Jupyter Notebook 无法在 Windows 10 中使用 python 3.8 启动 [重复]

Question

这里是使用 python 3.8 版启动 jupyter notebook 时的详细错误

  File "c:\users\kokat\appdata\local\programs\python\python38\lib\runpy.py", line 192, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\kokat\AppData\Local\Programs\Python\Python38\Scripts\jupyter-notebook.EXE\__main__.py", line 9, in <module>
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\jupyter_core\application.py", line 266, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\traitlets\config\application.py", line 657, in launch_instance
    app.initialize(argv)
  File "<c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\decorator.py:decorator-gen-7>", line 2, in initialize
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\traitlets\config\application.py", line 87, in catch_config_error
    return method(app, *args, **kwargs)
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\notebook\notebookapp.py", line 1628, in initialize
    self.init_webapp()
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\notebook\notebookapp.py", line 1407, in init_webapp
    self.http_server.listen(port, self.ip)
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\tornado\tcpserver.py", line 144, in listen
    self.add_sockets(sockets)
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\tornado\tcpserver.py", line 157, in add_sockets
    self._handlers[sock.fileno()] = add_accept_handler(
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\tornado\netutil.py", line 268, in add_accept_handler
    io_loop.add_handler(sock, accept_handler, IOLoop.READ)
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\site-packages\tornado\platform\asyncio.py", line 79, in add_handler
    self.asyncio_loop.add_reader(
  File "c:\users\kokat\appdata\local\programs\python\python38\lib\asyncio\events.py", line 498, in add_reader
    raise NotImplementedError
NotImplementedError

任何帮助将不胜感激。

Answer 1

Jupyter notebook 作为tornado web 服务器运行。您的浏览器通过套接字连接到此龙卷风服务器。

socket 的 I/O 由 tornado 的 asyncio 处理，它依赖于 python 运行时本机 asyncio 模块的 add_reader 实现。正如asyncio 的documentation 中所指出的，这种方法仅支持Windows SelectorEventLoop，因此请确保在python 安装中使用这种事件循环。要找出正在使用的事件循环实现，您可以在 python shell 中运行以下命令：

import asyncio
print(asyncio.get_event_loop().__class__)
# Output: <class 'asyncio.windows_events._WindowsSelectorEventLoop'>

关于允许用户在 jupyter 的配置文件中更改 asyncio 的 EventLoopPolicy 正在进行中的 discussion。

Answer 2

按照this thread 中的一个cmets，我通过以下方式解决了问题：

1. 找到并打开 asyncio.py 文件。就我而言，它位于C:\Users\[USERNAME]\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\tornado\platform\
2. 在import asyncio 行之后添加以下内容：

from sys import platform 
if platform == "win32":               
    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy()) # python-3.8.0a4

这将强制在 Windows 上使用 SelectorEventLoop。