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Python 3.9.0

Release Date: Oct. 5, 2020

This is the stable release of Python 3.9.0

Python 3.9.0 is the newest major release of the Python programming language, and it contains many new features and optimizations.

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 573, Module State Access from C Extension Methods
  • 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 614, Relaxing Grammar Restrictions On Decorators
  • 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.

You can find a more comprehensive list in this release's "What's New" document.

More resources

And now for something completely different

Wapcaplet: (John Cleese) Welcome! Do sit down. My name's Wapcaplet, Adrian Wapcaplet.
Mr. Simpson: how'd'y'do.
Wapcaplet: Now, Mr. Simpson... Now, I understand you want us to advertise your washing powder.
S: String.
W: String, washing powder, what's the difference. We can sell anything.
S: Good. Well I have this large quantity of string, a hundred and twenty-two thousand miles of it to be exact, which I inherited, and I thought if I advertised it...
W: Of course! A national campaign. Useful stuff, string, no trouble there.
S: Ah, but there's a snag, you see. Due to bad planning, the hundred and twenty-two thousand miles is in three inch lengths. So it's not very useful.
W: Well, that's our selling point! 'SIMPSON'S INDIVIDUAL STRINGETTES!'
S: What?
W: 'THE NOW STRING! READY CUT, EASY TO HANDLE, SIMPSON'S INDIVIDUAL EMPEROR STRINGETTES - JUST THE RIGHT LENGTH!'
S: For what?
W: 'A MILLION HOUSEHOLD USES!'
S: Such as?
W: Uhmm...Tying up very small parcels, attatching notes to pigeons' legs, uh, destroying household pests...
S: Destroying household pests?! How?
W: Well, if they're bigger than a mouse, you can strangle them with it, and if they're smaller than, you flog them to death with it!
S: Well surely!....
W: 'DESTROY NINETY-NINE PERCENT OF KNOWN HOUSEHOLD PESTS WITH PRE-SLICED, RUSTPROOF, EASY-TO-HANDLE, LOW CALORIE SIMPSON'S INDIVIDUAL EMPEROR STRINGETTES, FREE FROM ARTIFICIAL COLORING, AS USED IN HOSPITALS!'

Full Changelog

Files

Version Operating System Description MD5 Sum File Size GPG
Gzipped source tarball Source release e19e75ec81dd04de27797bf3f9d918fd 26724009 SIG
XZ compressed source tarball Source release 6ebfe157f6e88d9eabfbaf3fa92129f6 18866140 SIG
macOS 64-bit installer Mac OS X for OS X 10.9 and later 16ca86fa3467e75bade26b8a9703c27f 31132316 SIG
Windows help file Windows 9ea6fc676f0fa3b95af3c5b3400120d6 8757017 SIG
Windows x86-64 embeddable zip file Windows for AMD64/EM64T/x64 60d0d94337ef657c2cca1d3d9a6dd94b 8387074 SIG
Windows x86-64 executable installer Windows for AMD64/EM64T/x64 b61a33dc28f13b561452f3089c87eb63 28158664 SIG
Windows x86-64 web-based installer Windows for AMD64/EM64T/x64 733df85afb160482c5636ca09b89c4c8 1364352 SIG
Windows x86 embeddable zip file Windows d81fc534080e10bb4172ad7ae3da5247 7553872 SIG
Windows x86 executable installer Windows 4a2812db8ab9f2e522c96c7728cfcccb 27066912 SIG
Windows x86 web-based installer Windows cdbfa799e6760c13d06d0c2374110aa3 1327384 SIG