Installing the IPython kernel

The Jupyter Notebook and other frontends automatically ensure that the IPython kernel is available. However, if you want to use a kernel with a different version of Python, or in a virtualenv or conda environment, you'll need to install that manually.

Using the Python version or environment for which you want to set up the kernel, run:

pip install ipykernel  # or: conda install ipykernel
python -m ipykernel install --user

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

See python -m ipykernel install --help for the list of installation options like naming the kernel, or non default install location.

Multiple IPython installations

If you want to have multiple IPython kernels for different environments, you will need to specify unique names for the kernelspecs, and you may also want to specify the display name of those kernels, so that you can clearly see which is which in the notebook menus:

source activate myenv
ipython kernel install --user --name myenv --display-name "Python (myenv)"
source activate other-env
ipython kernel install --user --name other-env --display-name "Python (other-env)"
source deactivate