No module named ipykernel_launcher

[Jayfeath3r]

I just install the notebook on my Python 3.8.5 by "pip install notebook" however when I want to run code it always says " connection failed"

Here is my information on CMD
D:>jupyter notebook
[I 18:50:10.057 NotebookApp] The port 8888 is already in use, trying another port.
[I 18:50:10.753 NotebookApp] Serving notebooks from local directory: D:
[I 18:50:10.754 NotebookApp] Jupyter Notebook 6.1.4 is running at:
[I 18:50:10.755 NotebookApp] http://localhost:8889/?token=8ad122ee40323a890964325f6ca2e7d6928f4e0b9710cc19
[I 18:50:10.758 NotebookApp] or http://127.0.0.1:8889/?token=8ad122ee40323a890964325f6ca2e7d6928f4e0b9710cc19
[I 18:50:10.759 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[C 18:50:11.053 NotebookApp]

To access the notebook, open this file in a browser:
    file:///C:/Users/Owner/AppData/Roaming/jupyter/runtime/nbserver-13556-open.html
Or copy and paste one of these URLs:
    http://localhost:8889/?token=8ad122ee40323a890964325f6ca2e7d6928f4e0b9710cc19
 or http://127.0.0.1:8889/?token=8ad122ee40323a890964325f6ca2e7d6928f4e0b9710cc19

[I 18:50:24.358 NotebookApp] Kernel started: 7e1c8010-786d-4cc3-a72e-e0f08daa6cbc, name: python3
d:\python.exe: No module named ipykernel_launcher
[I 18:50:27.284 NotebookApp] KernelRestarter: restarting kernel (1/5), new random ports
d:\python.exe: No module named ipykernel_launcher
[I 18:50:30.309 NotebookApp] KernelRestarter: restarting kernel (2/5), new random ports
d:\python.exe: No module named ipykernel_launcher
[I 18:50:33.321 NotebookApp] KernelRestarter: restarting kernel (3/5), new random ports
d:\python.exe: No module named ipykernel_launcher
[I 18:50:36.343 NotebookApp] KernelRestarter: restarting kernel (4/5), new random ports
d:\python.exe: No module named ipykernel_launcher
[W 18:50:39.371 NotebookApp] KernelRestarter: restart failed
[W 18:50:39.371 NotebookApp] Kernel 7e1c8010-786d-4cc3-a72e-e0f08daa6cbc died, removing from map.
[W 18:51:24.430 NotebookApp] Timeout waiting for kernel_info reply from 7e1c8010-786d-4cc3-a72e-e0f08daa6cbc
[E 18:51:24.434 NotebookApp] Error opening stream: HTTP 404: Not Found (Kernel does not exist: 7e1c8010-786d-4cc3-a72e-e0f08daa6cbc)
[W 18:51:25.916 NotebookApp] 404 GET /api/kernels/7e1c8010-786d-4cc3-a72e-e0f08daa6cbc/channels?session_id=2ccd41e52bfe41e698f69921bd5b39eb (::1): Kernel does not exist: 7e1c8010-786d-4cc3-a72e-e0f08daa6cbc
[W 18:51:25.928 NotebookApp] 404 GET /api/kernels/7e1c8010-786d-4cc3-a72e-e0f08daa6cbc/channels?session_id=2ccd41e52bfe41e698f69921bd5b39eb (::1) 13.96ms referer=None
[W 18:51:28.917 NotebookApp] Replacing stale connection: 7e1c8010-786d-4cc3-a72e-e0f08daa6cbc:2ccd41e52bfe41e698f69921bd5b39eb

[web-sys1]

@Jayfeath3r Same problem, while have been trying to do in software application under pyinstaller too.

[kevin-bates]

Please locate the kernel.json file associated with the kernel you're trying to start by running jupyter kernelspec list and locating the kernel spec's directory. It strikes me as odd that you have python.exe at the root of your drive and perhaps it doesn't have the necessary information to locate other python modules like ipykernel_launcher. Once the kernel.json has been located, focus on the argv stanza.

This section of the docs may provide some additional tips.

[web-sys1]

@kevin-bates Yes, but there is a problem. Does Jupyter Notebook works perfectly -even converted to software- after the application is built to .exe under Pyinstaller? Maybe, waste time. Please help explain this situation. This issue #3246 was left unresolved.

[zwarshavsky]

I have just discovered the same issue while associating ipykernel with python 3.8. When I downgraded to Python 3.7, the issue was resolved. kernel.json was identical in both the 3.7 and 3.8 environments.

[kevin-bates]

This sounds like ipykernel (which provides ipykernel_launcher) wasn't properly installed. Try uninstalling/installing ipykernel in your 3.8 env.