This package will install Python $FULL_VERSION for macOS $MACOSX_DEPLOYMENT_TARGET for the following architecture(s): $ARCHITECTURES.

NOTE: Python 2 reaches end-of-life in 2020 and will no longer be supported or updated thereafter.  You should upgrade to Python 3 as soon as you can.  Read more here.

Certificate verification and OpenSSL

This package includes its own private copy of OpenSSL 1.0.2.   The trust certificates in system and user keychains managed by the Keychain Access application and the security command line utility are not used as defaults by the Python ssl module.  A sample command script is included in /Applications/Python 2.7 to install a curated bundle of default root certificates from the third-party certifi package (https://pypi.org/project/certifi/).  Double-click on Install Certificates to run it.

The bundled pip has its own default certificate store for verifying download connections.

Which installer variant should I use?

In almost all cases, you should use the macOS 64-bit installer for OS X 10.9 and later.

The legacy macOS 64-bit/32-bit installer for Mac OS X 10.6 and later variant  is now deprecated.  macOS 10.6 Snow Leopard was released in 2009 and has not been supported by Apple for many years including lack of security updates.  It is becoming increasingly difficult to ensure new Python features and bug fixes are compatible with such old systems.  Note that, due to recent Apple installer packaging changes, the 10.6+ installer pkg we provide can no longer be opened by the Apple system installer application on 10.6;  10.7 and 10.8 are not affected.  We believe that there is now very little usage of this installer variant and so we would like to focus our resources on supporting newer systems.  We do not plan to intentionally break Python support on 10.6 through 10.8 and we will consider bug fixes for problems found when building from source on those systems through the support window of Python 2.7.  macOS 10.15 Catalina removes support for running 32-bit architecture programs; we do not recommend trying to use the 10.6+ variant on it and it may not install on 10.15 systems without intervention. 

Using IDLE or other Tk applications 

This package includes its own private version of Tcl/Tk 8.6. It does not use any system-supplied or third-party supplied versions of Tcl/Tk.

Due to new security checks on macOS 10.15 Catalina, when launching IDLE macOS may open a window with a message "Python" would like to access files in your Documents folder.  This is normal as IDLE uses your Documents folder as its default when opening and saving files; you can still choose other locations in the Open and Save file dialog windows.  Click on the OK button to proceed.

Other changes

For other changes in this release, see the What's new section in the Documentation Set for this release and its Release Notes link at https://www.python.org/downloads/.