Release Date: April 28, 2020

This is an early developer preview of Python 3.9

Python 3.9 is still in development. This release, 3.9.0a6 is the last out of six planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2020-05-18) and, if necessary, may be modified or deleted up until the release candidate phase (2020-08-10). 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

Many new features for Python 3.9 are still being planned and written. Among the new major new features and changes so far:

• 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 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 Łukasz know.)

The next pre-release, the first beta release of Python 3.9, will be 3.9.0b1. It is currently scheduled for 2020-05-18.

More resources

• Online Documentation
• PEP 596, 3.9 Release Schedule
• Report bugs at https://bugs.python.org.
• Help fund Python and its community.

And now for something completely different

Scientist (Graham Chapman): Standard IQ tests gave the following results. The penguins scored badly when compared with primitive human sub-groups like the bushmen of the Kalahari but better than BBC program planners.
Scientist: These IQ tests were thought to contain an unfair cultural bias against the penguin. For example, it didn't take into account the penguins extremely poor educational system. To devise a fairer system of test, a team of our researchers spent eighteen months in Antarctica living like penguins, and subsequently dying like penguins - only quicker - proving that the penguin is a clever little sod in his own environment.

Full Changelog