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Python 3.12.0rc3

Release Date: Sept. 19, 2023

This is the third release candidate of Python 3.12.0

This release, 3.12.0rc3, is the absolutely last release preview for Python 3.12.

There will be no ABI changes from this point forward in the 3.12 series. The intent is for the final release of 3.12.0, scheduled for Monday, 2023-10-02, to be identical to this release candidate. This really is the last chance to find critical problems in Python 3.12.

Call to action

We strongly encourage maintainers of third-party Python projects to prepare their projects for 3.12 compatibilities during this phase, and where necessary publish Python 3.12 wheels on PyPI to be ready for the final release of 3.12.0. Any binary wheels built against Python 3.12.0rc3 will work with future versions of Python 3.12. As always, report any issues to the Python bug tracker.

Please keep in mind that this is a preview release and while it's as close to the final release as we can get it, its use is not recommended for production environments.

Core developers: time to work on documentation now

  • Are all your changes properly documented?
  • Are they mentioned in What's New?
  • Did you notice other changes you know of to have insufficient documentation?

Major new features of the 3.12 series, compared to 3.11

New features

Type annotations


  • The deprecated wstr and wstr_length members of the C implementation of unicode objects were removed, per PEP 623.
  • In the unittest module, a number of long deprecated methods and classes were removed. (They had been deprecated since Python 3.1 or 3.2).
  • The deprecated smtpd and distutils modules have been removed (see PEP 594 and PEP 632. The setuptools package continues to provide the distutils module.
  • A number of other old, broken and deprecated functions, classes and methods have been removed.
  • Invalid backslash escape sequences in strings now warn with SyntaxWarning instead of DeprecationWarning, making them more visible. (They will become syntax errors in the future.)
  • The internal representation of integers has changed in preparation for performance enhancements. (This should not affect most users as it is an internal detail, but it may cause problems for Cython-generated code.)

(Hey, fellow core developer, if a feature you find important is missing from this list, let Thomas know.)

For more details on the changes to Python 3.12, see What's new in Python 3.12. The next scheduled release of Python 3.12 will be 3.12.0, the final release, currently scheduled for 2023-10-02.

More resources


Version Operating System Description MD5 Sum File Size GPG Sigstore
Gzipped source tarball Source release 052797f64d8bd6354b294aad146c5cb3 25.9 MB SIG .sigstore
XZ compressed source tarball Source release cead7d4428e88e8de9219731c21edb74 19.6 MB SIG .sigstore
macOS 64-bit universal2 installer macOS for macOS 10.9 and later 9424c5ef7af30422f060cb8e2c3c31eb 43.3 MB SIG .sigstore
Windows installer (64-bit) Windows Recommended 176f3ea892c06b739097307a00f73cb6 25.3 MB SIG .sigstore
Windows installer (ARM64) Windows Experimental b6b36b14564e15ddea1f95fe58d9f468 24.6 MB SIG .sigstore
Windows embeddable package (64-bit) Windows de54c188e182fb09cbf2395ee414bd30 10.5 MB SIG .sigstore
Windows embeddable package (32-bit) Windows b6ed11598c929af946a110ca4db0d95c 9.4 MB SIG .sigstore
Windows embeddable package (ARM64) Windows 728cbbfd0d5fc485233e1aba7884a773 9.8 MB SIG .sigstore
Windows installer (32 -bit) Windows 680cfd8f909b867e520ceb4ae5674db6 24.0 MB SIG .sigstore