Installing Homebrew, Python3, and Jupyter Notebook on MacOSX

Open your terminal and run the following set of commands

Step 1) Install X-Code

xcode-select --install

Step 2) Install Homebrew for MacOSX

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Step 3) Confirm homebrew was successfully installed

brew doctor

Step 4) Install Python 3

brew install python3
brew postinstall python3

Step 5) Install Jupyter Notebook

pip3 install jupyter

Step 6) Install Jupyter Lab

pip3 install jupyterlab

Step 7) Launch jupyter notebook (lab edition)

jupyter lab

Additional sources

Installing Homebrew Package Manager on Mac
Installing Python3 on Mac
Installing Jupyter on Mac