How do I add python3 kernel to jupyter (IPython)

Question

My Jupyter notebooks installed with python 2 kernel. I do not understand why. I might have messed something up when I did the install. I already have python 3 installed. How can I add it to Jupyter? Here's a screenshot of what the default Jupyter insalled with python3 -m install jupyter and opened in the browser with jupyter notebooklooks like:

Answer 1

Make sure you have ipykernel installed and use ipython kernel install to drop the kernelspec in the right location for python2. Then ipython3 kernel install for Python3. Now you should be able to chose between the 2 kernels regardless of whether you use jupyter notebook, ipython notebook or ipython3 notebook (the later two are deprecated).

Note that if you want to install for a specific Python executable you can use the following trick:

path/to/python -m ipykernel install <options>

This works when using environments (venv,conda,...) and the <options> let you name your kernel (see --help). So you can do

conda create -n py36-test python=3.6
source activate py36-test
python -m ipykernel install --name py36-test
source deactivate

And now you get a kernel named py36-test in your dropdown menus, along the other ones.

See Using both Python 2.x and Python 3.x in IPython Notebook which has more recent information.

Answer 2

When you use conda managing your python envs, follow these two steps:

1. activate py3 (on Windows or source activate py3 on Linux)
2. conda install notebook ipykernel or just use conda install jupyter

Answer 3

Following command works for me, on macOS Sierra(10.12.3)

python3 -m pip install ipykernel
python3 -m ipykernel install --user

check it with jupyter kernelspec list Available kernels: python3 /Users/admin/Library/Jupyter/kernels/python3 python2 /anaconda2/share/jupyter/kernels/python2

Answer 4

On Ubuntu 14.04 I had to use a combination of previous answers.

First, install pip3 apt-get install python-pip3

Then with pip3 install jupyter pip3 install jupyter

Then using ipython3 install the kernel ipython3 kernel install

Answer 5

The solution is well documented in the official docs: https://ipython.readthedocs.org/en/latest/install/kernel_install.html

I tried the first approach. Since I already had ipykernel installed, simply running python3 -m ipykernel install --user solved the problem.

Answer 6

I managed to install a Python3 kernel besides the Python2. Here is the way I did it:

• open a new notebook in Jupyter
• copy and run the two cells here: Enable-Python-3-kernel

The latest working link can be found here.

The actual code is:

! mkdir -p ~/.ipython/kernels/python3
%%file ~/.ipython/kernels/python3/kernel.json

{
 "display_name": "IPython (Python 3)", 
 "language": "python", 
 "argv": [
  "python3", 
  "-c", "from IPython.kernel.zmq.kernelapp import main; main()", 
  "-f", "{connection_file}"
 ], 
 "codemirror_mode": {
  "version": 2, 
  "name": "ipython"
 }
}