Bugs item #942706, was opened at 2004-04-26 23:39
Message generated for change (Comment added) made by gbrandl
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=942706&group_id=5470
Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Python Interpreter Core
Group: Python 2.3
>Status: Closed
>Resolution: Works For Me
Priority: 5
Submitted By: has (hhas)
Assigned to: Nobody/Anonymous (nobody)
Summary: Python crash on __init__/__getattr__/__setattr__ interaction
Initial Comment:
The following code causes [Mac]Python 2.3 process to crash
(Bad!) rather than raise an error (good) when creating a new
instance of Foo:
class Foo:
def __init__(self):
self.x = 1
def __getattr__(self, name):
if self.x:
pass # etc...
def __setattr__(self, name, val):
if self.x:
pass # etc...
(See <http://freespace.virgin.net/hamish.sanderson/
HTMLTemplate-0.4.0.tar.gz> for a working example plus general
solution to the referencing-instance-var-before-it's-created
paradox that threw up this bug in the first place.)
----------------------------------------------------------------------
>Comment By: Georg Brandl (gbrandl)
Date: 2006-02-21 16:03
Message:
Logged In: YES
user_id=849994
Closing then.
----------------------------------------------------------------------
Comment By: has (hhas)
Date: 2006-02-20 23:48
Message:
Logged In: YES
user_id=996627
Original test used a framework build of Python 2.3.x on Mac OS X 10.2.8; I've
upgraded to OS 10.4.4 since and can't reproduce the problem on that - I get the
standard recursion error as expected. I've no further insights into why I had
problems originally and no-one else seems to have reproduced it, so probably
best just to close it. Sorry not to be of more help.
----------------------------------------------------------------------
Comment By: Georg Brandl (gbrandl)
Date: 2006-02-20 21:54
Message:
Logged In: YES
user_id=849994
OP: Any further insights?
----------------------------------------------------------------------
Comment By: Georg Brandl (birkenfeld)
Date: 2006-01-10 21:56
Message:
Logged In: YES
user_id=1188172
To the OP: Is there still a crash with newest Python 2.4?
----------------------------------------------------------------------
Comment By: Walter Dörwald (doerwalter)
Date: 2004-06-02 19:17
Message:
Logged In: YES
user_id=89016
Assigning to self.x in __init__() calls __setattr__(), which
checks self.x, which calls __getattr__() which checks self.x,
which leads to endless recursion. This usually leads to
a "RuntimeError: maximum recursion depth exceeded". In what
way does Python 2.3 crash?
To avoid the recursion access the instance dictionary directly:
class Foo:
def __init__(self):
self.x = 1
def __getattr__(self, name):
if "x" in self.__dict__ and self.__dict__["x"]:
pass # etc...
def __setattr__(self, name, val):
if self.x:
pass # etc...
----------------------------------------------------------------------
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=942706&group_id=5470
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
