失败而不是打印 "Exception ignored in: <coroutine..."

Question

当明确告诉 Python 将 RuntimeWarning 视为异常时，Warning 成功变为 Exception。但是现在我得到一个 Exception ignored，程序仍然没有在它应该失败的地方失败。最小可重现示例：

import asyncio
import warnings

async def main():
    asyncio.sleep(1)
    print("I don't want this printed.")

warnings.filterwarnings("error", category=RuntimeWarning)
asyncio.run(main())

Exception ignored in: <coroutine object sleep at 0x7f1e4f3d1b40>
Traceback (most recent call last):
File "/home/teresaejunior/.asdf/installs/python/3.9.2/lib/python3.9/warnings.py", line 506, in _warn_unawaited_coroutine
    warn(msg, category=RuntimeWarning, stacklevel=2, source=coro)
RuntimeWarning: coroutine 'sleep' was never awaited
I don't want this printed.

如何阻止 Python 忽略 warnings 模块引发的异常？

Answer 1

How can I stop Python from ignoring this exception?

遗憾的是，我不认为你可以，至少不能以明显的方式。问题是这个警告是在协程对象被销毁时打印的，这是 Python 可以确定你永远不会等待协程的最早时间点。

无法从析构函数中引发异常，因为析构函数在垃圾收集期间和其他敏感时间运行。所以当 Python 当时检测到异常时，它只是忽略它，正如消息所说。

失败而不是打印 "Exception ignored in: <coroutine..."

Fail instead of printing "Exception ignored in: <coroutine..."

python

asynchronous

async-await

python-asyncio