When you start a notebook after installing a new environment, sometimes you will not find your environment-kernel in the dropdown from the notebook.
To fix this, install ipykernel on to your desired environment. Here, we install it into
source activate new_env pip install ipykernel
After installing ipykernel, run the command below. This will name the python interpreter in
new_env as “name_new_env” and can be found in the drop down for kernels list.
python -m ipykernel install --user --name new_env --display-name "name_new_env"