César Ferradas

Simplest way to make Python 3 the default on MacOS

18 February 2021

On a fresh MacOS install, Python defaults to version 2. Not ideal. Here I show you the quickest way to make the default Python 3.

1. Install Python 3

Do this via Homebrew, it’s the easiest.

brew install python@3

2. Add /usr/local/bin to your path

Homebrew will add python3 as an executable in /usr/local/bin. Add this directory to your path by running one of the following commands (depending on your shell preference):

echo 'export PATH=/usr/local/bin:$PATH' > ~/.bashrc
echo 'export PATH=/usr/local/bin:$PATH' > ~/.zshrc

Currently the python executable is actually Python 2. Try it:

$ which python && python --version
Python 2.X.X

We need to replace this executable with the python3 location, and this can be achieved by a symbolic link:

unlink /usr/local/bin/python
ln -s /usr/local/bin/python3 /usr/local/bin/python

Now restart your shell, and you should be good to go. Happy coding!

But what about pip?

If you’ve previously installed pip using an old version of Python, you should re-install it using the python executable which now points to python3.

You can do this with the following commands:

cd ~
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
which python && python --version # verify it's python 3
python get-pip.py

Then you can re-install any packages that you installed globally again.