Python Tenacity 日志重试异常

Question

我正在使用该tenacity包重试某个功能。我的重试装饰器如下所示：

@retry(wait=wait_exponential(multiplier=1/(2**5), max=60), after=after_log(logger, logging.INFO))

在异常情况下，我收到如下日志消息：

INFO:mymodule:Finished call to 'mymodule.MyClass.myfunction' after 0.001(s), this was the 1st time calling it.

除了已经记录的内容之外，我还想记录实际的异常（1 行格式，最好不是堆栈跟踪）。凭着毅力能做到吗？或者我只需要捕获异常、打印并重新引发？

Answer 1

您可以设置before_sleep参数。该可调用函数接收exc_info您的代码抛出的异常。参考：https://tenacity.readthedocs.io/en/latest/api.html#module-tenacity.before_sleep

例子

import logging
from typing import Final

from tenacity import (
    after_log,
    before_sleep_log,
    retry,
    retry_if_exception_type,
    stop_after_attempt,
    wait_exponential,
)

logger: Final = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)


@retry(
    reraise=True,
    before_sleep=before_sleep_log(logger, logging.INFO),
    after=after_log(logger, logging.INFO),
    wait=wait_exponential(multiplier=1, min=1, max=8),
    retry=retry_if_exception_type(ZeroDivisionError),
    stop=stop_after_attempt(4),
)
def never_gonna_give_you_up() -> None:
    1 / 0


if __name__ == "__main__":
    never_gonna_give_you_up()

输出

INFO:__main__:Finished call to '__main__.never_gonna_give_you_up' after 0.000(s), this was the 1st time calling it.
INFO:__main__:Retrying __main__.never_gonna_give_you_up in 1.0 seconds as it raised ZeroDivisionError: division by zero.
INFO:__main__:Finished call to '__main__.never_gonna_give_you_up' after 1.015(s), this was the 2nd time calling it.
INFO:__main__:Retrying __main__.never_gonna_give_you_up in 2.0 seconds as it raised ZeroDivisionError: division by zero.
INFO:__main__:Finished call to '__main__.never_gonna_give_you_up' after 3.031(s), this was the 3rd time calling it.
INFO:__main__:Retrying __main__.never_gonna_give_you_up in 4.0 seconds as it raised ZeroDivisionError: division by zero.
INFO:__main__:Finished call to '__main__.never_gonna_give_you_up' after 7.031(s), this was the 4th time calling it.
Traceback (most recent call last):
  File "C:\***.py", line 33, in <module>
    never_gonna_give_you_up()
  File "C:\Users\***\lib\site-packages\tenacity\__init__.py", line 324, in wrapped_f
    return self(f, *args, **kw)
  File "C:\Users\***\lib\site-packages\tenacity\__init__.py", line 404, in __call__
    do = self.iter(retry_state=retry_state)
  File "C:\Users\***\lib\site-packages\tenacity\__init__.py", line 360, in iter
    raise retry_exc.reraise()
  File "C:\Users\***\lib\site-packages\tenacity\__init__.py", line 193, in reraise
    raise self.last_attempt.result()
  File "C:\Users\***\AppData\Local\Programs\Python\Python310\lib\concurrent\futures\_base.py", line 439, in result
    return self.__get_result()
  File "C:\Users\***\AppData\Local\Programs\Python\Python310\lib\concurrent\futures\_base.py", line 391, in __get_result
    raise self._exception
  File "C:\Users\***\lib\site-packages\tenacity\__init__.py", line 407, in __call__
    result = fn(*args, **kwargs)
  File "C:\***.py", line 29, in never_gonna_give_you_up
    1 / 0
ZeroDivisionError: division by zero

这些行由以下命令打印before_sleep_log：

Retrying __main__.never_gonna_give_you_up in 1.0 seconds as it raised ZeroDivisionError: division by zero.