[Python-Dev] Mutable exceptions? (was Re: PEP 293, Codec Error Handling Callbacks)

Guido van Rossum guido@python.org
Thu, 15 Aug 2002 14:15:51 -0400

> This looks like an issue that potentially deserves more community
> feedback, so I'm ripping it out and starting a new thread: should
> exception objects be treated as mutable as exceptions get caught and
> re-raised?

(A new thread in python-dev hardly counts as "community feedback".)

I'd say definitely.  Code like this looks reasonable to me:

  def some_function(arg):
    except SomeExpectedExceptionClass, obj:

Then some outer piece of code catches exceptions and produces a
traceback augmented by information added by various calls to

--Guido van Rossum (home page: http://www.python.org/~guido/)