[Python-Dev] PEP 344: Exception Chaining and Embedded Tracebacks

[Aahz]

On Mon, May 16, 2005, Ka-Ping Yee wrote:
>
> This PEP is a concrete proposal for exception chaining, to follow
> up on its mention here on Python-Dev last week as well as earlier
> discussions in the past year or two.
> 
>     http://www.python.org/peps/pep-0344.html
> 
> I've tried to summarize the applications for chaining mentioned in
> these discussions, survey what's available in other languages, and
> come up with a precise specification.
> 
> PEP 344 proposes three standard attributes on traceback objects:
> 
>     __context__ for implicit chaining (an unexpected exception
>         occurred during 'except' or 'finally' processing)
> 
>     __cause__ for explicit chaining (intentional translation or
>         augmenting of exceptions, set by "raise EXC from CAUSE")
> 
>     __traceback__ to point to the traceback
> 
> Hope this is useful.  I'd like your feedback.  Thanks!

I'll comment here in hopes of staving off responses from multiple
people: I don't think these should be double-underscore attributes.  The
currently undocumented ``args`` attribute isn't double-underscore, and I
think that's precedent to be followed.
-- 
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

"And if that makes me an elitist...I couldn't be happier."  --JMS