Assuming no critical problems are found prior to 2020-12-11, the currently scheduled release date for 3.9.1, no code changes are planned between this release candidate and the final release. That being said, please keep in mind that this is a pre-release of 3.9.1 and as such its main purpose is testing.
Maintenance releases for the 3.9 series will continue at regular bi-monthly intervals, with 3.9.2 planned for end of January 2021.
3.9.1rc1 is the first version of Python to support macOS 11 Big Sur. With
Xcode 11 and later it is now possible to build “Universal 2” binaries
which work on Apple Silicon. We are providing such an installer as the macosx11.0
variant. This installer can be deployed back to older versions, tested
down to OS X 10.9. As we are waiting for an updated version of pip, please consider the macosx11.0 installer experimental.
This work would not have been possible without the effort of Ronald Oussoren, Ned Deily, and Lawrence D’Anna from Apple. Thank you!
In other news, this is the first version of Python to default to the 64-bit installer on Windows. The installer now also actively disallows installation on Windows 7. Python 3.9 is incompatible with this unsupported version of Windows.
We’ve made 240 changes since v3.9.0 which is a significant amount. To compare, 3.8.1rc1 only saw 168 commits since 3.8.0. See the full change log at
https://docs.python.org/release/3.9.1rc1/whatsnew/changelog.html.
For more information about features included in the 3.9 series, see the “What’s New in Python 3.9” document.
There’s additional work needed to make this release support macOS 11 Big Sur. This should be ready next week, stay tuned.
Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organization contributions to the Python Software Foundation.
Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv