René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Asyncio does not handle nested KeyboardInterrupt correctly","articleBody":"# Bug report\n\n### Bug description:\n\nConsider this code\n\n```python\nimport sys\nimport logging\nimport asyncio\nimport signal\nfrom time import*\n\nlogger = logging.getLogger(__name__)\n\nlogging.basicConfig(level=logging.INFO)\n\nasync def f():\n    if 1:\n        main_task = asyncio.current_task()\n        def on_sigint() -\u003e None:\n            logger.error(\"Received SIGINT\")\n            main_task.cancel(KeyboardInterrupt)\n        asyncio.get_running_loop().add_signal_handler(signal.SIGINT, on_sigint)\n    try:\n        while True:\n            await asyncio.sleep(0.1)\n            print(\"*\")\n    except asyncio.CancelledError as e:\n        print(e)\n        try:\n            while True:\n                await asyncio.sleep(0.1)\n                print(\"#\")\n        except asyncio.CancelledError:\n            try:\n                while True:\n                    await asyncio.sleep(0.1)\n                    print(\"!\")\n            except asyncio.CancelledError:\n                while True:\n                    await asyncio.sleep(0.1)\n                    print(\"@\")\n\nasyncio.run(f())\n```\n\nIntention: each time I press Ctrl-C, it repeatedly print `*`, `#`, `!`, `@` respectively.\n\nAs is, it does do that correctly.\n\nHowever, 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.\n\nI 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!`?\n\n### CPython versions tested on:\n\n3.13\n\n### Operating systems tested on:\n\nLinux\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-146203\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/user202729","@type":"Person","name":"user202729"},"datePublished":"2026-03-20T08:09:00.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/146194/cpython/issues/146194"}