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Python 3.8.0rc1

Release Date: Oct. 1, 2019

This is the release candidate of Python 3.8.0

This release, 3.8.0rc1, is the final planned release preview. Assuming no critical problems are found prior to 2019-10-14, the scheduled release date for 3.8.0, no code changes are planned between this release candidate and the final release.

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

Major new features of the 3.8 series, compared to 3.7

Some of the new major new features and changes in Python 3.8 are:

  • PEP 572, Assignment expressions
  • PEP 570, Positional-only arguments
  • PEP 587, Python Initialization Configuration (improved embedding)
  • PEP 590, Vectorcall: a fast calling protocol for CPython
  • PEP 578, Runtime audit hooks
  • PEP 574, Pickle protocol 5 with out-of-band data
  • Typing-related: PEP 591 (Final qualifier), PEP 586 (Literal types), and PEP 589 (TypedDict)
  • Parallel filesystem cache for compiled bytecode
  • Debug builds share ABI as release builds
  • f-strings support a handy = specifier for debugging
  • continue is now legal in finally: blocks
  • on Windows, the default asyncio event loop is now ProactorEventLoop
  • on macOS, the spawn start method is now used by default in multiprocessing
  • multiprocessing can now use shared memory segments to avoid pickling costs between processes
  • typed_ast is merged back to CPython
  • LOAD_GLOBAL is now 40% faster
  • pickle now uses Protocol 4 by default, improving performance
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Ɓukasz know.)

There are many other interesting changes, please consult the "What's New" page in the documentation for a full list.

More resources

And now for something completely different

WISE MAN #1: We are three wise men.
MANDY: Well, what are you doing creeping around a cow shed at two o'clock in the morning? That doesn't sound very wise to me.
WISE MAN #3: We are astrologers.
WISE MAN #1: We have come from the East.
MANDY: Is this some kind of joke?
WISE MAN #2: We wish to praise the infant.
WISE MAN #1: We must pay homage to him.
MANDY: Homage? You're all drunk. It's disgusting. Out! The lot, out!

Full Changelog

Files

Version Operating System Description MD5 Sum File Size GPG
Gzipped source tarball Source release 3e1be2f9a8a73dae196d04f23c90d749 23945154 SIG
XZ compressed source tarball Source release edf19210b01ff2d77169ccb1d77e244c 17812764 SIG
macOS 64-bit installer Mac OS X for OS X 10.9 and later a9a1e46cf083a97ab4b7dbb91808028d 28995422 SIG
Windows help file Windows d2fb2407f3f2b77de1198c0cd98159b3 8455530 SIG
Windows x86-64 embeddable zip file Windows for AMD64/EM64T/x64 1be113668100b937bf0f7171806bf221 8079786 SIG
Windows x86-64 executable installer Windows for AMD64/EM64T/x64 ed7a7fa4d96577d9aa6948f125374426 27496600 SIG
Windows x86-64 web-based installer Windows for AMD64/EM64T/x64 450c62e368d6b27882c33494817479f3 1363904 SIG
Windows x86 embeddable zip file Windows f41a1888597ec844fd66b6dd8a42239a 7212649 SIG
Windows x86 executable installer Windows bd2fa3653c21a03f47a582a9be561126 26399904 SIG
Windows x86 web-based installer Windows 419db1a38595b1ab3730e3b6f764a901 1325896 SIG