Storing tracebacks

[kyosohma at gmail.com]

On May 28, 10:46 pm, George Sakkis <george.sak... at gmail.com> wrote:
> I'm reading the docs on sys.exc_info() but I can't tell for sure
> whether I'm using it safely to get a snapshot of an exception and
> reraise it later. The use case is a class which acts like a deferred
> callable, a callable that will be called at some point in the future
> (possibly in a different thread) and whose result or raised exception
> is to be stored as an attribute. This will be available by calling the
> result() method, which returns the original result or reraises the
> exception:
>
> class JobRequest(object):
>
>     def __init__(self, *args, **kwds):
>         self.args = args
>         self.kwds = kwds
>         self._exc_info = None
>
>     def __call__(self):
>         raise NotImplementedError('Abstract method')
>
>     def process(self):
>         try:
>             self._result = self(*self.args, **self.kwds)
>         except:
>             self._exc_info = sys.exc_info()
>         else:
>             self._exc_info = None
>
>     def result(self):
>         if self._exc_info is not None:
>             type,exception,traceback = self._exc_info
>             raise type,exception,traceback
>         try: return self._result
>         except AttributeError:
>             raise UnprocessedRequestError()
>
> class UnprocessedRequestError(RuntimeError):
>     pass
>
> So far it seems it works as expected but I'd like to know if this is
> error-prone and why.
>
> George

I don't know enough about this method of getting tracebacks, but why
wouldn't the traceback module work for you? It sounds like it uses the
sys.exc_info() method you refer to.

http://python.active-venture.com/lib/module-traceback.html

Mike