Asyncio does not handle nested KeyboardInterrupt correctly

[user202729]

Bug report

Bug description:

Consider this code

import sys
import logging
import asyncio
import signal
from time import*

logger = logging.getLogger(__name__)

logging.basicConfig(level=logging.INFO)

async def f():
 if 1:
 main_task = asyncio.current_task()
 def on_sigint() -> None:
 logger.error("Received SIGINT")
 main_task.cancel(KeyboardInterrupt)
 asyncio.get_running_loop().add_signal_handler(signal.SIGINT, on_sigint)
 try:
 while True:
 await asyncio.sleep(0.1)
 print("*")
 except asyncio.CancelledError as e:
 print(e)
 try:
 while True:
 await asyncio.sleep(0.1)
 print("#")
 except asyncio.CancelledError:
 try:
 while True:
 await asyncio.sleep(0.1)
 print("!")
 except asyncio.CancelledError:
 while True:
 await asyncio.sleep(0.1)
 print("@")

asyncio.run(f())

Intention: each time I press Ctrl-C, it repeatedly print *, #, !, @ respectively.

As is, it does do that correctly.

However, if I don't manually add the SIGINT signal handler, it will print *, {first Ctrl-C} #, {second Ctrl-C} !, {third Ctrl-C} then forcefully stop.

I don't think this behavior is desirable. Or at least it probably shouldn't log a scary error Task was destroyed but it is pending!?

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Linked PRs

• gh-146194: Fix nested KeyboardInterrupt handling in asyncio #146203

[picnixz]

@okiemute04 Please avoid using LLM for generating answers and do not claim that an issue is good to work on unless it has been triaged. This is the role of triagers and core devs.

cc @kumaraditya303

[kumaraditya303]

This is not a bug. By default if you press CTRL+C twice then you would break out of the loop with asyncio runner. This is a long standing behavior and should not be changed.