Python 3.9.6 final 发布

Core and Builtins¶

• bpo-44409: Fix error location information for tokenizer errors raised on initialization of the tokenizer. Patch by Pablo Galindo.
• bpo-43667: Improve Unicode support in non-UTF locales on Oracle Solaris. This issue does not affect other Solaris systems.
• bpo-44168: Fix error message in the parser involving keyword arguments with invalid expressions. Patch by Pablo Galindo
• bpo-44114: Fix incorrect dictkeys_reversed and dictitems_reversed function signatures in C code, which broke webassembly builds.
• bpo-44070: No longer eagerly makes import filenames absolute, except for extension modules, which was introduced in 3.9.5.
• bpo-28146: Fix a confusing error message in str.format().
• bpo-11105: When compiling ast.AST objects with recursive references through compile(), the interpreter doesn’t crash anymore instead it raises a RecursionError.

Library¶

• bpo-44516: Update vendored pip to 21.1.3
• bpo-44482: Fix very unlikely resource leak in glob in alternate Python implementations.
• bpo-44439: Fix in bz2.BZ2File.write() / lzma.LZMAFile.write() methods, when the input data is an object that supports the buffer protocol, the file length may be wrong.
• bpo-44434: _thread.start_new_thread() no longer calls PyThread_exit_thread() explicitly at the thread exit, the call was redundant. On Linux with the glibc, pthread_exit() aborts the whole process if dlopen() fails to open libgcc_s.so file (ex: EMFILE error). Patch by Victor Stinner.
• bpo-44422: The threading.enumerate() function now uses a reentrant lock to prevent a hang on reentrant call. Patch by Victor Stinner.
• bpo-44395: Fix as_string() to pass unixfrom properly. Patch by Dong-hee Na.
• bpo-44342: [Enum] Be more robust in searching for pickle support before making an enum class unpicklable.
• bpo-44356: [Enum] Allow multiple data-type mixins if they are all the same.
• bpo-44254: On Mac, give turtledemo button text a color that works on both light or dark background. Programmers cannot control the latter.
• bpo-44145: hmac computations were not releasing the GIL while calling the OpenSSL HMAC_Update C API (a new feature in 3.9). This unintentionally prevented parallel computation as other hashlib algorithms support.
• bpo-37788: Fix a reference leak when a Thread object is never joined.
• bpo-44061: Fix regression in previous release when calling pkgutil.iter_modules() with a list of pathlib.Path objects
• bpo-36515: The hashlib module no longer does unaligned memory accesses when compiled for ARM platforms.
• bpo-44018: random.seed() no longer mutates bytearray inputs.
• bpo-38352: Add IO, BinaryIO, TextIO, Match, and Pattern to typing.__all__. Patch by Jelle Zijlstra.
• bpo-43972: When http.server.SimpleHTTPRequestHandler sends a 301 (Moved Permanently) for a directory path not ending with /, add a Content-Length: 0 header. This improves the behavior for certain clients.
• bpo-28528: Fix a bug in pdb where checkline() raises AttributeError if it is called after reset().
• bpo-43776: When subprocess.Popen args are provided as a string or as pathlib.Path, the Popen instance repr now shows the right thing.
• bpo-43666: AIX: Lib/_aix_support.get_platform() may fail in an AIX WPAR. The fileset bos.rte appears to have a builddate in both LPAR and WPAR so this fileset is queried rather than bos.mp64. To prevent a similiar situation (no builddate in ODM) a value (9988) sufficient for completing a build is provided. Patch by M Felt.
• bpo-43650: Fix MemoryError in shutil.unpack_archive() which fails inside shutil._unpack_zipfile() on large files. Patch by Igor Bolshakov.
• bpo-43318: Fix a bug where pdb does not always echo cleared breakpoints.
• bpo-43295: datetime.datetime.strptime() now raises ValueError instead of IndexError when matching 'z' with the %z format specifier.
• bpo-37022: pdb now displays exceptions from repr() with its p and pp commands.

Documentation¶

• bpo-40620: Convert examples in tutorial controlflow.rst section 4.3 to be interpreter-demo style.
• bpo-13814: In the Design FAQ, answer “Why don’t generators support the with statement?”
• bpo-44392: Added a new section in the C API documentation for types used in type hinting. Documented Py_GenericAlias and Py_GenericAliasType.
• bpo-38291: Mark typing.io and typing.re as deprecated since Python 3.8 in the documentation. They were never properly supported by type checkers.
• bpo-44322: Document that SyntaxError args have a details tuple and that details are adjusted for errors in f-string field replacement expressions.
• bpo-44195: Corrected references to TraversableResources in docs. There is no TraversableReader.
• bpo-41963: Document that ConfigParser strips off comments when reading configuration files.
• bpo-44072: Correct where in the numeric ABC hierarchy ** support is added, i.e., in numbers.Complex, not numbers.Integral.
• bpo-43558: Add the remark to dataclasses documentation that the __init__() of any base class has to be called in __post_init__(), along with a code example.
• bpo-41621: Document that collections.defaultdict parameter default_factory defaults to None and is positional-only.

Tests¶

• bpo-44287: Fix asyncio test_popen() of test_windows_utils by using a longer timeout. Use military grade battle-tested test.support.SHORT_TIMEOUT timeout rather than a hardcoded timeout of 10 seconds: it’s 30 seconds by default, but it is made longer on slow buildbots. Patch by Victor Stinner.
• bpo-44363: Account for address sanitizer in test_capi. test_capi now passes when run GCC address sanitizer.

Build¶

• bpo-44381: The Windows build now accepts EnableControlFlowGuard set to guard to enable CFG.

Windows¶

• bpo-41299: Fix 16ms jitter when using timeouts in threading, such as with threading.Lock.acquire() or threading.Condition.wait().

macOS¶

• bpo-43568: Relax unnecessarily restrictive MACOSX_DEPLOYMENT_TARGET check when building extension modules for macOS. Patch by Joshua Root.
• bpo-43109: Allow –with-lto configure option to work with Apple-supplied Xcode or Command Line Tools.

IDLE¶

• bpo-40128: Mostly fix completions on macOS when not using tcl/tk 8.6.11 (as with 3.9). The added update_idletask call should be harmless and possibly helpful otherwise.
• bpo-33962: Move the indent space setting from the Font tab to the new Windows tab. Patch by Mark Roseman and Terry Jan Reedy.
• bpo-40468: Split the settings dialog General tab into Windows and Shell/ED tabs. Move help sources, which extend the Help menu, to the Extensions tab. Make space for new options and shorten the dialog. The latter makes the dialog better fit small screens.
• bpo-41611: Avoid uncaught exceptions in AutoCompleteWindow.winconfig_event().
• bpo-41611: Fix IDLE sometimes freezing upon tab-completion on macOS.

Tools/Demos¶

• bpo-44074: Make patchcheck automatically detect the correct base branch name (previously it was hardcoded to ‘master’)

C API¶

• bpo-44441: Py_RunMain() now resets PyImport_Inittab to its initial value at exit. It must be possible to call PyImport_AppendInittab() or PyImport_ExtendInittab() at each Python initialization. Patch by Victor Stinner.
• bpo-42083: Fix crash in PyStructSequence_NewType() when passed NULL in the documentation string slot.

转自 https://docs.python.org/release/3.9.6/whatsnew/changelog.html