Python 3.8.7rc1

Release date: Dec. 7, 2020

This is the release candidate of the seventh maintenance release of Python 3.8

Note: The release you're looking at is Python 3.8.7rc1, a bugfix release for the legacy 3.8 series. Python 3.11 is now the latest feature release series of Python 3. Get the latest release of 3.11.x here.

Major new features of the 3.8 series, compared to 3.7

• 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

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

More resources

• Online Documentation
• PEP 569, 3.8 Release Schedule
• Report bugs at https://bugs.python.org.
• Help fund Python and its community.

Windows users

• The binaries for AMD64 will also work on processors that implement the Intel 64 architecture. (Also known as the "x64" architecture, and formerly known as both "EM64T" and "x86-64".)
• There are now "web-based" installers for Windows platforms; the installer will download the needed software components at installation time.
• There are redistributable zip files containing the Windows builds, making it easy to redistribute Python as part of another software package. Please see the documentation regarding Embedded Distribution for more information.

macOS users

• For Python 3.8, we provide one installer: 64-bit-only that works on macOS 10.9 (Mavericks) and later systems.
• Please read the "Important Information" displayed during installation for information about SSL/TLS certificate validation and the running the "Install Certificates.command".

And now for something completely different

Mr Verity (Eric Idle): Can I help you, sir?
Husband: Yes, we'd like a bed, a double bed, and I wondered if you'd got one for about fifty pounds.
Verity: Oh no, I'm afraid not, sir. Our cheapest bed is eight hundred pounds, sir.
Husband and Wife: Eight hundred pounds?
Lambert: Excuse me, sir, but before I go, I ought to have told you that Mr Verity does tend to exaggerate. Every figure he gives you will be ten times too high.
Husband: I see.
Lambert: Otherwise he's perfectly all right.
Husband: I see. Er... your cheapest double bed then is eighty pounds?
Verity: Eight hundred pounds, yes, sir.
Husband: I see. And how wide is it?
Verity: It's sixty feet wide.

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