Homebrew¶

Homebrew is a package manager for macOS (and Linux). It installs system-level software, including Python itself.

What is Homebrew?¶

Homebrew installs system packages that aren't managed by pip or conda:

• Python interpreter
• Git, curl, wget
• Databases (PostgreSQL, Redis)
• Command-line tools
• Libraries (OpenSSL, libffi)

Website: https://brew.sh

Installation¶

macOS¶

bash /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Linux¶

bash /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Verify¶

bash brew --version

Basic Commands¶

Install Package¶

bash brew install python brew install git brew install postgresql

Upgrade Package¶

bash brew upgrade python brew upgrade # Upgrade all

Uninstall Package¶

bash brew uninstall python

Search Packages¶

bash brew search python

List Installed¶

bash brew list brew list --versions

Package Info¶

bash brew info python

Installing Python with Homebrew¶

Install Latest Python¶

bash brew install python

This installs:

• python3 command
• pip3 command
• Latest stable Python version

Check Installation¶

```bash which python3

/opt/homebrew/bin/python3 (Apple Silicon)¶

/usr/local/bin/python3 (Intel Mac)¶

python3 --version pip3 --version ```

Multiple Python Versions¶

```bash brew install python@3.10 brew install python@3.11 brew install python@3.12

Use specific version¶

python3.10 --version python3.11 --version ```

Homebrew vs pip vs conda¶

Typical Workflow¶

```bash

1. Install Python with Homebrew¶

brew install python

2. Create virtual environment¶

python3 -m venv myenv source myenv/bin/activate

3. Install Python packages with pip¶

pip install numpy pandas ```

Useful Packages for Python Development¶

```bash

Python interpreters¶

brew install python brew install python@3.10 brew install pypy3

Development tools¶

brew install git brew install gh # GitHub CLI brew install pre-commit

Databases¶

brew install postgresql brew install mysql brew install redis brew install sqlite

Data tools¶

brew install jq # JSON processor brew install csvkit # CSV tools

System libraries (sometimes needed by pip)¶

brew install openssl brew install libffi brew install zlib ```

Casks: GUI Applications¶

Homebrew Cask installs GUI applications:

```bash

IDEs and editors¶

brew install --cask visual-studio-code brew install --cask pycharm-ce

Terminals¶

brew install --cask iterm2

Database tools¶

brew install --cask dbeaver-community brew install --cask tableplus

General¶

brew install --cask docker brew install --cask slack ```

Services¶

Homebrew can manage background services:

```bash

Start PostgreSQL¶

brew services start postgresql

Stop PostgreSQL¶

brew services stop postgresql

Restart¶

brew services restart postgresql

List running services¶

brew services list ```

Maintenance¶

Update Homebrew¶

bash brew update # Update formula definitions

Upgrade All Packages¶

bash brew upgrade

Clean Up¶

bash brew cleanup # Remove old versions brew autoremove # Remove unused dependencies

Doctor (Troubleshooting)¶

bash brew doctor # Check for issues

Common Issues¶

Permission Errors¶

```bash

Fix permissions¶

sudo chown -R $(whoami) /opt/homebrew # Apple Silicon sudo chown -R $(whoami) /usr/local # Intel Mac ```

Conflicting Python Versions¶

```bash

See which Python is being used¶

which python3 python3 --version

Link specific version¶

brew link python@3.11 ```

PATH Issues¶

Add to ~/.zshrc or ~/.bashrc:

```bash

Apple Silicon Mac¶

eval "$(/opt/homebrew/bin/brew shellenv)"

Intel Mac¶

eval "$(/usr/local/bin/brew shellenv)" ```

Homebrew on Linux (Linuxbrew)¶

Homebrew also works on Linux:

```bash

Install¶

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Add to PATH¶

echo 'eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"' >> ~/.bashrc source ~/.bashrc ```

Useful for:

• Installing newer software than system packages
• Consistent tooling across macOS and Linux
• Avoiding sudo apt install permission issues

Summary¶

Key Takeaways¶

• Homebrew installs system packages (Python, Git, databases)
• Use Homebrew for Python interpreter, pip/conda for Python packages
• brew install --cask for GUI applications
• brew services manages background services
• Works on both macOS and Linux
• Run brew doctor to troubleshoot issues

Exercises¶

Exercise 1. Write the Homebrew commands to: (a) search for available Python versions, (b) install Python 3.12, and (c) verify which Python Homebrew installed by checking the path. Explain the difference between python3 from Homebrew vs the system Python on macOS.

Exercise 2. Write the Homebrew commands to: (a) install PostgreSQL, (b) start it as a background service, (c) check the service status, and (d) stop the service.

Exercise 3. Write the commands to: (a) list all installed Homebrew packages, (b) find which packages are outdated, (c) upgrade all packages, and (d) clean up old versions to free disk space.