As part of the macOS Monterey 12.3 beta cycle, Apple included the following note in the publicly accessible release notes for the macOS Monterey 12.3 beta release:

https://developer.apple.com/documentation/macos-release-notes/macos-12_3-release-notes

This is a development which Apple has warned about for a while, beginning with macOS Catalina’s release notes:

https://developer.apple.com/documentation/macos-release-notes/macos-catalina-10_15-release-notes

Apple has not included a Python 3 runtime with macOS Monterey, so the removal of Python 2.7 from macOS 12.3 and later will mean that Apple is no longer shipping a Python runtime as part of macOS.

For those who want or need to use an Apple-supplied Python distribution, Python 3 is included as part of Xcode and the Xcode Command Line Tools. Those tools are not part of macOS and will need to be installed separately.

As an alternative, a number of shops have been deploying their own Python 3 distribution. For more information on this, please see Greg Neagle’s Snakes on a Plan session from MacSysAdmin 2020:

Session slides:
http://docs.macsysadmin.se/2020/pdf/SnakesOnAPlan.pdf

Session video:
http://docs.macsysadmin.se/2020/video/Day1Session1.mp4