Setting up a 2020 MacBook Pro for Python development

This is a note-to-self on setting up a 2020 13-inch MacBook Pro, largely for Python development. I imagine it will all be out-of-date by the time I set-up my next laptop but it’s possible it might be useful to someone in the meantime.

Applications

I don’t tend to use Homebrew Cask and suffer the indignity of either installing them from the App Store or downloading .dmg files and dragging them into /Applications.

From the App Store

There’s only a few of these that I use:

• Bear — my Bear notes are now my most valuable possession.
• Trello — by far my favourite workflow management app.
• Microsoft To Do — successor to Wunderlist.
• Slack
• Outline VPN client

Downloaded and dragged into /Applications

In rough order of usefulness:

• Alfred — install this Bear workflow and ensure it’s configured to search Chrome bookmarks.
• MacVim — install from Github to get the latest version.
• iTerm2
• Chrome
• 1Password (deliberately not from the App Store as such versions don’t support the QR code reader functionality)
• Spectacle
• Spotify
• Docker Desktop
• Postgres.app
• Zoom
• Dropbox
• Basecamp
• Vagrant

Homebrew formulae

Homebrew is best reserved for core system packages, where running the latest version is desirable. It’s less appropriate for project dependencies which require pinned versions — Docker is a better for that.

Start by installing Xcode’s command-line tools:

sudo xcode-select --install

then install Homebrew and a core set of formulae. The following is taken from a setup_new_macbook.sh script I use:

function install_homebrew_core_packages() {
    local packages=(
        bash
        bash-completion
        coreutils
        ctags
        fd
        fzf
        git
        graphviz
        htop
        httpie
        hub
        hugo
        imagemagick
        jq
        pgbadger
        pv
        rename
        ripgrep
        terminal_notifier
        the_silver_searcher
    )
    brew install ${packages[@]}
}

plus some packages that require a separate tap:

function install_homebrew_tap_packages() {
    brew tap heroku/brew && brew install heroku

    brew tap homebrew/cask-fonts
    local fonts=(
        font-inconsolata
        font-clear-sans
        font-source-code-pro
        font-anonymous-pro
    )
    brew cask install ${fonts[@]}
}

Ensure your ~/.bash_profile has shell completion enabled for Homebrew-installs packages by following the documented instructions.

MacOS configuration

It’s too dull to go through everything. Here are few notable changes:

Non-breaking spaces

Unbind ⌥ + SPACE from inserting a non-breaking space by setting the contents of ~/Library/KeyBindings/DefaultKeyBinding.dict to:

{
    "~ " = ("insertText:", " ");
}

This avoids a common annoyance when editing headers in markdown files (eg in Bear).

System preferences

Here’s a configurure_system_preferences.sh script I use:

#!/usr/bin/env bash
#
# Configure MacOS settings.

set -e

function configure_all() {
    configure_keyboard
    configure_screensaver
    configure_screencapture
    configure_touchpad
}

function configure_keyboard() {
    # Set fast key repeat rate.
    defaults write NSGlobalDomain KeyRepeat -int 2
    defaults write NSGlobalDomain InitialKeyRepeat -int 15
}

function configure_screensaver() {
    # Require password as soon as screen-saver or sleep mode starts.
    defaults write com.apple.screensaver askForPassword -int 1
    defaults write com.apple.screensaver askForPasswordDelay -int 0
}

function configure_screencapture() {
    # Disable shadow effect in screen capture.
    defaults write com.apple.screencapture disable-shadow -bool true
}

function configure_touchpad() {
    defaults write com.apple.driver.AppleBluetoothMultitouch.trackpad Clicking -bool true
    defaults -currentHost write NSGlobalDomain com.apple.mouse.tapBehavior -int 1
}

configure_all

Further reading

• How to set up a new Mac for development - A 90 minute video walking through setting up a MacBook Pro.
• osx-for-hackers.sh — A large shell script with a lot of configuration options. This is the Yosemite/El Capitan edition – not everything works in Catalina. It’s worth browsing though to see if anything takes your fancy.

Python

General principles:

• Use pyenv to manage multiple versions of Python locally, and to stay out of the way of the system Python.

• Keep everything in virtualenvs.

• Use virtualenvwrapper to provide convenience commands. Mainly as I like to switch to a project with workon. Indeed, I often create virtualenvs for non-Python projects just so I jump to them with workon and run some initialisation in the postactivate script (like changing to the project directory and setting the iTerm tab title).

• Use pipx to install command-line Python apps like awscli that I want available globally (i.e. can be run without activating a virtualenv first).

Python versions

Install pyenv and pyenv-virtualenvwrapper:

brew install pyenv pyenv-virtualenvwrapper

and ensure these libraries are initialised by adding:

if which pyenv > /dev/null 2>&1
then
    # Pyenv (will add shims to front of $PATH)
    eval "$(pyenv init -)"

    # Ensure commands from virtualenvwrapper are available, no matter which
    # Python version is active. This is equiv to sourcing virtualenvwrapper.sh
    pyenv virtualenvwrapper
fi

to ~/.bash_profile.

Install a modern Python as the global default:

pyenv install 3.8.3
pyenv global 3.8.3

plus any other Python versions that projects require.

Python projects

For each Python project, create a virtualenv by selecting the appropriate Python version using pyenv then using mkvirtualenv:

cd $PATH_TO_PROJECT
pyenv local 3.7.7  # for example
mkvirtualenv $PROJECT_NAME

To avoid accidentally installing packages outside of a virtualenv, set:

# Always require a virtualenv to use pip
export PIP_REQUIRE_VIRTUALENV=true

in ~/.bash_profile. If you do want to run pip outside of a virtualenv, use something like:

PIP_REQUIRE_VIRTUALENV=false pip list

Python command-line apps

Install pipx with:

brew install pipx

and ensure ~/.local/bin is on your $PATH.

Install CLI apps:

pipx install awscli

Further reading

• My Python Development Environment, 2020 Edition by Jacob Kaplan-Moss (2019).