (georg.brandl) *	Date: 2010-10-21 13:47
Is this ready to commit?
msg151111 - (view)	Author: Martin Panter (martin.panter) *	Date: 2012-01-12 04:52
See also Issue 4806
msg152581 - (view)	Author: Terry J. Reedy (terry.reedy) *	Date: 2012-02-04 02:27
This is one of 4 duplicate issues, 3 with somewhat similar patches, with nearly disjoint nosy lists. Consolidating.