[Python-ideas] try-else without except or finally

[Matt Joiner]

Hi Ideas,

I frequently find myself in the following situations:

1) I wish to do something if no exception is thrown, for instance:

        try:
            logger.debug('Fiber starting: %s', self)
            try:
                self._result = self._routine()
            finally:
                logger.debug('Fiber finished: %s', self)
        except:
            raise
        else:
            raise FiberExit(self)
        finally:
            self._finished.set()
            unregister_fiber(self)

Here it's sufficient that that if an exception is already present, I
don't need to raise another. The except clause is clearly pointless.
2) I'm experimenting with catching various exceptions and remove the
last except clause. I need to put a finally: pass; to avoid having to
restructure all my code, since this is currently the only way to
maintain the try-except-else-finally statement without catching dummy
exceptions.

I propose that the except clause be optional.

Cheers,
Matt