Effortlessly Setting Up Multiple Python Versions (2.7 and 3.4) on a Mac

Managing multiple Python versions on a Mac can sometimes be a challenge. Fortunately, there are several effective ways to achieve this, allowing you to work with older and more recent versions of Python side by side without conflicts. This article will explore the best practices, including using Anaconda and managing Python versions with a version manager. We'll also discuss the benefits of using MacPorts to switch between Python versions.

Using Anaconda

The most straightforward and recommended approach is to use Anaconda. Anaconda is a powerful platform that simplifies the setup and management of multiple Python environments. By using Anaconda, you can easily set up different environments for Python 2.7 and 3.4, ensuring a smooth transition between versions as required.

To get started with Anaconda on a Mac, follow these steps:

Download and Install Anaconda: Visit the official Anaconda website and download the Python 2.7 and 3.4 distribution for macOS. Follow the installation instructions provided on the website. Create Separate Environments: Use the conda command to create separate environments for Python 2.7 and 3.4. For example:

    conda create -n py27 python2.7
    conda create -n py34 python3.4

Activate the Environment: You can switch between the environments using the conda activate command. For instance, to activate the Python 2.7 environment, run:

    conda activate py27

Install Required Packages: Install any necessary packages within the chosen environment using pip or conda install. Switch Environments as Needed: Whenever you need to switch between the environments, simply deactivate the current environment and activate the desired one:

    conda deactivate
    conda activate py34

For a detailed video tutorial on setting up multiple Python environments with Anaconda on a Mac, you can visit this link. This video will guide you through the process step-by-step, ensuring you can set up your environment quickly and efficiently.

Using Python Version Managers

Another effective way to manage multiple Python versions on a Mac is by using a version manager like pyenv. With a version manager, you can easily switch between different Python versions at runtime. Here’s how to set it up:

Install pyenv: You can install pyenv using Homebrew or by following the manual installation steps provided in the official documentation. Set Up pyenv Global Settings: Add the following lines to your ~_profile or ~/.zshrc file to ensure pyenv is loaded automatically:

    export PYENV_ROOT"$"
    export PATH"$PYENV_ROOT/bin:$PATH"
    eval "$(#{pyenv} init -)"

Install Python Versions: Use pyenv to install Python 2.7 and 3.4:

    pyenv install 2.7.18
    pyenv install 3.4.10

Switch Python Versions: To switch between Python versions, you can use the pyenv global or pyenv local commands. For example, to use Python 2.7 globally:

    pyenv global 2.7.18

Verify the Python Version: Run python --version to check the currently active Python version.

Using MacPorts

MacPorts is a ports collection with which you can build, install, and upgrade software on macOS. It can be particularly useful if you want to install software alongside multiple Python versions. Here’s how to use MacPorts to manage your Python versions:

Install MacPorts: Follow the installation instructions to set up MacPorts on your Mac. Install Python Versions: Use MacPorts to install Python 2.7 and 3.4:

    sudo port install python27
    sudo port install python34

Switch Between Python Versions: To switch between the Python versions, use the command:

    sudo port select --set python python27
    sudo port select --set python python34

Verify the Python Version: Open a terminal and run which python to check which Python version is selected.

By utilizing MacPorts, you can ensure that your Python installations are managed as build tools, allowing for easy switching between versions as needed.

Conclusion

Setting up multiple Python versions on a Mac can be a necessity for developers who work with projects that require different versions of Python. By using tools like Anaconda, pyenv, or MacPorts, you can manage these versions efficiently and switch between them with ease. Regardless of your choice, the key is to have a reliable method to isolate dependencies and ensure that your development environment remains clean and consistent.