Installing the IPython kernel

Kernels for different Python versions

If you want a kernel for a different version of Python than the one Jupyter is running on, install ipykernel using that Python and register it:

/path/to/python -m pip install ipykernel
/path/to/python -m ipykernel install --user

Or using conda, create an environment with the desired Python version:

conda create -n py312 python=3.12 ipykernel
conda activate py312
python -m ipykernel install --user --name py312 --display-name "Python 3.12"

The last command installs a kernel spec file for the current python installation. Kernel spec files are JSON files, which can be viewed and changed with a normal text editor.

Kernels for different environments

If you want to have multiple IPython kernels for different virtualenvs or conda environments, you will need to specify unique names for the kernelspecs.

Make sure you have ipykernel installed in your environment. If you are using pip to install ipykernel in a conda env, make sure pip is installed:

conda activate myenv
conda install pip
conda install ipykernel # or pip install ipykernel

For example, using conda environments, install a Python (myenv) Kernel in a first environment:

conda activate myenv
python -m ipykernel install --user --name myenv --display-name "Python (myenv)"

And in a second environment, after making sure ipykernel is installed in it:

conda activate other-env
python -m ipykernel install --user --name other-env --display-name "Python (other-env)"

The --name value is used by Jupyter internally. These commands will overwrite any existing kernel with the same name. --display-name is what you see in the notebook menus.

Using virtualenv or conda envs, you can make your IPython kernel in one env available to Jupyter in a different env. To do so, run ipykernel install from the kernel’s env, with –prefix pointing to the Jupyter env:

/path/to/kernel/env/bin/python -m ipykernel install --prefix=/path/to/jupyter/env --name 'python-my-env'

Note that this command will create a new configuration for the kernel in one of the preferred location (see jupyter --paths command for more details):

system-wide (e.g. /usr/local/share),
in Jupyter’s env (sys.prefix/share),
per-user (~/.local/share or ~/Library/share)

If you want to edit the kernelspec before installing it, you can do so in two steps. First, ask IPython to write its spec to a temporary location:

ipython kernel install --prefix /tmp

edit the files in /tmp/share/jupyter/kernels/python3 to your liking, then when you are ready, tell Jupyter to install it (this will copy the files into a place Jupyter will look):

jupyter kernelspec install /tmp/share/jupyter/kernels/python3