来自 Future 的简单 Python 日志记录异常

Question

这应该是一个非常简单的问题，但是在谷歌搜索、阅读文档和其他几个 SO 线程之后，我没有看到答案：如何使用 Python 标准日志记录异常？一个小问题是我从未来得到了例外。我自己不是在编写except 异常处理程序。理想情况下，我会得到异常消息、堆栈跟踪、发送的额外消息以及异常类型。这是一个显示我的问题的简单程序：

import logging
from concurrent.futures import ThreadPoolExecutor

logger = logging.getLogger(__name__)


def test_f(a, b=-99, c=50):
    logger.info("test_f a={} b={} c={}".format(a, b, c))


def future_callback_error_logger(future):
    e = future.exception()
    if e is not None:
        # This log statement does not seem to do what I want.
        # It logs "Executor Exception" with no information about the exception.
        # I would like to see the exception type, message, and stack trace.
        logger.error("Executor Exception", exc_info=e)


def submit_with_log_on_error(executor, func, *args, **kwargs):
    future = executor.submit(func, *args, **kwargs)
    future.add_done_callback(future_callback_error_logger)


if __name__ == "__main__":
    logging.basicConfig(level="DEBUG")

    logger.info("start")
    executor = ThreadPoolExecutor(max_workers=5)

    # This will work.
    submit_with_log_on_error(executor, test_f, 10, c=20)
    # This will intentionally trigger an error due to too many arguments.
    # I would like that error to be properly logged.
    submit_with_log_on_error(executor, test_f, 10, 20, 30, 40)
    # This will work.
    submit_with_log_on_error(executor, test_f, 50, c=60)

    executor.shutdown(True)
    logger.info("shutdown")

Answer 1

要使用logger.exception 并获取回溯等，您需要位于一个 except 块内。不要检查future.exception()，它返回异常（如果有），而是使用future.result()，它引发异常（如果有）。

所以，try 这个代替（不是双关语）：

def future_callback_error_logger(future):
    try:
        future.result()
    except Exception:
        logger.exception("Executor Exception")