gistfile1.py

class ResourceExceptionHandler(object):
    """Context manager to handle Resource exceptions.

    Used when processing exceptions generated by API implementation
    methods (or their extensions).  Converts most exceptions to Fault
    exceptions, with the appropriate logging.
    """

    def __enter__(self):
        return None

    def __exit__(self, ex_type, ex_value, ex_traceback):
        if not ex_value:
            return True

        if isinstance(ex_value, exception.NotAuthorized):
            msg = unicode(ex_value)
            raise Fault(webob.exc.HTTPForbidden(explanation=msg))
        elif isinstance(ex_value, TypeError):
            LOG.exception(ex_value)
            raise Fault(webob.exc.HTTPBadRequest())
        elif isinstance(ex_value, Fault):
            LOG.info(_("Fault thrown: %s"), unicode(ex_value))
            raise ex_value
        elif isinstance(ex_value, webob.exc.HTTPException):
            LOG.info(_("HTTP exception thrown: %s"), unicode(ex_value))
            raise Fault(ex_value)

        # We didn't handle the exception
        return False