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

[Ka-Ping Yee]

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!


-- Ping