Message 68582 - Python tracker

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Author	pitrou
Recipients	Rhamphoryncus, benjamin.peterson, gvanrossum, pitrou
Date	2008-06-22.20:56:06
SpamBayes Score	0.2327986
Marked as misclassified	No
Message-id	<1214168164.6056.94.camel@fsol>
In-reply-to	<[email protected]>

Content
Le dimanche 22 juin 2008 à 20:40 +0000, Adam Olsen a écrit : > > How do you duplicate an instance of an user-defined exception? Using > an > > equivalent of copy.deepcopy()? It will probably end up much more > > expensive than the above-mentioned O(n) search. > > Passing in e.args is probably sufficient. I think it's very optimistic :-) Some exception objects can hold dynamic state which is simply not stored in the "args" tuple. See Twisted's Failure objects for an extreme example: http://twistedmatrix.com/trac/browser/trunk/twisted/python/failure.py (yes, it is used an an exception: see "raise self" in the trap() method) > Can be, or will be? Only the most common behaviour needs to be optimized. Well, the "most common behaviour" is a very short context chain, which is already optimized by my reference-avoidance proposal...

Le dimanche 22 juin 2008 à 20:40 +0000, Adam Olsen a écrit :
> > How do you duplicate an instance of an user-defined exception? Using
> an
> > equivalent of copy.deepcopy()? It will probably end up much more
> > expensive than the above-mentioned O(n) search.
> 
> Passing in e.args is probably sufficient.

I think it's very optimistic :-) Some exception objects can hold dynamic
state which is simply not stored in the "args" tuple. See Twisted's
Failure objects for an extreme example:
http://twistedmatrix.com/trac/browser/trunk/twisted/python/failure.py

(yes, it is used an an exception: see "raise self" in the trap() method)

> Can be, or will be?  Only the most common behaviour needs to be optimized.

Well, the "most common behaviour" is a very short context chain, which
is already optimized by my reference-avoidance proposal...

History
Date	User	Action	Args
2008-06-22 20:56:09	pitrou	set	spambayes_score: 0.232799 -> 0.2327986 recipients: + pitrou, gvanrossum, Rhamphoryncus, benjamin.peterson
2008-06-22 20:56:07	pitrou	link	issue3112 messages
2008-06-22 20:56:06	pitrou	create