Guide to install Python correctly on MacOS

22 May 2018

I work quite a bit with python, it’s my go to language whenever I need to a quick script to get something done.

In this guide, I will talk about:

• manage python with homebrew
• virtualenv
• virtualenv wrappper

What’s Homebrew

Homebrew (link) is a package manager for MacOS. If you are familiar with linux, it is the equivilant of apt-get. I use homebrew to install and update most of my development tools.

Installing python with Homebrew

Most modern system nowadays should have python installed but usually those python are never updated and are often outdated. You can check its version by typing python --version in your terminal.

On the MacOS, the default python used is installed by Apple. This version of python is severly outdated (In fact, Apple still uses python 2 which is deprecated now.)

To begin, you should have homebrew installed. (link to install here) If you have not done so, go to the link provided.

Next, simply type brew install python to install brew’s version of python. As of right now, brew automaticlly installs python 3 to the folder /usr/local/bin. (Default python is at /usr/bin).

To update python, just type brew update and brew upgrade. The update will download the new versions of its dependencies and the upgrade will actually upgrade to the new versions.

Virtualenv

Virtualenv allows you to have multiple different development environments. What this means is that I can have a project that uses python 2.7 while another uses python 3.2. Or I might want the old selenium library for legacy code while in another project I will want the newest one. Virtualenv, or virtual environments, allow you to setup a temporary development environment for each python project.

To install, type pip install virtualenv virtualenvwrapper.

When you want to create a new virtualenv just type mkvirtualenv <env name> to initialize a new virtualenv. To activate it, type workon <env name>. To disable it, type deactivate.

So there you go, I’ll update this later to talk more about the virtualenv.

WIP.