Jupyterlab: How to remove/hide default "Python 3" Kernel?

user_1474073 0
Viewed 1204

I am running a custom-configured Jupyterlab installation for our company. It is wired to Livy and Spark to provide PySpark and Spark kernels, which works fine.

However, there is still the default Python 3 Kernel I want to remove: Kernels

When dropping to a console into the pod and doing a jupyter kernelspec list, I get, as expected:

Available kernels:
  pysparkkernel    /usr/local/share/jupyter/kernels/pysparkkernel
  python3          /usr/local/share/jupyter/kernels/python3
  sparkkernel      /usr/local/share/jupyter/kernels/sparkkernel

When I jupyter kernelspec remove python3, and reload Jupyterlab, the Python 3 Kernel is still there, and it reappears in the list:

Available kernels:
  python3          /usr/local/lib/python3.8/dist-packages/ipykernel/resources
  pysparkkernel    /usr/local/share/jupyter/kernels/pysparkkernel
  sparkkernel      /usr/local/share/jupyter/kernels/sparkkernel

Even when I delete this /usr/local/lib/python3.8/dist-packages/ipykernel/resources dir the kernel doesn't disappear.

Is it even possible to disable this default kernel or do I have to live with it?

Workaround

I got what I wanted by copying everything from the pysparkkernel into the python3 dir and removing the pysparkkernel, effectively making Jupyterlab think that the PySpark kernel is the default one.

While this works, I am still interested if this is the only way.

jupyter-lab jupyter-notebook
1 Answers

In addition to removing the kernel spec you need to turn off ensure_native_kernel option which makes sure that the default kernel is always included by adding:

c.KernelSpecManager.ensure_native_kernel = False

to your configuration file. You can set this via command line too:

jupyter lab --KernelSpecManager.ensure_native_kernel=False

as explained in https://github.com/jupyter/notebook/issues/3674

Note: if you are using JupyterLab 3.x with jupyter_server, the configuration is now stored in jupyter_server_config.py rather than jupyter_notebook_config.py as explained in the migration guide.

user_66469120
Related