These instructions are for Mac OS:
First install homebrew. Never use sudo for brew.
$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" $ which brew /usr/local/bin/brew
Install Python3. The installation comes with pip3.
$ brew install python3 $ which pip3 /usr/local/bin/pip3
Install cx_Oracle, the library that allows python3 to communicate with Oracle database.