Recently, jupyter note book always has various problems, it is simple to reinstall it directly.
1. Completely uninstall jupyter note book
Note:
Jupyter cannot be uninstalled using pip uninstall jupyter.
You need to uninstall jupyter using the following command:
pip install pip-autoremove
pip-autoremove jupyter -y
2. Reinstall jupyter notebook
pip3 install --upgrade --force-reinstall --no-cache-dir jupyter
Reinstall everything in PyPi and
you can use jupyter notebook normally