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Python 3.9.0b5

Release Date: July 20, 2020

This is a beta preview of Python 3.9

Python 3.9 is still in development. This release, 3.9.0b5, is the last 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 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, Union Operators in dict
  • PEP 585, Type Hinting Generics In Standard Collections
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • PEP 615, Support for the IANA Time Zone Database in the Standard Library
  • PEP 616, String methods to remove prefixes and suffixes
  • PEP 617, New PEG parser for CPython
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0;
  • BPO 1635741, 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 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;
  • 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.

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

The next pre-release, the first release candidate of Python 3.9.0, will be 3.9.0rc1. It is currently scheduled for 2020-08-10.

More resources

And now for something completely different

Whenever life gets you down, Mrs. Brown,
And things seem hard or tough,
And people are stupid, obnoxious or daft,
And you feel that you've had quite eno-o-o-o-o-ough,

Just remember that you're standing on a planet that's evolving
And revolving at 900 miles an hour.
It's orbiting at 19 miles a second, so it's reckoned,
The sun that is the source of all our power.
Now the sun, and you and me, and all the stars that we can see,
Are moving at a million miles a day,
In the outer spiral arm, at 40,000 miles an hour,
Of a galaxy we call the Milky Way.

Full Changelog


Version Operating System Description MD5 Sum File Size GPG
Gzipped source tarball Source release bd8ded2aa53082f15c467063bc14096b 25024809 SIG
XZ compressed source tarball Source release 1f66c49ba74307cdc70754ddbb88e7f9 18588472 SIG
macOS 64-bit installer Mac OS X for OS X 10.9 and later 3f6f5efd8fd90d793a7e40c6be28b403 29417507 SIG
Windows help file Windows 56c416efd1e14f32625f9a1929deca8f 8730975 SIG
Windows x86-64 embeddable zip file Windows for AMD64/EM64T/x64 b8724cf9410dcbba2eddaf0c70d98728 8382217 SIG
Windows x86-64 executable installer Windows for AMD64/EM64T/x64 3780e3bc9afdad905723edeed5fd12fc 28369960 SIG
Windows x86-64 web-based installer Windows for AMD64/EM64T/x64 3caa20c22a8fb4d38bd2b2f2825cc8db 1364448 SIG
Windows x86 embeddable zip file Windows 82f184ef6041794723a0945fc9ead994 7547003 SIG
Windows x86 executable installer Windows 07e55f955639b6bda42c8907f365f854 27284896 SIG
Windows x86 web-based installer Windows ed87eaada9776196f35f83e0f03b12e3 1328496 SIG