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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Doubt in `spinner_async.py` example","articleBody":"Hi Luciano,\r\n\r\nI am playing a bit with the [`spinner_async.py`](https://github.com/fluentpython/example-code-2e/blob/master/19-concurrency/spinner_async.py) example, and I am wondering why the execution finishes normally when I comment the `spinner.cancel()` line in the `supervisor` function. I think the execution should stay in an infinite loop because I am not cancelling the coroutine and, therefore the `asyncio.CancelledError` exception is never raised.\r\n\r\n```python3\r\nasync def supervisor() -\u003e int:  # \u003c3\u003e\r\n    spinner = asyncio.create_task(spin('thinking!'))  # \u003c4\u003e\r\n    print(f'spinner object: {spinner}')  # \u003c5\u003e\r\n    result = await slow()  # \u003c6\u003e\r\n    #spinner.cancel()  # \u003c------This is the only change \u003c7\u003e\r\n    return result\r\n```\r\n\r\nI am forgetting something?, any comments to help me to understand this scenario are welcome.","author":{"url":"https://github.com/CarMoreno","@type":"Person","name":"CarMoreno"},"datePublished":"2023-08-07T08:14:09.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/37/example-code-2e/issues/37"}