Installing Jupyter <jupyter:install>
The IPython kernel is the Python execution backend for Jupyter.
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.
If you're running Jupyter on Python 3, you can set up a Python 2 kernel after checking your version of pip is greater than 9.0:
python2 -m pip --version
Then install with :
python2 -m pip install ipykernel
python2 -m ipykernel install --user
Or using conda, create a Python 2 environment:
conda create -n ipykernel_py2 python=2 ipykernel
source activate ipykernel_py2 # On Windows, remove the word 'source'
python -m ipykernel install --user
Note
IPython 6.0 stopped support for Python 2, so installing IPython on Python 2 will give you an older version (5.x series).
If you're running Jupyter on Python 2 and want to set up a Python 3 kernel, follow the same steps, replacing 2
with 3
.
The last command installs a 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.
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:
bash
source 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:
bash
source 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:
bash
source 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:
bash
/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:
bash
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):
bash
jupyter kernelspec install /tmp/share/jupyter/kernels/python3