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Python 3.9.0a1

Warning: Python 3.9.0 reached end-of-life on 2025-10-31. It is no longer supported and does not receive security updates. We recommend upgrading to the latest Python release.
Note: Python 3.9.0a1 has been superseded by Python 3.9.25.

Release date: Nov. 19, 2019

This is an early developer preview of Python 3.9

Major new features of the 3.9 series, compared to 3.8

Python 3.9 is still in development. This releasee, 3.9.0a1 is the first 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.

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

  • PEP 602, Python adopts a stable annual release cadence
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • 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 of Python 3.9 will be 3.9.0a2, currently scheduled for 2019-12-16.

More resources

And now for something completely different

Eric: Ladies and gentlemen, seldom can it have been a greater pleasure and privilege than it is for me now to announce that the next award gave me the great pleasure and privilege of asking a man without whose ceaseless energy and tireless skill the British Film Industry would be today. I refer of course to my friend and colleague, Mr David Niven.
Eric: Sadly, David Niven cannot be with us tonight, but he has sent his fridge.
(the fridge with a black tie on is pushed down by the men in brown coats, and a microphone is positioned in front of it)
Eric: This is the fridge in which David keeps most of his milk, butter and eggs. What a typically selfless gesture, that he should send this fridge, of all of his fridges, to be with us tonight.

Files

Version Operating system Description File size GPG MD5 checksum
Gzipped source tarball Source release 23.0 MB SIG a75fb1ad4371195de74430f2e8d6492c
XZ compressed source tarball Source release 17.1 MB SIG 43d57843ad4e4a7627c04930d109e6f9
macOS 64-bit installer macOS for OS X 10.9 and later 26.9 MB SIG ac49f3b05d87f4d0900fc0a60da6ed1c
Windows help file Windows 8.2 MB SIG 2d7431bd23edb7b1b154b8ca6b684f6d
Windows x86 embeddable zip file Windows 6.9 MB SIG abfdbed5a8475acfe32612550e7cb233
Windows x86 executable installer Windows 25.4 MB SIG 198099ef5fc6cd203cde95baf724eaad
Windows x86 web-based installer Windows 1.3 MB SIG 2265f00d0a9fc2448a80c4baa5fc43ef
Windows x86-64 embeddable zip file Windows for AMD64/EM64T/x64 7.7 MB SIG 5f59c69bbe50a754b989f827a83c0690
Windows x86-64 executable installer Windows for AMD64/EM64T/x64 26.4 MB SIG faddbef6a2ecaecfa83755b2ddcf5a8f
Windows x86-64 web-based installer Windows for AMD64/EM64T/x64 1.3 MB SIG 996aeb680beca765d049719c2f1843ae