1、通过语言特性实现:
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:
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:
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