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Python 3.13.0b3

Release Date: June 27, 2024

This is a beta preview of Python 3.13

Python 3.13 is still in development. This release, 3.13.0b3, is the third of four beta release previews of 3.13.

Beta release previews are intended to give the wider community the opportunity to test new features and bug fixes and to prepare their projects to support the new feature release.

We strongly encourage maintainers of third-party Python projects to test with 3.13 during the beta phase and report issues found to the Python bug tracker as soon as possible. While the release is planned to be feature complete entering the beta phase, it is possible that features may be modified or, in rare cases, deleted up until the start of the release candidate phase (Tuesday 2024-07-30). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after 3.13.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.13 as possible during the beta phase.

Please keep in mind that this is a preview release and its use is not recommended for production environments.

Major new features of the 3.13 series, compared to 3.12

Some of the new major new features and changes in Python 3.13 are:

New features

  • A new and improved interactive interpreter, based on PyPy's, featuring multi-line editing and color support, as well as colorized exception tracebacks.
  • An experimental free-threaded build mode, which disables the Global Interpreter Lock, allowing threads to run more concurrently. The build mode is available as an experimental feature in the Windows and macOS installers as well.
  • A preliminary, experimental JIT, providing the ground work for significant performance improvements.
  • The (cyclic) garbage collector is now incremental, which should mean shorter pauses for collection in programs with a lot of objects.
  • A modified version of mimalloc is now included, optional but enabled by default if supported by the platform, and required for the free-threaded build mode.
  • Docstrings now have their leading indentation stripped, reducing memory use and the size of .pyc files. (Most tools handling docstrings already strip leading indentation.)
  • The dbm module has a new dbm.sqlite3 backend that is used by default when creating new files.
  • The minimum supported macOS version was changed from 10.9 to 10.13 (High Sierra). Older macOS versions will not be supported going forward.


Removals and new deprecations

  • PEP 594 (Removing dead batteries from the standard library) scheduled removals of many deprecated modules: aifc, audioop, chunk, cgi, cgitb, crypt, imghdr, mailcap, msilib, nis, nntplib, ossaudiodev, pipes, sndhdr, spwd, sunau, telnetlib, uu, xdrlib, lib2to3.
  • Many other removals of deprecated classes, functions and methods in various standard library modules.
  • C API removals and deprecations. (Some removals present in alpha 1 were reverted in alpha 2, as the removals were deemed too disruptive at this time.)
  • New deprecations, most of which are scheduled for removal from Python 3.15 or 3.16.

(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 3.13, see What's new in Python 3.13. The next pre-release of Python 3.13 will be 3.13.0b4, currently scheduled for 2024-07-16.

More resources

Full Changelog


Version Operating System Description MD5 Sum File Size GPG Sigstore SBOM
Gzipped source tarball Source release 3c61aea8af036468fcc0784a7f7c6345 26.2 MB SIG .sigstore SPDX
XZ compressed source tarball Source release 15b5c3e8ddf68a311a9ebc9c2325a9d1 19.9 MB SIG .sigstore SPDX
macOS 64-bit universal2 installer macOS for macOS 10.13 and later 04bf21168cefb1c5ed7eb83796b077b3 65.4 MB SIG .sigstore
Windows installer (64-bit) Windows Recommended 2887787efc457e625e2fe3dc38a91424 25.4 MB SIG .sigstore SPDX
Windows installer (ARM64) Windows Experimental 9b3399c003e7b3f582254a7999edaa04 24.6 MB SIG .sigstore SPDX
Windows embeddable package (64-bit) Windows 0f1f80e4311a4394c824ce5081a535b7 11.9 MB SIG .sigstore SPDX
Windows embeddable package (32-bit) Windows 4bbfe93448045990f25f3ce6af9fe221 10.4 MB SIG .sigstore SPDX
Windows embeddable package (ARM64) Windows ff504f3b106f526a98e7338b7f88fe78 10.9 MB SIG .sigstore SPDX
Windows installer (32 -bit) Windows 5f0c3062d2d583f13ed790f0614a1cc1 24.1 MB SIG .sigstore SPDX