Example exception handler; prints a warning to stderr.

    tries_remaining: The number of tries remaining.
    exception: The exception instance which was raised.

def example_exc_handler(tries_remaining, exception, delay):
    """Example exception handler; prints a warning to stderr.

    tries_remaining: The number of tries remaining.
    exception: The exception instance which was raised.
    """
    print >> sys.stderr, "Caught '%s', %d tries remaining, sleeping for %s seconds" % (
        exception, tries_remaining, delay)