registering kernels in ipython/jupyter notebook - kernel.json

Question

With the latest version of IPython, kernels can be registered by placing a kernel.json file in ~/.ipython/kernels/<kernel-name>/.

I am currently trying to add a julia and a R kernel and I am wondering who is responsible for creating and maintaining those kernel.json files.

Currently, I googled and created following kernel.json for julia by hand:

{
 "display_name": "Julia",
 "language": "julia",
 "argv": [
    "julia",
    "-i",
    "-F",
    "/User/<user>/.julia/v0.3/IJulia/src/kernel.jl",
    "{connection_file}"
 ],
 "codemirror_mode":"julia"
}

While this works, due the hardcoded path to kernel.jl I will have to adapt kernel.json for every major julia upgrade.

Do I have to take care of creating and maintaining these files? Or are they part of the kernel implementations or other third party packages?

Answer 1

Usually people create symbolic links to avoid depending on specific versions.

ln -s ~/.julia/v0.3 ~/.julia/latest

then you could use latest instead of v0.3 in kernel.json.

When you change versions you will only have to change the symbolic link.