The goal today is to make Jupyter aware of your pre-existing virtual environment by installing an IPython Kernel.
By running the terminal commands below you will be able to make Jupyter aware of the installation of Python in your virtual environment as well as all of the libraries you install through pip.
Activate Your Virtual Environment
Replace test_env with the name of the folder containing your virtual environment
source ~/virtualenvironment/test_env/bin/activate
Ensure Jupyter is Installed
pip install jupyter
Ensure ipykernel is Installed
pip install --user ipykernel
Install the IPython Kernel
Replace test_env with the name of the folder containing your virtual environment
python -m ipykernel install --user --name test_env
...Installed kernelspec test_env in /Users/pnelson/Library/Jupyter/kernels/test_env
Launch Jupyter Notebook
jupyter notebook
Change your Kernel
Inside Jupyter notebook on the toolbar, click Kernel > Change Kernel > your_kernel. You will now see the name of the active kernel at the top right.
List All Installed Kernels
ipython kernelspec list
Uninstall Kernels
ipython kernelspec remove <kernel_name>