On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.9.0b4. Get it here:
This is a beta preview of Python 3.9
Python 3.9 is still in development. This release, 3.9.0b4, is the fourth of five planned beta release previews.
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.
Call to action
We strongly encourage maintainers of third-party Python projects to test with 3.9 during the beta phase and report issues found to the Python bug tracker https://bugs.python.org/ 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 (2020-08-10). Our goal is have no ABI changes after beta 5 and as few code changes as possible after 3.9.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.9 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 3.9 series, compared to 3.8
Some of the new major new features and changes in Python 3.9 are:
PEP 584 https://www.python.org/dev/peps/pep-0584/, Union Operators in dict
PEP 585 https://www.python.org/dev/peps/pep-0585/, Type Hinting Generics In Standard Collections
PEP 593 https://www.python.org/dev/peps/pep-0593/, Flexible function and variable annotations
PEP 602 https://www.python.org/dev/peps/pep-0602/, Python adopts a stable annual release cadence
PEP 615 https://www.python.org/dev/peps/pep-0615/, Support for the IANA Time Zone Database in the Standard Library
PEP 616 https://www.python.org/dev/peps/pep-0616/, String methods to remove prefixes and suffixes
PEP 617 https://www.python.org/dev/peps/pep-0617/, New PEG parser for CPython
BPO 38379 https://bugs.python.org/issue38379, garbage collection does not block on resurrected objects;
BPO 38692 https://bugs.python.org/issue38692, os.pidfd_open added that allows process management without races and signals;
BPO 39926 https://bugs.python.org/issue39926, Unicode support updated to version 13.0.0;
BPO 1635741 https://bugs.python.org/issue1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore;
A number of Python builtins (range, tuple, set, frozenset, list, dict) are now sped up using PEP 590 https://www.python.org/dev/peps/pep-0590 vectorcall;
A number of Python modules (_abc, audioop, _bz2, _codecs, _contextvars, _crypt, _functools, _json, _locale, operator, resource, time, _weakref) now use multiphase initialization as defined by PEP 489 https://www.python.org/dev/peps/pep-0489/;
A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384 https://www.python.org/dev/peps/pep-0384/.
(Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know mailto:firstname.lastname@example.org.)
The next pre-release, the fifth beta release of Python 3.9, will be 3.9.0b5. It is currently scheduled for 2020-07-20.
Online Documentation https://docs.python.org/3.9/ PEP 596 https://www.python.org/dev/peps/pep-0596/, 3.9 Release Schedule Report bugs at https://bugs.python.org https://bugs.python.org/. Help fund Python and its community https://discuss.python.org/psf/donations/. Your friendly release team, Ned Deily @nad https://discuss.python.org/u/nad Steve Dower @steve.dower https://discuss.python.org/u/steve.dower Łukasz Langa @ambv https://discuss.python.org/u/ambv