[RELEASE] Python 3.9.0rc1 is now available

[Miro Hrončok]

This has been updated in Fedora rawhide.

The Fedora 33 update waits for the successful compose:
https://bodhi.fedoraproject.org/updates/FEDORA-2020-3d34a62850

The updates appear to be ABI compatible, so there is no need for a targeted rebuild.

Fedora 32 and 31 updates are pending:
https://bodhi.fedoraproject.org/updates/FEDORA-2020-ce74609c79
https://bodhi.fedoraproject.org/updates/FEDORA-2020-85cca90ce8


-------- Forwarded Message --------
Subject: 	[Python-Dev] [RELEASE] Python 3.9.0rc1 is now available
Date: 	Tue, 11 Aug 2020 23:48:59 +0200
From: 	Łukasz Langa <lukasz(a)langa.pl&gt;
To: 	python-committers(a)python.org, python-dev(a)python.org, 
python-list(a)python.org, python-announce(a)python.org



Python 3.9.0 is*almost*ready. This release,*3.9.0rc1*, is the penultimate 
release preview. You can get it here:

https://www.python.org/downloads/release/python-390rc1/

Entering the release candidate phase, only reviewed code changes which are clear 
bug fixes are allowed between this release candidate and the final release. The 
second candidate and the last planned release preview is currently planned for 
2020-09-14.

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


     Calls to action


         Core developers: all eyes on the docs now

   * Are all*your*changes properly documented?
   * Did you notice*other*changes you know of to have insufficient documentation?


         Community members

We*strongly encourage*maintainers of third-party Python projects to prepare 
their projects for 3.9 compatibility during this phase. As always, report any 
issues tothe Python bug tracker <https://bugs.python.org/>;.


     Installer 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.


     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 usingPEP 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 byPEP 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 byPEP 384 <https://www.python.org/dev/peps/pep-0384/>;.