jupyter-client has to be installed but “jupyter kernelspec --version” exited with code 127

Question

I have already installed Jupyter notebook in my ubuntu 16.04 machine. In jupyter notebook there is by default python installed. Now I want to use R from jupyter notebook.

To do so I followed IRkernel installation link and run below commands:

install.packages('devtools')  devtools::install_github('IRkernel/IRkernel') 

But when I run IRkernel::installspec() command it shows below error:

jupyter-client has to be installed but “jupyter kernelspec --version” exited with code 127

I am now confused why this error occurs.

Answer 1

Running this command from RStudio will show this error. When you run this command from command line/ terminal then everything will be fine.

So just type R from your command line.

Then Run below commands:

install.packages('devtools')  devtools::install_github('IRkernel/IRkernel') 

IRkernel::installspec() 

Answer 2

1. If Anaconda is installed and the Jupyter-Notebook with it (should be the standard install), open up the Anaconda prompt, not the Windows command prompt or the Anaconda Navigator
2. Look up the executable of R (not Rgui or Rstudio), it should be somewhere like C:\Program Files\R\R-3.5.1\bin and remember the path typing cd C:\Program Files\R\R-3.5.1\bin and start R by typing R
3. typing IRkernel::installspec()
4. Now you can start an R kernel within Jupyter-Notebook