How to install Python 2 on macOS 12.3+

Learn how to install python 2 on macos 12.3+ with practical examples, diagrams, and best practices. Covers python, macos, python-2.7 development techniques with visual explanations.
Tags:
Categories:

Installing Python 2 on macOS 12.3+ (Monterey and Newer)

Installing Python 2 on macOS 12.3+ (Monterey and Newer)

A comprehensive guide to successfully installing and managing Python 2.7 on modern macOS versions using Homebrew, addressing common challenges and best practices.

While Python 3 is the current standard, there are still legacy applications and projects that require Python 2.7. Modern macOS versions, specifically macOS 12.3 (Monterey) and later, no longer ship with Python 2.7 pre-installed. This article will walk you through the process of installing Python 2.7 on these systems using Homebrew, ensuring you can support older codebases without compromising your system's stability.

Understanding Python 2's End-of-Life and macOS Changes

Python 2.7 officially reached its end-of-life (EOL) on January 1, 2020. This means it no longer receives official support, security updates, or bug fixes. For new projects, always use Python 3. However, for maintaining existing systems, Python 2.7 might still be a necessity. macOS removed Python 2.7 from its default installation starting with macOS Monterey (12.3), primarily due to its EOL status and the shift towards modern development practices. Attempting to run python in your terminal on a clean install of macOS 12.3+ will result in a 'command not found' error.

Prerequisites: Homebrew Installation

Homebrew is a free and open-source software package management system that simplifies the installation of software on macOS. If you don't have Homebrew installed, you'll need to install it first. Open your Terminal application (found in /Applications/Utilities) and run the following command:

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

Command to install Homebrew on macOS

Follow the on-screen instructions, which may include entering your macOS user password. Once installed, it's a good practice to run brew doctor to ensure everything is set up correctly.

Installing Python 2.7 with Homebrew

Homebrew maintains a tap for older, deprecated packages, including Python 2.7. You'll first need to tap this repository, then you can install Python 2.7. After installation, you'll need to ensure your shell's PATH variable is correctly configured to locate the newly installed Python 2.7.

1. Step 1

Tap the Homebrew homebrew/cask-versions repository, which contains older software versions: brew tap homebrew/cask-versions

2. Step 2

Install Python 2.7 using Homebrew: brew install python@2

3. Step 3

Verify the installation by checking the Python 2 version: python2 --version (This should output Python 2.7.18 or similar)

4. Step 4

Add Python 2 to your PATH. Homebrew typically symlinks it, but you might need to add the Homebrew bin directory to your shell's PATH. For Zsh (default on modern macOS): echo 'export PATH="/usr/local/opt/python@2/bin:$PATH"' >> ~/.zshrc

5. Step 5

Reload your shell configuration for changes to take effect: source ~/.zshrc

6. Step 6

Confirm Python 2 is now accessible by typing python2 and then python to see which version is picked up. Python 3 should remain your default python if you have it installed.

python2 --version
# Expected output: Python 2.7.18

which python2
# Expected output: /usr/local/bin/python2

Commands to verify Python 2 installation and its path

Managing Python 2.7 Environments with virtualenv

For projects requiring Python 2.7, it's highly recommended to use virtualenv to create isolated environments. This prevents conflicts between project dependencies and avoids cluttering your global Python installations. First, you need to install pip2 (Python 2's package installer), then virtualenv for Python 2.

1. Step 1

Install pip2 for Python 2.7: curl https://bootstrap.pypa.io/pip/2.7/get-pip.py | python2

2. Step 2

Install virtualenv for Python 2.7 using pip2: pip2 install virtualenv

3. Step 3

Navigate to your project directory: cd ~/my_python2_project

4. Step 4

Create a Python 2 virtual environment: virtualenv -p python2 venv

5. Step 5

Activate the virtual environment: source venv/bin/activate

6. Step 6

Deactivate the virtual environment when done: deactivate

pip2 install virtualenv
mkdir my_python2_project
cd my_python2_project
virtualenv -p python2 venv
source venv/bin/activate
python --version # Should show Python 2.7.x
pip install requests==2.20.0 # Example: install a Python 2 compatible package
deactivate

Steps to create, activate, and use a Python 2 virtual environment

A flowchart diagram illustrating the process of installing Python 2 on macOS 12.3+ using Homebrew and setting up a virtual environment. Steps include: Check Homebrew, Install Python 2, Configure PATH, Install pip2, Install virtualenv, Create virtual environment, Activate virtual environment. Use light blue boxes for actions, green for verification, and arrows for flow. Clean, technical style.

Workflow for Python 2.7 installation and virtual environment setup on macOS

By following these steps, you can successfully install and manage Python 2.7 on your macOS 12.3+ system, allowing you to work with legacy projects while keeping your primary Python 3 environment clean and up-to-date. Remember to always prioritize Python 3 for new development and be aware of the security considerations when using end-of-life software.