如何修复 asyncio RuntimeError: This event loop is already running
问题
尝试使用 asyncio.run_until_complete() 运行 async def 函数时，例如
asyncio_example.py
import asyncio
asyncio.get_event_loop().run_until_complete(asyncio.sleep(1))你看到如下错误消息
asyncio_runtimeerror_example.txt
Cell In[3], line 15
12 raise
14 # Usage example:
---> 15 asyncio.get_event_loop().run_until_complete(asyncio.sleep(1))
File /usr/lib/python3.12/asyncio/base_events.py:663, in BaseEventLoop.run_until_complete(self, future)
652 """Run until the Future is done.
653
654 If the argument is a coroutine, it is wrapped in a Task.
(...)
660 Return the Future's result, or raise its exception.
661 """
662 self._check_closed()
--> 663 self._check_running()
665 new_task = not futures.isfuture(future)
666 future = tasks.ensure_future(future, loop=self)
File /usr/lib/python3.12/asyncio/base_events.py:622, in BaseEventLoop._check_running(self)
620 def _check_running(self):
621 if self.is_running():
--> 622 raise RuntimeError('This event loop is already running')
623 if events._get_running_loop() is not None:
624 raise RuntimeError(
625 'Cannot run the event loop while another loop is running')
RuntimeError: This event loop is already running解决方案
不要使用 loop.run_until_complete()，而是使用 asyncio.create_task() 运行协程：
asyncio_create_task.py
future = asyncio.get_event_loop().create_task(asyncio.sleep(1))可选地，你可以 await future 来等待协程完成：
asyncio_await_future.py
await future原因是 loop.run_until_complete() 用于同步代码，并且总是启动循环，因此如果循环已经在运行，它将失败。
通常，如果你从 Jupyter Notebook 等上下文运行代码，会出现此错误，因为 Jupyter 在内部启动了事件循环。如果你想在纯 Python 脚本等其他上下文中运行它，可能需要修改代码。
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