I am using Ubuntu 16.04 lts. My default python binary is python2.7. When I am trying to install ipykernel for hydrogen in atom editor, with the following command
python -m pip install ipykernel
It is giving the following errors
ERROR: ipykernel requires Python version 3.4 or above.
I am trying to install ipykernel for python2. I have already installed python3.7. Also ipython and jupyter notebook is installed.
Starting with version 5.0 of the kernel, and version 6.0 of IPython, compatibility with Python 2 was dropped. As far as I know, the only solution is to install an earlier release.
In order to have Python 2.7 available in the Jupyter Notebook I installed IPython 5.7, and ipykernel 4.10. If you want to install earlier releases of IPython or ipykernel you can do the following:
pip uninstall ipython
python2 -m pip install ipython==5.7 --user
python2 -m pip install ipykernel==4.10 --user