Retries a function call on failure

retry.py

def retry(fn, times=1, delay=3, exc=[Exception]):
    """Calls :fn: and retries up to :times: times with a delay of :delay: while exceptions :exc: are raised"""
    import time
    for i in range(times):
        try:
            return fn()
        except tuple(exc), ex:
            if i < times:
                if delay is not None:
                    time.sleep(delay)
            else:
                raise ex