[Python-3000] Exception re-raising woes

[Mark Hammond]

> >> This would render the following code illegal:
> >>
> >> def f():
> >>   try: 1/0
> >>   except: pass
> >>   raise
> >
> > But you may want to use bare raise in a function called from an
> exception
> > handler, e.g.:
> >
> > def handle_exception():
> >    if user() == "Albert":
> >        # Albert likes his exceptions uncooked
> >        raise
> >    else:
> >        logging.exception("an exception occurred")
> >
> > def f():
> >    try:
> >        raise KeyError
> >    except:
> >        handle_exception()
> 
> This can be rewritten to use sys.exc_info(), ie:
> 
> def handle_exception():
>     if user() == "Albert":
>         # Albert likes his exceptions uncooked
>         raise sys.exc_info()[1]
>     else:
>         logging.exception("an exception occurred")

In both Python 2.x and 3 (a few months old build of Py3k though), the
traceback isn't the same.  For Python 2.0 you could write it like:

def handle_exception():
...
    raise sys.exc_info()[0], sys.exc_info()[1], sys.exc_info()[2]

Its not clear how that would be spelt in py3k though (and from what I can
see, sys.exc_info() itself has an uncertain future in py3k).

Cheers,

Mark