How to add conda environment to jupyter lab

Question

i'm using jupyter lab, and i'm having trouble to add conda environment. The idea is to launch jupyter lab from my base environnment, and then to be able to choose my other conda envs as kernels.

I installed the package nb_conda_kernels which is supposed to do just that, but it's not working as I want. Indeed, let's assume I create a new conda environment, then i launch jupyter lab from base, I can't see the new environment as an available kernel.

I have found a "fix", which works everytime but is not convenient at all. If I install jupyter notebook in my new environment, then launch a jupyter notebook from this new environment, close it, go back to base environment, and then launch jupyter lab from base environment, my new environment is available as a kernel in jupyter lab.

If you know how to make it work without this "fix", i would be very grateful.

Answer 1

A solution using nb_conda_kernels. First, install it in your base environment :

(base)$ conda install -c conda-forge nb_conda_kernels

Then in order to get a kernel for the conda_env cenv :

$ conda activate cenv
(cenv)$ conda install ipykernel
(cenv)$ conda deactivate

You will get a new kernel named Python [conda env:cenv] in your next run of jupyter lab / jupyter notebook

Answer 2

Assuming your conda-env is named cenv, it is as simple as :

$ conda activate cenv
(cenv)$ conda install ipykernel
(cenv)$ ipython kernel install --user --name=<any_name_for_kernel>
(cenv($ conda deactivate

If you restart your jupyter notebook/lab you will be able to see the new kernel available.

PS: If you are using virtualenv etc. the above steps hold good.