Kernel error: ipykernel NotImplementedError - python-3.x

Question

Error Message
Traceback (most recent call last):
File "G:\anaconda\envs\jup\lib\runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "G:\anaconda\envs\jup\lib\runpy.py", line 87, in _run_code
exec(code, run_globals)
File "C:\Users\sk_np\AppData\Roaming\Python\Python38\site-packages\ipykernel_launcher.py", line 16, in <module>
app.launch_new_instance()
File "G:\anaconda\envs\jup\lib\site-packages\traitlets\config\application.py", line 844, in launch_instance
app.initialize(argv)
File "G:\anaconda\envs\jup\lib\site-packages\traitlets\config\application.py", line 87, in inner
return method(app, *args, **kwargs)
File "C:\Users\sk_np\AppData\Roaming\Python\Python38\site-packages\ipykernel\kernelapp.py", line 448, in initialize self.init_sockets()
File "C:\Users\sk_np\AppData\Roaming\Python\Python38\site-packages\ipykernel\kernelapp.py", line 251, in init_sockets
self.init_iopub(context)
File "C:\Users\sk_np\AppData\Roaming\Python\Python38\site-packages\ipykernel\kernelapp.py", line 259, in init_iopub self.iopub_thread = IOPubThread(self.iopub_socket, pipe=True)
File "C:\Users\sk_np\AppData\Roaming\Python\Python38\site-packages\ipykernel\iostream.py", line 63, in __init__
self._setup_pipe_in()
File "C:\Users\sk_np\AppData\Roaming\Python\Python38\site-packages\ipykernel\iostream.py", line 126, in _setup_pipe_in
self._pipe_in = ZMQStream(pipe_in, self.io_loop)
File "G:\anaconda\envs\jup\lib\site-packages\zmq\eventloop\zmqstream.py", line 127, in __init__
self._init_io_state()
File "G:\anaconda\envs\jup\lib\site-packages\zmq\eventloop\zmqstream.py", line 552, in _init_io_state
self.io_loop.add_handler(self.socket, self._handle_events, self.io_loop.READ)
File "G:\anaconda\envs\jup\lib\site-packages\tornado\platform\asyncio.py", line 100, in add_handler
self.asyncio_loop.add_reader(fd, self._handle_events, fd, IOLoop.READ)
File "G:\anaconda\envs\jup\lib\asyncio\events.py", line 501, in add_reader
raise NotImplementedError
NotImplementedError
Conda Environment Info:
jupyter-client:7.1.2
jupyter_client:5.3.1
python:3.8.0
I tried This Github Issue and followed the steps of This stackoverflow post.
Reproduction steps:
Install anaconda3
create conda env with conda create -n env python=3.8
conda install -c anaconda jupyter
jupyter notebook

Answer 1

You have apparently anaconda installed, but also a seperate python installation, see how both C:\Users\sk_np\AppData\Roaming\Python\Python38 and G:\anaconda show up in your traceback. This is probably causing the issue due to inconsistencies in the packages. The simplest step, and the one that will save you a lot of headache in the future, would be to uninstall the python that you have at
C:\Users\sk_np\AppData\Roaming\Python\Python38
Additionally, run in your anaconda prompt (from which you tried to start jupyter)
jupyter kernelspec list
and then remove the kernel that is at C:\Users\sk_np\AppData\Roaming\Python\Python38 with
jupyter kernelspec remove <kernelName>