文档

• bpo-41428 [https://bugs.python.org/issue?@action=redirect&bpo=41428]: Add documentation for PEP 604 [https://peps.python.org/pep-0604/] (Allow writing union types as X | Y).

• bpo-41774 [https://bugs.python.org/issue?@action=redirect&bpo=41774]: In Programming FAQ "Sequences (Tuples/Lists)" section, add "How do you remove multiple items from a list".

• bpo-35293 [https://bugs.python.org/issue?@action=redirect&bpo=35293]: Fix RemovedInSphinx40Warning when building the documentation. Patch by Donghee Na.

• bpo-37149 [https://bugs.python.org/issue?@action=redirect&bpo=37149]: Change Shipman tkinter doc link from archive.org to TkDocs. (The doc has been removed from the NMT server.) The new link responds much faster and includes a short explanatory note.

• bpo-41726 [https://bugs.python.org/issue?@action=redirect&bpo=41726]: Update the refcounts info of PyType_FromModuleAndSpec.

• bpo-41624 [https://bugs.python.org/issue?@action=redirect&bpo=41624]: Fix the signature of typing.Coroutine.

• bpo-40204 [https://bugs.python.org/issue?@action=redirect&bpo=40204]: Enable Sphinx 3.2 c_allow_pre_v3 option and disable c_warn_on_allowed_pre_v3 option to make the documentation compatible with Sphinx 2 and Sphinx 3.

• bpo-41045 [https://bugs.python.org/issue?@action=redirect&bpo=41045]: Add documentation for debug feature of fstrings.

• bpo-41314 [https://bugs.python.org/issue?@action=redirect&bpo=41314]: Changed the release when from __future__ import annotations becomes the default from 4.0 to 3.10 (following a change in PEP 563).

• bpo-40979 [https://bugs.python.org/issue?@action=redirect&bpo=40979]: Refactored typing.rst, arranging more than 70 classes, functions, and decorators into new subsections.

• bpo-40552 [https://bugs.python.org/issue?@action=redirect&bpo=40552]: Fix in tutorial section 4.2. Code snippet is now correct.

• bpo-39883 [https://bugs.python.org/issue?@action=redirect&bpo=39883]: Make code, examples, and recipes in the Python documentation be licensed under the more permissive BSD0 license in addition to the existing Python 2.0 license.

• bpo-37703 [https://bugs.python.org/issue?@action=redirect&bpo=37703]: Updated Documentation to comprehensively elaborate on the behaviour of gather.cancel()

测试

• bpo-41939 [https://bugs.python.org/issue?@action=redirect&bpo=41939]: Fix test_site.test_license_existsaturl(): call urllib.request.urlcleanup() to reset the global urllib.request._opener. Patch by Victor Stinner.

• bpo-41731 [https://bugs.python.org/issue?@action=redirect&bpo=41731]: Make test_cmd_line_script pass with option '-vv'.

• bpo-41602 [https://bugs.python.org/issue?@action=redirect&bpo=41602]: Add tests for SIGINT handling in the runpy module.

• bpo-41521 [https://bugs.python.org/issue?@action=redirect&bpo=41521]: test.support: Rename blacklist parameter of check__all__() to not_exported.

• bpo-41477 [https://bugs.python.org/issue?@action=redirect&bpo=41477]: Make ctypes optional in test_genericalias.

• bpo-41085 [https://bugs.python.org/issue?@action=redirect&bpo=41085]: Fix integer overflow in the array.array.index() method on 64-bit Windows for index larger than 2**31.

• bpo-41069 [https://bugs.python.org/issue?@action=redirect&bpo=41069]: test.support.TESTFN and the current directory for tests when run via test.regrtest contain now nonascii characters if possible.

• bpo-38377 [https://bugs.python.org/issue?@action=redirect&bpo=38377]: On Linux, skip tests using multiprocessing if the current user cannot create a file in devshm/ directory. Add the skip_if_broken_multiprocessing_synchronize() function to the test.support module.

• bpo-41009 [https://bugs.python.org/issue?@action=redirect&bpo=41009]: Fix use of support.require_{linux|mac|freebsd}_version() decorators as class decorator.

• bpo-41003 [https://bugs.python.org/issue?@action=redirect&bpo=41003]: Fix test_copyreg when numpy is installed: test.pickletester now saves/restores warnings filters when importing numpy, to ignore filters installed by numpy.

• bpo-40964 [https://bugs.python.org/issue?@action=redirect&bpo=40964]: Disable remote imaplib tests, host cyrus.andrew.cmu.edu is blocking incoming connections.

• bpo-40927 [https://bugs.python.org/issue?@action=redirect&bpo=40927]: Fix test_binhex when run twice: it now uses import_fresh_module() to ensure that it raises DeprecationWarning each time.

• bpo-17258 [https://bugs.python.org/issue?@action=redirect&bpo=17258]: Skip some multiprocessing tests when MD5 hash digest is blocked.

• bpo-31904 [https://bugs.python.org/issue?@action=redirect&bpo=31904]: Increase LOOPBACK_TIMEOUT to 10 for VxWorks RTOS.

• bpo-38169 [https://bugs.python.org/issue?@action=redirect&bpo=38169]: Increase code coverage for SharedMemory and ShareableList

• bpo-34401 [https://bugs.python.org/issue?@action=redirect&bpo=34401]: Make test_gdb properly run on HP-UX. Patch by Michael Osipov.

构建

• bpo-38249 [https://bugs.python.org/issue?@action=redirect&bpo=38249]: Update Py_UNREACHABLE to use __builtin_unreachable() if only the compiler is able to use it. Patch by Donghee Na.

• bpo-41617 [https://bugs.python.org/issue?@action=redirect&bpo=41617]: Fix pycore_bitutils.h header file to support old clang versions: __builtin_bswap16() is not available in LLVM clang 3.0.

• bpo-40204 [https://bugs.python.org/issue?@action=redirect&bpo=40204]: Pin Sphinx version to 2.3.1 in Doc/Makefile.

• bpo-36020 [https://bugs.python.org/issue?@action=redirect&bpo=36020]: The C99 functions snprintf() and vsnprintf() are now required to build Python.

• bpo-40684 [https://bugs.python.org/issue?@action=redirect&bpo=40684]: make install now uses the PLATLIBDIR variable for the destination lib-dynload/ directory when ./configure --with-platlibdir is used.

• bpo-40683 [https://bugs.python.org/issue?@action=redirect&bpo=40683]: Fixed an issue where the zoneinfo module and its tests were not included when Python is installed with make.

Windows

• bpo-41744 [https://bugs.python.org/issue?@action=redirect&bpo=41744]: Fixes automatic import of props file when using the Nuget package.

• bpo-41627 [https://bugs.python.org/issue?@action=redirect&bpo=41627]: The user site directory for 32-bit now includes a -32 suffix to distinguish it from the 64-bit interpreter's directory.

• bpo-41526 [https://bugs.python.org/issue?@action=redirect&bpo=41526]: Fixed layout of final page of the installer by removing the special thanks to Mark Hammond (with his permission).

• bpo-41492 [https://bugs.python.org/issue?@action=redirect&bpo=41492]: Fixes the description that appears in UAC prompts.

• bpo-40948 [https://bugs.python.org/issue?@action=redirect&bpo=40948]: Improve post-install message to direct people to the "py" command.

• bpo-41412 [https://bugs.python.org/issue?@action=redirect&bpo=41412]: The installer will now fail to install on Windows 7 and Windows 8. Further, the UCRT dependency is now always downloaded on demand.

• bpo-40741 [https://bugs.python.org/issue?@action=redirect&bpo=40741]: Update Windows release to include SQLite 3.32.3.

• bpo-41142 [https://bugs.python.org/issue?@action=redirect&bpo=41142]: msilib now supports creating CAB files with nonASCII file path and adding files with nonASCII file path to them.

• bpo-41074 [https://bugs.python.org/issue?@action=redirect&bpo=41074]: Fixed support of nonASCII names in functions msilib.OpenDatabase() and msilib.init_database() and nonASCII SQL in method msilib.Database.OpenView().

• bpo-41039 [https://bugs.python.org/issue?@action=redirect&bpo=41039]: Stable ABI redirection DLL (python3.dll) now uses #pragma comment(linker) for reexporting.

• bpo-40164 [https://bugs.python.org/issue?@action=redirect&bpo=40164]: Updates Windows OpenSSL to 1.1.1g

• bpo-39631 [https://bugs.python.org/issue?@action=redirect&bpo=39631]: Changes the registered MIME type for .py files on Windows to text/x-python instead of text/plain.

• bpo-40677 [https://bugs.python.org/issue?@action=redirect&bpo=40677]: Manually define IO_REPARSE_TAG_APPEXECLINK in case some old Windows SDK doesn't have it.

• bpo-37556 [https://bugs.python.org/issue?@action=redirect&bpo=37556]: Extend py.exe help to mention overrides via venv, shebang, environmental variables & ini files.

macOS

• bpo-41557 [https://bugs.python.org/issue?@action=redirect&bpo=41557]: Update macOS installer to use SQLite 3.33.0.

• bpo-39580 [https://bugs.python.org/issue?@action=redirect&bpo=39580]: Avoid opening Finder window if running installer from the command line. Patch contributed by Rick Heil.

• bpo-41100 [https://bugs.python.org/issue?@action=redirect&bpo=41100]: Fix configure error when building on macOS 11. Note that the current Python release was released shortly after the first developer preview of macOS 11 (Big Sur); there are other known issues with building and running on the developer preview. Big Sur is expected to be fully supported in a future bugfix release of Python 3.8.x and with 3.9.0.

• bpo-40741 [https://bugs.python.org/issue?@action=redirect&bpo=40741]: Update macOS installer to use SQLite 3.32.3.

• bpo-41005 [https://bugs.python.org/issue?@action=redirect&bpo=41005]: fixed an XDG settings issue not allowing macos to open browser in webbrowser.py

• bpo-40741 [https://bugs.python.org/issue?@action=redirect&bpo=40741]: Update macOS installer to use SQLite 3.32.2.

IDLE

• bpo-41775 [https://bugs.python.org/issue?@action=redirect&bpo=41775]: Use 'IDLE Shell' as shell title

• bpo-35764 [https://bugs.python.org/issue?@action=redirect&bpo=35764]: Rewrite the Calltips doc section.

• bpo-40181 [https://bugs.python.org/issue?@action=redirect&bpo=40181]: In calltips, stop reminding that '/' marks the end of positional-only arguments.

• bpo-41468 [https://bugs.python.org/issue?@action=redirect&bpo=41468]: Improve IDLE run crash error message (which users should never see).

• bpo-41373 [https://bugs.python.org/issue?@action=redirect&bpo=41373]: Save files loaded with no line ending, as when blank, or different line endings, by setting its line ending to the system default. Fix regression in 3.8.4 and 3.9.0b4.

• bpo-41300 [https://bugs.python.org/issue?@action=redirect&bpo=41300]: Save files with nonascii chars. Fix regression released in 3.9.0b4 and 3.8.4.

• bpo-37765 [https://bugs.python.org/issue?@action=redirect&bpo=37765]: Add keywords to module name completion list. Rewrite Completions section of IDLE doc.

• bpo-41152 [https://bugs.python.org/issue?@action=redirect&bpo=41152]: The encoding of stdin, stdout and stderr in IDLE is now always UTF-8.

• bpo-41144 [https://bugs.python.org/issue?@action=redirect&bpo=41144]: Make Open Module open a special module such as os.path.

• bpo-39885 [https://bugs.python.org/issue?@action=redirect&bpo=39885]: Make context menu Cut and Copy work again when right-clicking within a selection.

• bpo-40723 [https://bugs.python.org/issue?@action=redirect&bpo=40723]: Make test_idle pass when run after import.

C API

• bpo-41936 [https://bugs.python.org/issue?@action=redirect&bpo=41936]: Removed undocumented macros Py_ALLOW_RECURSION and Py_END_ALLOW_RECURSION and the recursion_critical field of the PyInterpreterState structure.

• bpo-41692 [https://bugs.python.org/issue?@action=redirect&bpo=41692]: The PyUnicode_InternImmortal() function is now deprecated and will be removed in Python 3.12: use PyUnicode_InternInPlace() instead. Patch by Victor Stinner.

• bpo-41842 [https://bugs.python.org/issue?@action=redirect&bpo=41842]: Add PyCodec_Unregister() function to unregister a codec search function.

• bpo-41834 [https://bugs.python.org/issue?@action=redirect&bpo=41834]: Remove the PyCheckRecursionLimit variable: it has been replaced by ceval.recursion_limit of the PyInterpreterState structure. Patch by Victor Stinner.

• bpo-41689 [https://bugs.python.org/issue?@action=redirect&bpo=41689]: Types created with PyType_FromSpec() now make any signature in their tp_doc slot accessible from __textsignature_.

• bpo-41524 [https://bugs.python.org/issue?@action=redirect&bpo=41524]: Fix bug in PyOS_mystrnicmp and PyOS_mystricmp that incremented pointers beyond the end of a string.

• bpo-41324 [https://bugs.python.org/issue?@action=redirect&bpo=41324]: Add a minimal decimal capsule API. The API supports fast conversions between Decimals up to 38 digits and their triple representation as a C struct.

• bpo-30155 [https://bugs.python.org/issue?@action=redirect&bpo=30155]: Add PyDateTime_DATE_GET_TZINFO() and PyDateTime_TIME_GET_TZINFO() macros for accessing the tzinfo attributes of datetime.datetime and datetime.time objects.

• bpo-40170 [https://bugs.python.org/issue?@action=redirect&bpo=40170]: Revert PyType_HasFeature() change: it reads again directly the PyTypeObject.tp_flags member when the limited C API is not used, rather than always calling PyType_GetFlags() which hides implementation details.

• bpo-41123 [https://bugs.python.org/issue?@action=redirect&bpo=41123]: Remove PyUnicode_AsUnicodeCopy.

• bpo-41123 [https://bugs.python.org/issue?@action=redirect&bpo=41123]: Removed PyLong_FromUnicode().

• bpo-41123 [https://bugs.python.org/issue?@action=redirect&bpo=41123]: Removed PyUnicode_GetMax().

• bpo-41123 [https://bugs.python.org/issue?@action=redirect&bpo=41123]: Removed Py_UNICODE_str* functions manipulating Py_UNICODE* strings.

• bpo-41103 [https://bugs.python.org/issue?@action=redirect&bpo=41103]: PyObject_AsCharBuffer(), PyObject_AsReadBuffer(), PyObject_CheckReadBuffer(), and PyObject_AsWriteBuffer() are removed. Please migrate to new buffer protocol; PyObject_GetBuffer() and PyBuffer_Release().

• bpo-36346 [https://bugs.python.org/issue?@action=redirect&bpo=36346]: Raises DeprecationWarning for PyUnicode_FromUnicode(NULL, size) and PyUnicode_FromStringAndSize(NULL, size) with size > 0.

• bpo-36346 [https://bugs.python.org/issue?@action=redirect&bpo=36346]: Mark Py_UNICODE_COPY, Py_UNICODE_FILL, PyUnicode_WSTR_LENGTH, PyUnicode_FromUnicode, PyUnicode_AsUnicode, and PyUnicode_AsUnicodeAndSize as deprecated in C. Remove Py_UNICODE_MATCH which was deprecated and broken since Python 3.3.

• bpo-40989 [https://bugs.python.org/issue?@action=redirect&bpo=40989]: The PyObject_INIT() and PyObject_INIT_VAR() macros become aliases to, respectively, PyObject_Init() and PyObject_InitVar() functions.

• bpo-36020 [https://bugs.python.org/issue?@action=redirect&bpo=36020]: On Windows, #include "pyerrors.h" no longer defines snprintf and vsnprintf macros.

• bpo-40943 [https://bugs.python.org/issue?@action=redirect&bpo=40943]: The PY_SSIZE_T_CLEAN macro must now be defined to use PyArg_ParseTuple() and Py_BuildValue() formats which use #: es#, et#, s#, u#, y#, z#, U# and Z#. See Parsing arguments and building values and the PEP 353 [https://peps.python.org/pep-0353/].

• bpo-40910 [https://bugs.python.org/issue?@action=redirect&bpo=40910]: Export explicitly the Py_GetArgcArgv() function to the C API and document the function. Previously, it was exported implicitly which no longer works since Python is built with -fvisibility=hidden.

• bpo-40724 [https://bugs.python.org/issue?@action=redirect&bpo=40724]: Allow defining buffer slots in type specs.

• bpo-40679 [https://bugs.python.org/issue?@action=redirect&bpo=40679]: Fix a PyEvalEvalCode() crash if qualname argument is NULL.

• bpo-40839 [https://bugs.python.org/issue?@action=redirect&bpo=40839]: Calling PyDict_GetItem() without GIL held had been allowed for historical reason. It is no longer allowed.

• bpo-40826 [https://bugs.python.org/issue?@action=redirect&bpo=40826]: PyOS_InterruptOccurred() now fails with a fatal error if it is called with the GIL released.

• bpo-40792 [https://bugs.python.org/issue?@action=redirect&bpo=40792]: The result of PyNumber_Index() now always has exact type int. Previously, the result could have been an instance of a subclass of int.

• bpo-39573 [https://bugs.python.org/issue?@action=redirect&bpo=39573]: Convert Py_REFCNT() and Py_SIZE() macros to static inline functions. They cannot be used as l-value anymore: use Py_SET_REFCNT() and Py_SET_SIZE() to set an object reference count and size. This change is backward incompatible on purpose, to prepare the C API for an opaque PyObject structure.

• bpo-40703 [https://bugs.python.org/issue?@action=redirect&bpo=40703]: The PyTypeFromSpec*() functions no longer overwrite the type's "_module" attribute if it is set via "Py_tp_members" or "Py_tp_getset".

• bpo-39583 [https://bugs.python.org/issue?@action=redirect&bpo=39583]: Remove superfluous "extern C" declarations from Include/cpython/*.h.

Python 3.9.0 beta 1

发布日期: 2020-05-19

安全性

• bpo-40501 [https://bugs.python.org/issue?@action=redirect&bpo=40501]: uuid no longer uses ctypes to load libuuid or rpcrt4.dll at runtime.

核心与内置函数

• bpo-40663 [https://bugs.python.org/issue?@action=redirect&bpo=40663]: Correctly generate annotations where parentheses are omitted but required (e.g: Type[(str, int, *other))].

• bpo-40596 [https://bugs.python.org/issue?@action=redirect&bpo=40596]: Fixed str.isidentifier() for non-canonicalized strings containing non-BMP characters on Windows.

• bpo-40593 [https://bugs.python.org/issue?@action=redirect&bpo=40593]: Improved syntax errors for invalid characters in source code.

• bpo-40585 [https://bugs.python.org/issue?@action=redirect&bpo=40585]: Fixed a bug when using codeop.compile_command() that was causing exceptions to be swallowed with the new parser. Patch by Pablo Galindo

• bpo-40566 [https://bugs.python.org/issue?@action=redirect&bpo=40566]: Apply PEP 573 [https://peps.python.org/pep-0573/] to abc.

• bpo-40502 [https://bugs.python.org/issue?@action=redirect&bpo=40502]: Initialize n->n_col_offset. (Patch by Joannah Nanjekye)

• bpo-40527 [https://bugs.python.org/issue?@action=redirect&bpo=40527]: Fix command line argument parsing: no longer write errors multiple times into stderr.

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port errno to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-40523 [https://bugs.python.org/issue?@action=redirect&bpo=40523]: Add pass-throughs for hash() and reversed() to weakref.proxy objects. Patch by Pablo Galindo.

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port syslog to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-40246 [https://bugs.python.org/issue?@action=redirect&bpo=40246]: Reporting a specialised error message for invalid string prefixes, which was introduced in bpo-40246 [https://bugs.python.org/issue?@action=redirect&bpo=40246], is being reverted due to backwards compatibility concerns for strings that immediately follow a reserved keyword without whitespace between them. Constructs like bg="#d00" if clear else"#fca" were failing to parse, which is not an acceptable breakage on such short notice.

• bpo-40417 [https://bugs.python.org/issue?@action=redirect&bpo=40417]: Fix imp module deprecation warning when PyImport_ReloadModule is called. Patch by Robert Rouhani.

• bpo-40408 [https://bugs.python.org/issue?@action=redirect&bpo=40408]: Fixed support of nested type variables in GenericAlias (e.g. list[list[T]]).

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port _stat module to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-29587 [https://bugs.python.org/issue?@action=redirect&bpo=29587]: Enable implicit exception chaining when calling generator.throw().

• bpo-40328 [https://bugs.python.org/issue?@action=redirect&bpo=40328]: Add tools for generating mappings headers for CJKCodecs.

• bpo-40228 [https://bugs.python.org/issue?@action=redirect&bpo=40228]: Setting frame.f_lineno is now robust w.r.t. changes in the source-to-bytecode compiler

• bpo-38880 [https://bugs.python.org/issue?@action=redirect&bpo=38880]: Added the ability to list interpreters associated with channel ends in the internal subinterpreters module.

• bpo-37986 [https://bugs.python.org/issue?@action=redirect&bpo=37986]: Improve performance of PyLong_FromDouble() for values that fit into long.

库

• bpo-40662 [https://bugs.python.org/issue?@action=redirect&bpo=40662]: Fixed ast.get_source_segment() for ast nodes that have incomplete location information. Patch by Irit Katriel.

• bpo-40665 [https://bugs.python.org/issue?@action=redirect&bpo=40665]: Convert bisect to use Argument Clinic.

• bpo-40536 [https://bugs.python.org/issue?@action=redirect&bpo=40536]: Added the available_timezones() function to the zoneinfo module. Patch by Paul Ganssle.

• bpo-40645 [https://bugs.python.org/issue?@action=redirect&bpo=40645]: The hmac.HMAC exposes internal implementation details. The attributes digest_cons, inner, and outer are deprecated and will be removed in the future.

• bpo-40645 [https://bugs.python.org/issue?@action=redirect&bpo=40645]: The internal module _hashlib wraps and exposes OpenSSL's HMAC API. The new code will be used in Python 3.10 after the internal implementation details of the pure Python HMAC module are no longer part of the public API.

• bpo-40637 [https://bugs.python.org/issue?@action=redirect&bpo=40637]: Builtin hash modules can now be disabled or selectively enabled with configure --with-builtin-hashlib-hashes=sha3,blake1 or --without-builtin-hashlib-hashes.

• bpo-37630 [https://bugs.python.org/issue?@action=redirect&bpo=37630]: The hashlib module can now use SHA3 hashes and SHAKE XOF from OpenSSL when available.

• bpo-40479 [https://bugs.python.org/issue?@action=redirect&bpo=40479]: The hashlib now compiles with OpenSSL 3.0.0-alpha2.

• bpo-40257 [https://bugs.python.org/issue?@action=redirect&bpo=40257]: Revert changes to inspect.getdoc().

• bpo-40607 [https://bugs.python.org/issue?@action=redirect&bpo=40607]: When cancelling a task due to timeout, asyncio.wait_for() will now propagate the exception if an error happens during cancellation. Patch by Roman Skurikhin.

• bpo-40612 [https://bugs.python.org/issue?@action=redirect&bpo=40612]: Fix edge cases in SyntaxError formatting. If the offset is <= 0, no caret is printed. If the offset is > line length, the caret is printed pointing just after the last character.

• bpo-40597 [https://bugs.python.org/issue?@action=redirect&bpo=40597]: If text content lines are longer than policy.max_line_length, always use a content-encoding to make sure they are wrapped.

• bpo-40571 [https://bugs.python.org/issue?@action=redirect&bpo=40571]: Added functools.cache() as a simpler, more discoverable way to access the unbounded cache variant of lru_cache(maxsize=None).

• bpo-40503 [https://bugs.python.org/issue?@action=redirect&bpo=40503]: PEP 615 [https://peps.python.org/pep-0615/], the zoneinfo module. Adds support for the IANA time zone database.

• bpo-40397 [https://bugs.python.org/issue?@action=redirect&bpo=40397]: Removed attributes __args__ and __parameters__ from special generic aliases like typing.List (not subscripted).

• bpo-40549 [https://bugs.python.org/issue?@action=redirect&bpo=40549]: Convert posixmodule.c ("posix" or "nt" module) to the multiphase initialization (PEP 489).

• bpo-31033 [https://bugs.python.org/issue?@action=redirect&bpo=31033]: Add a msg argument to Future.cancel() and Task.cancel().

• bpo-40541 [https://bugs.python.org/issue?@action=redirect&bpo=40541]: Added an optional counts parameter to random.sample().

• bpo-40515 [https://bugs.python.org/issue?@action=redirect&bpo=40515]: The ssl and hashlib modules now actively check that OpenSSL is build with thread support. Python 3.7.0 made thread support mandatory and no longer works safely with a no-thread builds.

• bpo-31033 [https://bugs.python.org/issue?@action=redirect&bpo=31033]: When a asyncio.Task is cancelled, the exception traceback now chains all the way back to where the task was first interrupted.

• bpo-40504 [https://bugs.python.org/issue?@action=redirect&bpo=40504]: functools.lru_cache() objects can now be the targets of weakrefs.

• bpo-40559 [https://bugs.python.org/issue?@action=redirect&bpo=40559]: Fix possible memory leak in the C implementation of asyncio.Task.

• bpo-40480 [https://bugs.python.org/issue?@action=redirect&bpo=40480]: fnmatch.fnmatch() could take exponential time in the presence of multiple * pattern characters. This was repaired by generating more elaborate regular expressions to avoid futile backtracking.

• bpo-40495 [https://bugs.python.org/issue?@action=redirect&bpo=40495]: compileall is now able to use hardlinks to prevent duplicates in a case when .pyc files for different optimization levels have the same content.

• bpo-40457 [https://bugs.python.org/issue?@action=redirect&bpo=40457]: The ssl module now support OpenSSL builds without TLS 1.0 and 1.1 methods.

• bpo-40355 [https://bugs.python.org/issue?@action=redirect&bpo=40355]: Improve error reporting in ast.literal_eval() in the presence of malformed ast.Dict nodes instead of silently ignoring any non-conforming elements. Patch by Curtis Bucher.

• bpo-40465 [https://bugs.python.org/issue?@action=redirect&bpo=40465]: Deprecated the optional random argument to random.shuffle().

• bpo-40459 [https://bugs.python.org/issue?@action=redirect&bpo=40459]: platform.win32_ver() now produces correct ptype strings instead of empty strings.

• bpo-39435 [https://bugs.python.org/issue?@action=redirect&bpo=39435]: The first argument of pickle.loads() is now positional-only.

• bpo-39305 [https://bugs.python.org/issue?@action=redirect&bpo=39305]: Update nntplib to merge nntplib.NNTP and nntplib._NNTPBase. Patch by Donghee Na.

• bpo-32494 [https://bugs.python.org/issue?@action=redirect&bpo=32494]: Update dbm.gnu to use gdbm_count if possible when calling len(). Patch by Donghee Na.

• bpo-40453 [https://bugs.python.org/issue?@action=redirect&bpo=40453]: Add isolated=True keyword-only parameter to _xxsubinterpreters.create(). An isolated subinterpreter cannot spawn threads, spawn a child process or call os.fork().

• bpo-40286 [https://bugs.python.org/issue?@action=redirect&bpo=40286]: Remove _random.Random.randbytes(): the C implementation of randbytes(). Implement the method in Python to ease subclassing: randbytes() now directly reuses getrandbits().

• bpo-40394 [https://bugs.python.org/issue?@action=redirect&bpo=40394]: Added default arguments to difflib.SequenceMatcher.find_longest_match().

• bpo-39995 [https://bugs.python.org/issue?@action=redirect&bpo=39995]: Fix a race condition in concurrent.futures._ThreadWakeup: access to _ThreadWakeup is now protected with the shutdown lock.

• bpo-30966 [https://bugs.python.org/issue?@action=redirect&bpo=30966]: Process.shutdown(wait=True) of concurrent.futures now closes explicitly the result queue.

• bpo-30966 [https://bugs.python.org/issue?@action=redirect&bpo=30966]: Add a new close() method to the SimpleQueue class to explicitly close the queue.

• bpo-39966 [https://bugs.python.org/issue?@action=redirect&bpo=39966]: Revert bpo-25597 [https://bugs.python.org/issue?@action=redirect&bpo=25597]. unittest.mock.MagicMock with wraps' set uses default return values for magic methods.

• bpo-39791 [https://bugs.python.org/issue?@action=redirect&bpo=39791]: Added files() function to importlib.resources with support for subdirectories in package data, matching backport in importlib_resources 1.5.

• bpo-40375 [https://bugs.python.org/issue?@action=redirect&bpo=40375]: imaplib.IMAP4.unselect() is added. Patch by Donghee Na.

• bpo-40389 [https://bugs.python.org/issue?@action=redirect&bpo=40389]: repr() now returns typing.Optional[T] when called for typing.Union of two types, one of which is NoneType.

• bpo-40291 [https://bugs.python.org/issue?@action=redirect&bpo=40291]: Add support for CAN_J1939 sockets (available on Linux 5.4+)

• bpo-40273 [https://bugs.python.org/issue?@action=redirect&bpo=40273]: types.MappingProxyType is now reversible.

• bpo-39075 [https://bugs.python.org/issue?@action=redirect&bpo=39075]: The repr for types.SimpleNamespace is now insertion ordered rather than alphabetical.

• bpo-40192 [https://bugs.python.org/issue?@action=redirect&bpo=40192]: On AIX, thread_time() is now implemented with thread_cputime() which has nanosecond resolution, rather than clock_gettime(CLOCK_THREAD_CPUTIME_ID) which has a resolution of 10 milliseconds. Patch by Batuhan Taskaya.

• bpo-40025 [https://bugs.python.org/issue?@action=redirect&bpo=40025]: Raise TypeError when generatenextvalue is defined after members. Patch by Ethan Onstott.

• bpo-39058 [https://bugs.python.org/issue?@action=redirect&bpo=39058]: In the argparse module, the repr for Namespace() and other argument holders now displayed in the order attributes were added. Formerly, it displayed in alphabetical order even though argument order is preserved the user visible parts of the module.

• bpo-24416 [https://bugs.python.org/issue?@action=redirect&bpo=24416]: The isocalendar() methods of datetime.date and datetime.datetime now return a named tuple instead of a tuple.

文档

• bpo-34790 [https://bugs.python.org/issue?@action=redirect&bpo=34790]: Add version of removal for explicit passing of coros to asyncio.wait()'s documentation

• bpo-40561 [https://bugs.python.org/issue?@action=redirect&bpo=40561]: Provide docstrings for webbrowser open functions.

• bpo-40499 [https://bugs.python.org/issue?@action=redirect&bpo=40499]: Mention that asyncio.wait() requires a non-empty set of awaitables.

• bpo-39705 [https://bugs.python.org/issue?@action=redirect&bpo=39705]: Tutorial example for sorted() in the Loop Techniques section is given a better explanation. Also a new example is included to explain sorted()'s basic behavior.

• bpo-39435 [https://bugs.python.org/issue?@action=redirect&bpo=39435]: Fix an incorrect signature for pickle.loads() in the docs

测试

• bpo-40055 [https://bugs.python.org/issue?@action=redirect&bpo=40055]: distutils.tests now saves/restores warnings filters to leave them unchanged. Importing tests imports docutils which imports pkg_resources which adds a warnings filter.

• bpo-40436 [https://bugs.python.org/issue?@action=redirect&bpo=40436]: test_gdb and test.pythoninfo now check gdb command exit code.

构建

• bpo-40653 [https://bugs.python.org/issue?@action=redirect&bpo=40653]: Move dirnameW out of HAVESYMLINK to fix a potential compiling issue.

• bpo-40514 [https://bugs.python.org/issue?@action=redirect&bpo=40514]: Add --with-experimental-isolated-subinterpreters build option to configure: better isolate subinterpreters, experimental build mode.

Windows

• bpo-40650 [https://bugs.python.org/issue?@action=redirect&bpo=40650]: Include winsock2.h in pytime.c for timeval.

• bpo-40458 [https://bugs.python.org/issue?@action=redirect&bpo=40458]: Increase reserved stack space to prevent overflow crash on Windows.

• bpo-39148 [https://bugs.python.org/issue?@action=redirect&bpo=39148]: Add IPv6 support to asyncio datagram endpoints in ProactorEventLoop. Change the raised exception for unknown address families to ValueError as it's not coming from Windows API.

macOS

• bpo-34956 [https://bugs.python.org/issue?@action=redirect&bpo=34956]: When building Python on macOS from source, _tkinter now links with non-system Tcl and Tk frameworks if they are installed in LibraryFrameworks, as had been the case on older releases of macOS. If a macOS SDK is explicitly configured, by using --enable-universalsdk= or -isysroot, only the SDK itself is searched. The default behavior can still be overridden with --with-tcltk-includes and --with-tcltk-libs.

• bpo-35569 [https://bugs.python.org/issue?@action=redirect&bpo=35569]: Expose RFC 3542 IPv6 socket options.

工具/示例

• bpo-40479 [https://bugs.python.org/issue?@action=redirect&bpo=40479]: Update multissltest helper to test with latest OpenSSL 1.0.2, 1.1.0, 1.1.1, and 3.0.0-alpha.

• bpo-40431 [https://bugs.python.org/issue?@action=redirect&bpo=40431]: Fix a syntax typo in turtledemo that now raises a SyntaxError.

• bpo-40163 [https://bugs.python.org/issue?@action=redirect&bpo=40163]: Fix multissltest tool. OpenSSL has changed download URL for old releases. The multissltest tool now tries to download from current and old download URLs.

C API

• bpo-39465 [https://bugs.python.org/issue?@action=redirect&bpo=39465]: Remove the PyUnicodeClearStaticStrings() function from the C API.

• bpo-38787 [https://bugs.python.org/issue?@action=redirect&bpo=38787]: Add PyCFunction_CheckExact() macro for exact type checks now that we allow subtypes of PyCFunction, as well as PyCMethod_CheckExact() and PyCMethod_Check() for the new PyCMethod subtype.

• bpo-40545 [https://bugs.python.org/issue?@action=redirect&bpo=40545]: Declare PyErrGetTopmostException() with PyAPI_FUNC() to properly export the function in the C API. The function remains private (_Py) prefix.

• bpo-40412 [https://bugs.python.org/issue?@action=redirect&bpo=40412]: Nullify inittab_copy during finalization, preventing future interpreter initializations in an embedded situation from crashing. Patch by Gregory Szorc.

• bpo-40429 [https://bugs.python.org/issue?@action=redirect&bpo=40429]: The PyThreadState_GetFrame() function now returns a strong reference to the frame.

• bpo-40428 [https://bugs.python.org/issue?@action=redirect&bpo=40428]: Remove the following functions from the C API. Call PyGC_Collect() explicitly to free all free lists.

  • PyAsyncGen_ClearFreeLists()

  • PyContext_ClearFreeList()

  • PyDict_ClearFreeList()

  • PyFloat_ClearFreeList()

  • PyFrame_ClearFreeList()

  • PyList_ClearFreeList()

  • PySet_ClearFreeList()

  • PyTuple_ClearFreeList()

• bpo-40421 [https://bugs.python.org/issue?@action=redirect&bpo=40421]: New PyFrame_GetBack() function: get the frame next outer frame.

• bpo-40421 [https://bugs.python.org/issue?@action=redirect&bpo=40421]: New PyFrame_GetCode() function: return a borrowed reference to the frame code.

• bpo-40217 [https://bugs.python.org/issue?@action=redirect&bpo=40217]: Ensure that instances of types created with PyType_FromSpecWithBases() will visit its class object when traversing references in the garbage collector (implemented as an extension of the provided tp_traverse). Patch by Pablo Galindo.

• bpo-38787 [https://bugs.python.org/issue?@action=redirect&bpo=38787]: Module C state is now accessible from C-defined heap type methods ( PEP 573 [https://peps.python.org/pep-0573/]). Patch by Marcel Plch and Petr Viktorin.

Python 3.9.0 alpha 6

发布日期: 2020-04-27

安全性

• bpo-40121 [https://bugs.python.org/issue?@action=redirect&bpo=40121]: Fixes audit events raised on creating a new socket.

• bpo-39073 [https://bugs.python.org/issue?@action=redirect&bpo=39073]: Disallow CR or LF in email.headerregistry.Address arguments to guard against header injection attacks.

• bpo-39503 [https://bugs.python.org/issue?@action=redirect&bpo=39503]: CVE 2020-8492 [https://www.cve.org/CVERecord?id=CVE-2020-8492]: The AbstractBasicAuthHandler class of the urllib.request module uses an inefficient regular expression which can be exploited by an attacker to cause a denial of service. Fix the regex to prevent the catastrophic backtracking. Vulnerability reported by Ben Caller and Matt Schwager.

核心与内置函数

• bpo-40313 [https://bugs.python.org/issue?@action=redirect&bpo=40313]: Improve the performance of bytes.hex().

• bpo-40334 [https://bugs.python.org/issue?@action=redirect&bpo=40334]: Switch to a new parser, based on PEG. For more details see PEP 617. To temporarily switch back to the old parser, use -X oldparser or PYTHONOLDPARSER=1. In Python 3.10 we will remove the old parser completely, including the parser module (already deprecated) and anything that depends on it.

• bpo-40267 [https://bugs.python.org/issue?@action=redirect&bpo=40267]: Fix the tokenizer to display the correct error message, when there is a SyntaxError on the last input character and no newline follows. It used to be unexpected EOF while parsing, while it should be invalid syntax.

• bpo-39522 [https://bugs.python.org/issue?@action=redirect&bpo=39522]: Correctly unparse explicit u prefix for strings when postponed evaluation for annotations activated. Patch by Batuhan Taskaya.

• bpo-40246 [https://bugs.python.org/issue?@action=redirect&bpo=40246]: Report a specialized error message, invalid string prefix, when the tokenizer encounters a string with an invalid prefix.

• bpo-40082 [https://bugs.python.org/issue?@action=redirect&bpo=40082]: Fix the signal handler: it now always uses the main interpreter, rather than trying to get the current Python thread state.

• bpo-37388 [https://bugs.python.org/issue?@action=redirect&bpo=37388]: str.encode() and str.decode() no longer check the encoding and errors in development mode or in debug mode during Python finalization. The codecs machinery can no longer work on very late calls to str.encode() and str.decode().

• bpo-40077 [https://bugs.python.org/issue?@action=redirect&bpo=40077]: Fix possible refleaks in _json, memo of PyScannerObject should be traversed.

• bpo-37207 [https://bugs.python.org/issue?@action=redirect&bpo=37207]: Speed up calls to dict() by using the PEP 590 [https://peps.python.org/pep-0590/] vectorcall calling convention.

• bpo-40141 [https://bugs.python.org/issue?@action=redirect&bpo=40141]: Add column and line information to ast.keyword nodes. Patch by Pablo Galindo.

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port resource to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port math to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port _uuid module to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-40077 [https://bugs.python.org/issue?@action=redirect&bpo=40077]: Convert json module to use PyType_FromSpec().

• bpo-40067 [https://bugs.python.org/issue?@action=redirect&bpo=40067]: Improve the error message for multiple star expressions in an assignment. Patch by Furkan Onder

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port _functools module to multiphase initialization (PEP 489). Patch by Paulo Henrique Silva.

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port operator module to multiphase initialization (PEP 489). Patch by Paulo Henrique Silva.

• bpo-20526 [https://bugs.python.org/issue?@action=redirect&bpo=20526]: Fix PyThreadState_Clear(). PyThreadState.frame is a borrowed reference, not a strong reference: PyThreadState_Clear() must not call Py_CLEAR(tstate->frame).

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port time module to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]). Patch by Paulo Henrique Silva.

• bpo-1635741 [https://bugs.python.org/issue?@action=redirect&bpo=1635741]: Port _weakref extension module to multiphase initialization ( PEP 489 [https://peps.python.org/pep-0489/]).

• bpo-40020 [https://bugs.python.org/issue?@action=redirect&bpo=40020]: Fix a leak and subsequent crash in parsetok.c caused by realloc misuse on a rare codepath.

• bpo-39939 [https://bugs.python.org/issue?@action=redirect&bpo=39939]: Added str.removeprefix and str.removesuffix methods and corresponding bytes, bytearray, and collections.UserString methods to remove affixes from a string if present. See PEP 616 [https://peps.python.org/pep-0616/] for a full description. Patch by Dennis Sweeney.

• bpo-39481 [https://bugs.python.org/issue?@action=redirect&bpo=39481]: Implement PEP 585. This supports list[int], tuple[str, …] etc.

• bpo-32894 [https://bugs.python.org/issue?@action=redirect&bpo=32894]: Support unparsing of infinity numbers in postponed annotations. Patch by Batuhan Taşkaya.

• bpo-37207 [https://bugs.python.org/issue?@action=redirect&bpo=37207]: Speed up calls to list() by using the PEP 590 [https://peps.python.org/pep-0590/] vectorcall calling convention. Patch by Mark Shannon.

库

• bpo-40398 [https://bugs.python.org/issue?@action=redirect&bpo=40398]: typing.get_args() now always returns an empty tuple for special generic aliases.

• bpo-40396 [https://bugs.python.org/issue?@action=redirect&bpo=40396]: Functions typing.get_origin(), typing.get_args() and typing.get_type_hints() support now generic aliases like list[int].

• bpo-38061 [https://bugs.python.org/issue?@action=redirect&bpo=38061]: Optimize the subprocess module on FreeBSD using closefrom(). A single close(fd) syscall is cheap, but when sysconf(SCOPEN_MAX) is high, the loop calling close(fd) on each file descriptor can take several milliseconds.

The workaround on FreeBSD to improve performance was to load and mount the fdescfs kernel module, but this is not enabled by default.

Initial patch by Ed Maste (emaste), Conrad Meyer (cem), Kyle Evans (kevans) and Kubilay Kocak (koobs): https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242274

• bpo-38061 [https://bugs.python.org/issue?@action=redirect&bpo=38061]: On FreeBSD, os.closerange(fd_low, fd_high) now calls closefrom(fd_low) if fd_high is greater than or equal to sysconf(SCOPEN_MAX).

Initial patch by Ed Maste (emaste), Conrad Meyer (cem), Kyle Evans (kevans) and Kubilay Kocak (koobs): https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242274

• bpo-40360 [https://bugs.python.org/issue?@action=redirect&bpo=40360]: The lib2to3 module is pending deprecation due to PEP 617 [https://peps.python.org/pep-0617/].

• bpo-40138 [https://bugs.python.org/issue?@action=redirect&bpo=40138]: Fix the Windows implementation of os.waitpid() for exit code larger than INT_MAX >> 8. The exit status is now interpreted as an unsigned number.

• bpo-39942 [https://bugs.python.org/issue?@action=redirect&bpo=39942]: Set "main" as the default module name when "name" is missing in typing.TypeVar. Patch by Weipeng Hong.

• bpo-40275 [https://bugs.python.org/issue?@action=redirect&bpo=40275]: The logging package is now imported lazily in unittest only when the assertLogs() assertion is used.

• bpo-40275 [https://bugs.python.org/issue?@action=redirect&bpo=40275]: The asyncio package is now imported lazily in unittest only when the IsolatedAsyncioTestCase class is used.

• bpo-40330 [https://bugs.python.org/issue?@action=redirect&bpo=40330]: In ShareableList.__setitem__(), check the size of a new string item after encoding it to utf-8, not before.

• bpo-40148 [https://bugs.python.org/issue?@action=redirect&bpo=40148]: Added pathlib.Path.with_stem() to create a new Path with the stem replaced.

• bpo-40325 [https://bugs.python.org/issue?@action=redirect&bpo=40325]: Deprecated support for set objects in random.sample().

• bpo-40257 [https://bugs.python.org/issue?@action=redirect&bpo=40257]: Improved help for the typing module. Docstrings are now shown for all special forms and special generic aliases (like Union and List). Using help() with generic alias like List[int] will show the help for the correspondent concrete type (list in this case).

• bpo-40257 [https://bugs.python.org/issue?@action=redirect&bpo=40257]: inspect.getdoc() no longer returns docstring inherited from the type of the object or from parent class if it is a class if it is not defined in the object itself. In pydoc the documentation string is now shown not only for class, function, method etc, but for any object that has its own __doc__ attribute.

• bpo-40287 [https://bugs.python.org/issue?@action=redirect&bpo=40287]: Fixed SpooledTemporaryFile.seek() to return the position.

• bpo-40290 [https://bugs.python.org/issue?@action=redirect&bpo=40290]: Added zscore() to statistics.NormalDist().

• bpo-40282 [https://bugs.python.org/issue?@action=redirect&bpo=40282]: Allow random.getrandbits(0) to succeed and to return 0.

• bpo-40286 [https://bugs.python.org/issue?@action=redirect&bpo=40286]: Add random.randbytes() function and random.Random.randbytes() method to generate random bytes.

• bpo-40277 [https://bugs.python.org/issue?@action=redirect&bpo=40277]: collections.namedtuple() now provides a human-readable repr for its field accessors.

• bpo-40270 [https://bugs.python.org/issue?@action=redirect&bpo=40270]: The included copy of sqlite3 on Windows is now compiled with the json extension. This allows the use of functions such as json_object.

• bpo-29255 [https://bugs.python.org/issue?@action=redirect&bpo=29255]: Wait in KqueueSelector.select when no fds are registered

• bpo-40260 [https://bugs.python.org/issue?@action=redirect&bpo=40260]: Ensure modulefinder uses io.open_code() and respects coding comments.

• bpo-40234 [https://bugs.python.org/issue?@action=redirect&bpo=40234]: Allow again to spawn daemon threads in subinterpreters (revert change which denied them).

• bpo-39207 [https://bugs.python.org/issue?@action=redirect&bpo=39207]: Workers in ProcessPoolExecutor are now spawned on demand, only when there are no available idle workers to reuse. This optimizes startup overhead and reduces the amount of lost CPU time to idle workers. Patch by Kyle Stanley.

• bpo-40091 [https://bugs.python.org/issue?@action=redirect&bpo=40091]: Fix a hang at fork in the logging module: the new private atfork_reinit() method is now used to reinitialize locks at fork in the child process.

• bpo-40149 [https://bugs.python.org/issue?@action=redirect&bpo=40149]: Implement traverse and clear slots in _abc.abcdata type.

• bpo-40208 [https://bugs.python.org/issue?@action=redirect&bpo=40208]: Remove deprecated symtable.SymbolTable.has_exec().

• bpo-40196 [https://bugs.python.org/issue?@action=redirect&bpo=40196]: Fix a bug in the symtable module that was causing incorrectly report global variables as local. Patch by Pablo Galindo.

• bpo-40190 [https://bugs.python.org/issue?@action=redirect&bpo=40190]: Add support for SCAIX_REALMEM to posix.sysconf().

• bpo-40182 [https://bugs.python.org/issue?@action=redirect&bpo=40182]: Removed the fieldtypes attribute of the typing.NamedTuple class.

• bpo-36517 [https://bugs.python.org/issue?@action=redirect&bpo=36517]: Multiple inheritance with typing.NamedTuple now raises an error instead of silently ignoring other types.

• bpo-40126 [https://bugs.python.org/issue?@action=redirect&bpo=40126]: Fixed reverting multiple patches in unittest.mock. Patcher's __exit__() is now never called if its __enter__() is failed. Returning true from __exit__() silences now the exception.

• bpo-40094 [https://bugs.python.org/issue?@action=redirect&bpo=40094]: CGIHTTPRequestHandler of http.server now logs the CGI script exit code, rather than the CGI script exit status of os.waitpid(). For example, if the script is killed by signal 11, it now logs: "CGI script exit code -11."

• bpo-40108 [https://bugs.python.org/issue?@action=redirect&bpo=40108]: Improve the error message when triying to import a module using runpy and incorrectly using the ".py" extension at the end of the module name. Patch by Pablo Galindo.

• bpo-40094 [https://bugs.python.org/issue?@action=redirect&bpo=40094]: Add os.waitstatus_to_exitcode() function: convert a wait status to an exit code.

• bpo-40089 [https://bugs.python.org/issue?@action=redirect&bpo=40089]: Fix threading._after_fork(): if fork was not called by a thread spawned by threading.Thread, threading._after_fork() now creates a MainThread instance for main_thread, instead of a _DummyThread instance.

• bpo-40089 [https://bugs.python.org/issue?@action=redirect&bpo=40089]: Add a private atfork_reinit() method to _thread.Lock, _thread.RLock, threading.RLock and threading.Condition classes: reinitialize the lock at fork in the child process, reset the lock to the unlocked state. Rename also the private resetinternal_locks() method of threading.Event to atfork_reinit().

• bpo-25780 [https://bugs.python.org/issue?@action=redirect&bpo=25780]: Expose CAN_RAW_JOIN_FILTERS in the socket module.

• bpo-39503 [https://bugs.python.org/issue?@action=redirect&bpo=39503]: AbstractBasicAuthHandler of urllib.request now parses all WWW-Authenticate HTTP headers and accepts multiple challenges per header: use the realm of the first Basic challenge.

• bpo-39812 [https://bugs.python.org/issue?@action=redirect&bpo=39812]: Removed daemon threads from concurrent.futures by adding an internal threading._register_atexit(), which calls registered functions prior to joining all non-daemon threads. This allows for compatibility with subinterpreters, which don't support daemon threads.

• bpo-40050 [https://bugs.python.org/issue?@action=redirect&bpo=40050]: Fix importlib.bootstrapexternal: avoid creating a new winreg builtin module if it's already available in sys.modules, and remove redundant imports.

• bpo-40014 [https://bugs.python.org/issue?@action=redirect&bpo=40014]: Fix os.getgrouplist(): if getgrouplist() function fails because the group list is too small, retry with a larger group list. On failure, the glibc implementation of getgrouplist() sets ngroups to the total number of groups. For other implementations, double the group list size.

• bpo-40017 [https://bugs.python.org/issue?@action=redirect&bpo=40017]: Add time.CLOCK_TAI constant if the operating system support it.

• bpo-40016 [https://bugs.python.org/issue?@action=redirect&bpo=40016]: In re docstring, clarify the relationship between inline and argument compile flags.

• bpo-39953 [https://bugs.python.org/issue?@action=redirect&bpo=39953]: Update internal table of OpenSSL error codes in the ssl module.

• bpo-36144 [https://bugs.python.org/issue?@action=redirect&bpo=36144]: Added PEP 584 [https://peps.python.org/pep-0584/] operators to weakref.WeakValueDictionary.

• bpo-36144 [https://bugs.python.org/issue?@action=redirect&bpo=36144]: Added PEP 584 [https://peps.python.org/pep-0584/] operators to weakref.WeakKeyDictionary.

• bpo-38891 [https://bugs.python.org/issue?@action=redirect&bpo=38891]: Fix linear runtime behaviour of the __getitem__ and __setitem__ methods in multiprocessing.shared_memory.ShareableList. This avoids quadratic performance when iterating a ShareableList. Patch by Thomas Krennwallner.

• bpo-39682 [https://bugs.python.org/issue?@action=redirect&bpo=39682]: Remove undocumented support for closing a pathlib.Path object via its context manager. The context manager magic methods remain, but they are now a no-op, making Path objects immutable.

• bpo-36144 [https://bugs.python.org/issue?@action=redirect&bpo=36144]: Added PEP 584 [https://peps.python.org/pep-0584/] operators (| and |=) to collections.ChainMap.

• bpo-39011 [https://bugs.python.org/issue?@action=redirect&bpo=39011]: Normalization of line endings in ElementTree attributes was removed, as line endings which were replaced by entity numbers should be preserved in original form.

• bpo-38410 [https://bugs.python.org/issue?@action=redirect&bpo=38410]: Properly handle sys.audit() failures in sys.set_asyncgen_hooks().

• bpo-36541 [https://bugs.python.org/issue?@action=redirect&bpo=36541]: lib2to3 now recognizes named assignment expressions (the walrus operator, :=)

• bpo-35967 [https://bugs.python.org/issue?@action=redirect&bpo=35967]: In platform, delay the invocation of 'uname -p' until the processor attribute is requested.

• bpo-35113 [https://bugs.python.org/issue?@action=redirect&bpo=35113]: inspect.getsource() now returns correct source code for inner class with same name as module level class. Decorators are also returned as part of source of the class. Patch by Karthikeyan Singaravelan.

• bpo-33262 [https://bugs.python.org/issue?@action=redirect&bpo=33262]: Deprecate passing None as an argument for shlex.split()'s s parameter. Patch by Zackery Spytz.

• bpo-31758 [https://bugs.python.org/issue?@action=redirect&bpo=31758]: Prevent crashes when using an uninitialized _elementtree.XMLParser object. Patch by Oren Milman.

文档

• bpo-27635 [https://bugs.python.org/issue?@action=redirect&bpo=27635]: The pickle documentation incorrectly claimed that _new_ isn't called by default when unpickling.

• bpo-39879 [https://bugs.python.org/issue?@action=redirect&bpo=39879]: Updated 数据模型 docs to include dict() insertion order preservation. Patch by Furkan Onder and Samy Lahfa.

• bpo-38387 [https://bugs.python.org/issue?@action=redirect&bpo=38387]: Document PyDoc_STRVAR macro in the C-API reference.

• bpo-13743 [https://bugs.python.org/issue?@action=redirect&bpo=13743]: Some methods within xml.dom.minidom.Element class are now better documented.

测试

• bpo-31904 [https://bugs.python.org/issue?@action=redirect&bpo=31904]: Set expected default encoding in test_c_locale_coercion.py for VxWorks RTOS.

• bpo-40162 [https://bugs.python.org/issue?@action=redirect&bpo=40162]: Update Travis CI configuration to OpenSSL 1.1.1f.

• bpo-40146 [https://bugs.python.org/issue?@action=redirect&bpo=40146]: Update OpenSSL to 1.1.1f in Azure Pipelines.

• bpo-40094 [https://bugs.python.org/issue?@action=redirect&bpo=40094]: Add test.support.wait_process() function.

• bpo-40003 [https://bugs.python.org/issue?@action=redirect&bpo=40003]: test.bisect_cmd now copies Python command line options like -O or -W. Moreover, emit a warning if test.bisect_cmd is used with -w/--verbose2 option.

• bpo-39380 [https://bugs.python.org/issue?@action=redirect&bpo=39380]: Add the encoding in ftplib.FTP and ftplib.FTP_TLS to the constructor as keyword-only and change the default from latin-1 to utf-8 to follow RFC 2640 [https://datatracker.ietf.org/doc/html/rfc2640.html].

• bpo-39793 [https://bugs.python.org/issue?@action=redirect&bpo=39793]: Use the same domain when testing make_msgid. Patch by Batuhan Taskaya.

• bpo-1812 [https://bugs.python.org/issue?@action=redirect&bpo=1812]: Fix newline handling in doctest.testfile when loading from a package whose loader has a get_data method. Patch by Peter Donis.

构建

• bpo-38360 [https://bugs.python.org/issue?@action=redirect&bpo=38360]: Support single-argument form of macOS -isysroot flag.

• bpo-40158 [https://bugs.python.org/issue?@action=redirect&bpo=40158]: Fix CPython MSBuild Properties in NuGet Package (build/native/python.props)

• bpo-38527 [https://bugs.python.org/issue?@action=redirect&bpo=38527]: Fix configure check on Solaris for "float word ordering": sometimes, the correct "grep" command was not being used. Patch by Arnon Yaari.

Windows

• bpo-40164 [https://bugs.python.org/issue?@action=redirect&bpo=40164]: Updates Windows to OpenSSL 1.1.1f

• bpo-8901 [https://bugs.python.org/issue?@action=redirect&bpo=8901]: Ignore the Windows registry when the -E option is used.

macOS

• bpo-38329 [https://bugs.python.org/issue?@action=redirect&bpo=38329]: python.org macOS installers now update the Current version symlink of LibraryFrameworks/Python.framework/Versions for 3.9 installs. Previously, Current was only updated for Python 2.x installs. This should make it easier to embed Python 3 into other macOS applications.

• bpo-40164 [https://bugs.python.org/issue?@action=redirect&bpo=40164]: Update macOS installer builds to use OpenSSL 1.1.1g.

IDLE

• bpo-38439 [https://bugs.python.org/issue?@action=redirect&bpo=38439]: Add a 256×256 pixel IDLE icon to support more modern environments. Created by Andrew Clover. Delete the unused macOS idle.icns icon file.

• bpo-38689 [https://bugs.python.org/issue?@action=redirect&bpo=38689]: IDLE will no longer freeze when inspect.signature fails when fetching a calltip.