Issue 1339007: shelve.Shelf.del throws exceptions (original) (raw)

Issue1339007

Created on 2005-10-26 23:30 by dairiki, last changed 2022-04-11 14:56 by admin. This issue is now closed.

Messages (4)
msg26742 - (view)	Author: Geoffrey T. Dairiki (dairiki)	Date: 2005-10-26 23:30
Python calls an object's __del__ method, even if the objects __init__ method was unsuccessful (i.e. __init__ terminated via exception.) Because of this, if there is an error while attempting to open a Shelf, the destructor is still called, even though the Shelf is not fully constructed. The code in shelve.Shelf does not check for this possibility, and therefor triggers an AttributeError. Here is an example script which should reproduce the error. ===Begin test.py====l import shelve try: shelf = shelve.open('non-existant-file', flag='r') except: pass ===End test.py===== For me, the above script produces the message: Exception exceptions.AttributeError: "DbfilenameShelf instance has no attribute 'writeback'" in ignored I can reproduce this using either Python 2.4.1 or 2.3.5. I took a quick look at the current CVS version of shelve.py, and it appears to suffer the same problem.
msg26743 - (view)	Author: Georg Brandl (georg.brandl) *	Date: 2006-01-20 22:10
Logged In: YES user_id=1188172 Is this a bug? As exceptions in __del__ are ignored, this should do no harm.
msg26744 - (view)	Author: Geoffrey T. Dairiki (dairiki)	Date: 2006-01-25 15:39
Logged In: YES user_id=45814 Exceptions thrown in __del__ are not quite complete ignored, since the fact that they are being "ignored" is reported on sys.stderr. The bug in question results in spurious, confusing messages being issued to sys.stderr. I say it is a bug.
msg26745 - (view)	Author: Georg Brandl (georg.brandl) *	Date: 2006-06-14 06:09
Logged In: YES user_id=849994 Fixed in rev. 46946, 46947 (2.4).