retry 0.9.2

重试decorator

defretry(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.
    """

各种重试逻辑可以通过参数的组合来实现。

fromretryimportretry

@retry()defmake_trouble():'''Retry until succeed'''

@retry(ZeroDivisionError,tries=3,delay=2)defmake_trouble():'''Retry on ZeroDivisionError, raise error after 3 attempts, sleep 2 seconds between attempts.'''

@retry((ValueError,TypeError),delay=1,backoff=2)defmake_trouble():'''Retry on ValueError or TypeError, sleep 1, 2, 4, 8, ... seconds between attempts.'''

@retry((ValueError,TypeError),delay=1,backoff=2,max_delay=4)defmake_trouble():'''Retry on ValueError or TypeError, sleep 1, 2, 4, 4, ... seconds between attempts.'''

@retry(ValueError,delay=1,jitter=1)defmake_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__':importlogginglogging.basicConfig()make_trouble()

重试呼叫

defretry_call(f,fargs=None,fkwargs=None,exceptions=Exception,tries=-1,delay=0,max_delay=None,backoff=1,jitter=0,logger=logging_logger):"""
    Calls a function and re-executes it if it failed.

    :param f: the function to execute.
    :param fargs: the positional arguments of the function to execute.
    :param fkwargs: the named arguments of the function to execute.
    :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.
    :returns: the result of the f function.
    """

这与decorator非常相似，只是它将函数及其参数作为参数。它背后的用例是能够动态地调整重试参数。

importrequestsfromretry.apiimportretry_calldefmake_trouble(service,info=None):ifnotinfo:info=''r=requests.get(service+info)returnr.textdefwhat_is_my_ip(approach=None):ifapproach=="optimistic":tries=1elifapproach=="conservative":tries=3else:# skepticaltries=-1result=retry_call(make_trouble,fargs=["http://ipinfo.io/"],fkwargs={"info":"ip"},tries=tries)print(result)what_is_my_ip("conservative")