Python中的retry

1、通过语言特性实现：

?

1 2 3 4 5 6 7

for i in range(0,100):     while True:         try:             # do stuff         except SomeSpecificException:             continue         break

　

2、通过第三方库实现：

pip install retry

 

参数介绍：

?

1 2 3 4 5 6 7 8 9 10 11 12 13

def retry(exceptions=Exception, tries=-1, delay=0, max_delay=None, backoff=1, jitter=0, logger=logging_logger):     """Return a retry decorator.       :param exceptions: an exception or a tuple of exceptions to catch. default: Exception.     :param tries: the maximum number of attempts. default: -1 (infinite).     :param delay: initial delay between attempts. default: 0.     :param max_delay: the maximum value of delay. default: None (no limit).     :param backoff: multiplier applied to delay between attempts. default: 1 (no backoff).     :param jitter: extra seconds added to delay between attempts. default: 0.                    fixed if a number, random if a range tuple (min, max)     :param logger: logger.warning(fmt, error, delay) will be called on failed attempts.                    default: retry.logging_logger. if None, logging is disabled.     """

案例：

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

from retry import retry @retry() def make_trouble():     '''Retry until succeed''' @retry(ZeroDivisionError, tries=3, delay=2) def make_trouble():     '''Retry on ZeroDivisionError, raise error after 3 attempts, sleep 2 seconds between attempts.''' @retry((ValueError, TypeError), delay=1, backoff=2) def make_trouble():     '''Retry on ValueError or TypeError, sleep 1, 2, 4, 8, ... seconds between attempts.''' @retry((ValueError, TypeError), delay=1, backoff=2, max_delay=4) def make_trouble():     '''Retry on ValueError or TypeError, sleep 1, 2, 4, 4, ... seconds between attempts.''' @retry(ValueError, delay=1, jitter=1) def make_trouble():     '''Retry on ValueError, sleep 1, 2, 3, 4, ... seconds between attempts.''' # If you enable logging, you can get warnings like 'ValueError, retrying in # 1 seconds' if __name__ == '__main__':     import logging     logging.basicConfig()     make_trouble()

　　

参考：https://pypi.python.org/pypi/retry

https://stackoverflow.com/questions/2083987/how-to-retry-after-exception-in-python