5. Using Python on macOS¶

5.1.1. Installation steps¶

For current Python versions (other than those in security status), the release team produces a Python for macOS installer package for each new release. A list of available installers is available here. We recommend using the most recent supported Python version where possible. Current installers provide a universal2 binary build of Python which runs natively on all Macs (Apple Silicon and Intel) that are supported by a wide range of macOS versions, currently typically from at least macOS 10.13 High Sierra on.

The downloaded file is a standard macOS installer package file (.pkg). File integrity information (checksum, size, sigstore signature, etc) for each file is included on the release download page. Installer packages and their contents are signed and notarized with Python Software Foundation Apple Developer ID certificates to meet macOS Gatekeeper requirements.

For a default installation, double-click on the downloaded installer package file. This should launch the standard macOS Installer app and display the first of several installer windows steps.

Clicking on the Continue button brings up the Read Me for this installer. Besides other important information, the Read Me documents which Python version is going to be installed and on what versions of macOS it is supported. You may need to scroll through to read the whole file. By default, this Read Me will also be installed in /Applications/Python 3.13/ and available to read anytime.

Clicking on Continue proceeds to display the license for Python and for other included software. You will then need to Agree to the license terms before proceeding to the next step. This license file will also be installed and available to be read later.

After the license terms are accepted, the next step is the Installation Type display. For most uses, the standard set of installation operations is appropriate.

By pressing the Customize button, you can choose to omit or select certain package components of the installer. Click on each package name to see a description of what it installs. To also install support for the optional experimental free-threaded feature, see Installing Free-threaded Binaries.

In either case, clicking Install will begin the install process by asking permission to install new software. A macOS user name with Administrator privilege is needed as the installed Python will be available to all users of the Mac.

When the installation is complete, the Summary window will appear.

Double-click on the Install Certificates.command icon or file in the /Applications/Python 3.13/ window to complete the installation.

This will open a temporary Terminal shell window that will use the new Python to download and install SSL root certificates for its use.

If Successfully installed certifi and update complete appears in the terminal window, the installation is complete. Close this terminal window and the installer window.

A default install will include:

• A Python 3.13 folder in your Applications folder. In here you find IDLE, the development environment that is a standard part of official Python distributions; and Python Launcher, which handles double-clicking Python scripts from the macOS Finder.

• A framework /Library/Frameworks/Python.framework, which includes the Python executable and libraries. The installer adds this location to your shell path. To uninstall Python, you can remove these three things. Symlinks to the Python executable are placed in /usr/local/bin/.

5.1.2. How to run a Python script¶

There are two ways to invoke the Python interpreter. If you are familiar with using a Unix shell in a terminal window, you can invoke python3.13 or python3 optionally followed by one or more command line options (described in Command line and environment). The Python tutorial also has a useful section on using Python interactively from a shell.

You can also invoke the interpreter through an integrated development environment. IDLE — Python editor and shell is a basic editor and interpreter environment which is included with the standard distribution of Python. IDLE includes a Help menu that allows you to access Python documentation. If you are completely new to Python, you can read the tutorial introduction in that document.

There are many other editors and IDEs available, see Editors and IDEs for more information.

To run a Python script file from the terminal window, you can invoke the interpreter with the name of the script file:

python3.13 myscript.py

To run your script from the Finder, you can either:

• Drag it to Python Launcher.

• Select Python Launcher as the default application to open your script (or any .py script) through the Finder Info window and double-click it. Python Launcher has various preferences to control how your script is launched. Option-dragging allows you to change these for one invocation, or use its Preferences menu to change things globally.

Be aware that running the script directly from the macOS Finder might produce different results than when running from a terminal window as the script will not be run in the usual shell environment including any setting of environment variables in shell profiles. And, as with any other script or program, be certain of what you are about to run.