2.3.1. backoff¶

pip install backoff

backoff是Python中的一个重试库。它提供了一些装饰器和上下文管理器来实现重试逻辑。

主要功能¶

重试装饰器:可以将任意函数装饰为重试函数。可以指定重试次数、重试间隔、重试条件等:

from backoff import backoff

@backoff(tries=5, delay=1)
def unreliable_func():
    print('Trying...')
    raise ValueError

unreliable_func()
# Trying...
# Trying...
# Trying...
# Trying...
# Trying...

重试上下文管理器:可以将代码块设置为重试代码块:

from backoff import Backoff

with Backoff(tries=5, delay=1) as backoff:
    unreliable_func()

自定义重试条件:不仅可以指定重试次数,还可以传入一个函数来自定义重试条件:

from backoff import backoff

def should_retry(tries, exception):
    return tries < 5 and isinstance(exception, ValueError)

@backoff(should_retry)
def unreliable_func():
    print('Trying...')
    raise ValueError  # Retried 4 times

unreliable_func()