bpo-44394: Update the vendored copy of libexpat to 2.4.1 (from 2.2.8) toget the fix for the CVE-2013-0340 “Billion Laughs” vulnerability. Thiscopy is most used on Windows and macOS.

bpo-43124: Made the internalputcmd function insmtplibsanitize input for presence of\r and\n characters to avoid(unlikely) command injection.

bpo-45001: Made email date parsing more robust against malformed input,namely a whitespace-onlyDate: header. Patch by Wouter Bolsterlee.

bpo-38965: Fix test_faulthandler on GCC 10. Use the “volatile” keyword infaulthandler._stack_overflow() to prevent tail call optimization onany compiler, rather than relying on compiler specific pragma.

bpo-44022:http.client now avoids infinitely reading potential HTTPheaders after a100Continue status response from the server.

bpo-43882: The presence of newline or tab characters in parts of a URLcould allow some forms of attacks.

Following the controlling specification for URLs defined by WHATWGurllib.parse() now removes ASCII newlines and tabs from URLs,preventing such attacks.

bpo-42988: CVE-2021-3426: Remove thegetfile feature of thepydoc module which could be abused to read arbitrary files on thedisk (directory traversal vulnerability). Moreover, even source code ofPython modules can contain sensitive data like passwords. Vulnerabilityreported by David Schwörer.

bpo-43285:ftplib no longer trusts the IP address value returnedfrom the server in response to the PASV command by default. This preventsa malicious FTP server from using the response to probe IPv4 address andport combinations on the client network.

Code that requires the former vulnerable behavior may set atrust_server_pasv_ipv4_address attribute on theirftplib.FTPinstances toTrue to re-enable it.

bpo-43075: Fix Regular Expression Denial of Service (ReDoS) vulnerabilityinurllib.request.AbstractBasicAuthHandler. The ReDoS-vulnerableregex has quadratic worst-case complexity and it allows cause a denial ofservice when identifying crafted invalid RFCs. This ReDoS issue is on theclient side and needs remote attackers to control the HTTP server.

bpo-42967: Fix web cache poisoning vulnerability by defaulting the queryargs separator to&, and allowing the user to choose a customseparator.

bpo-42938: Avoid static buffers when computing the repr ofctypes.c_double andctypes.c_longdouble values.

bpo-42103: Prevented potential DoS attack via CPU and RAM exhaustion whenprocessing malformed Apple Property List files in binary format.

bpo-42051: Theplistlib module no longer accepts entitydeclarations in XML plist files to avoid XML vulnerabilities. This shouldnot affect users as entity declarations are not used in regular plistfiles.

bpo-40791: Addvolatile to the accumulator variable inhmac.compare_digest, making constant-time-defeating optimizations lesslikely.

bpo-35560: Fix an assertion error informat() in debug build forfloating point formatting with “n” format, zero padding and small width.Release build is not impacted. Patch by Karthikeyan Singaravelan.

bpo-42103:InvalidFileException andRecursionErrorare now the only errors caused by loading malformed binary Plist file(previously ValueError and TypeError could be raised in some specificcases).

bpo-42794: Update test_nntplib to use offical group name of news.aioe.orgfor testing. Patch by Dong-hee Na.

bpo-41944: Tests for CJK codecs no longer calleval() on contentreceived via HTTP.

bpo-29778: Ensurepython3.dll is loaded from correct locationswhen Python is embedded (CVE-2020-15523).

bpo-41004: CVE-2020-14422: The __hash__() methods ofipaddress.IPv4Interface and ipaddress.IPv6Interface incorrectly generatedconstant hash values of 32 and 128 respectively. This resulted in alwayscausing hash collisions. The fix uses hash() to generate hash values forthe tuple of (address, mask length, network address).

bpo-39603: Prevent http header injection by rejecting control charactersin http.client.putrequest(…).

bpo-41288: Unpickling invalid NEWOBJ_EX opcode with the C implementationraises now UnpicklingError instead of crashing.

bpo-39017: Avoid infinite loop when reading specially crafted TAR filesusing the tarfile module (CVE-2019-20907).

bpo-39073: Disallow CR or LF in email.headerregistry.Address arguments toguard against header injection attacks.

bpo-38576: Disallow control characters in hostnames in http.client,addressing CVE-2019-18348. Such potentially malicious header injectionURLs now cause a InvalidURL to be raised.

bpo-39503: CVE-2020-8492: TheAbstractBasicAuthHandler class of theurllib.request module uses an inefficient regular expression whichcan be exploited by an attacker to cause a denial of service. Fix theregex to prevent the catastrophic backtracking. Vulnerability reported byBen Caller and Matt Schwager.

bpo-39401: Avoid unsafe load ofapi-ms-win-core-path-l1-1-0.dll atstartup on Windows 7.

bpo-39510: Fix segfault inreadinto() method on closed BufferedReader.

bpo-39421: Fix possible crashes when operating with the functions in theheapq module and custom comparison operators.

bpo-39503:AbstractBasicAuthHandler ofurllib.request now parses all WWW-Authenticate HTTP headers andaccepts multiple challenges per header: use the realm of the first Basicchallenge.

bpo-38295: Prevent failure of test_relative_path in test_py_compile onmacOS Catalina.

bpo-38945: Newline characters have been escaped when performing uuencoding to prevent them from overflowing into to content section of theencoded file. This prevents malicious or accidental modification of dataduring the decoding process.

bpo-37228: Due to significant security concerns, thereuse_addressparameter ofasyncio.loop.create_datagram_endpoint() is no longersupported. This is because of the behavior ofSO_REUSEADDR in UDP. Formore details, see the documentation forloop.create_datagram_endpoint(). (Contributed by Kyle Stanley, AntoinePitrou, and Yury Selivanov inbpo-37228.)

bpo-38804: Fixes a ReDoS vulnerability inhttp.cookiejar. Patch byBen Caller.

bpo-38243: Escape the server title ofxmlrpc.server.DocXMLRPCServer when rendering the document page asHTML. (Contributed by Dong-hee Na inbpo-38243.)

bpo-38174: Update vendorized expat library version to 2.2.8, whichresolves CVE-2019-15903.

bpo-37461: Fix an infinite loop when parsing specially crafted emailheaders. Patch by Abhilash Raj.

bpo-34155: Fix parsing of invalid email addresses with more than one@(e.g. a@b@c.com.) to not return the part before 2nd@ as valid emailaddress. Patch by maxking & jpic.

bpo-38216: Allow the rare code that wants to send invalid http requestsfrom thehttp.client library a way to do so. The fixes forbpo-30458led to breakage for some projects that were relying on this ability totest their own behavior in the face of bad requests.

bpo-36564: Fix infinite loop in email header folding logic that would betriggered when an email policy’s max_line_length is not long enough toinclude the required markup and any values in the message. Patch by PaulGanssle

bpo-37437: Update vendorized expat version to 2.2.7.

bpo-34602: Avoid test suite failures on macOS by no longer callingresource.setrlimit to increase the process stack size limit at runtime.The runtime change is no longer needed since the interpreter is beingbuilt with a larger default stack size.

bpo-35907: CVE-2019-9948: Avoid file reading by disallowinglocal-file:// andlocal_file:// URL schemes inURLopener().open() andURLopener().retrieve() ofurllib.request.

bpo-36742: Fixes mishandling of pre-normalization characters inurlsplit().

bpo-30458: Address CVE-2019-9740 by disallowing URL paths with embeddedwhitespace or control characters through into the underlying http clientrequest. Such potentially malicious header injection URLs now cause anhttp.client.InvalidURL exception to be raised.

bpo-36216: Changes urlsplit() to raise ValueError when the URL containscharacters that decompose under IDNA encoding (NFKC-normalization) intocharacters that affect how the URL is parsed.

bpo-33529: Prevent fold function used in email header encoding fromentering infinite loop when there are too many non-ASCII characters in aheader.

bpo-35746: [CVE-2019-5010] Fix a NULL pointer deref in ssl module. Thecert parser did not handle CRL distribution points with empty DP or URIcorrectly. A malicious or buggy certificate can result into segfault.Vulnerability (TALOS-2018-0758) reported by Colin Read and Nicolas Edet ofCisco.

bpo-35121: Don’t send cookies of domain A without Domain attribute todomain B when domain A is a suffix match of domain B while using acookiejar withhttp.cookiejar.DefaultCookiePolicy policy. Patchby Karthikeyan Singaravelan.

bpo-35643: Fixed a SyntaxWarning: invalid escape sequence inModules/_sha3/cleanup.py. Patch by Mickaël Schoentgen.

bpo-35121: Don’t set cookie for a request when the request path is aprefix match of the cookie’s path attribute but doesn’t end with “/”.Patch by Karthikeyan Singaravelan.

bpo-35605: Fix documentation build for sphinx<1.6. Patch by AnthonySottile.

bpo-35564: Explicitly set master_doc variable in conf.py for compliancewith Sphinx 2.0

bpo-36816: Update Lib/test/selfsigned_pythontestdotnet.pem to matchself-signed.pythontest.net’s new TLS certificate.

bpo-35925: Skip specific nntplib and ssl networking tests when they wouldotherwise fail due to a modern OS or distro with a default OpenSSL policyof rejecting connections to servers with weak certificates or disablingTLS below TLSv1.2.

bpo-27313: Avoid test_ttk_guionly ComboboxTest failure with macOS CocoaTk.

bpo-32947: test_ssl fixes for TLS 1.3 and OpenSSL 1.1.1.

bpo-34602: Avoid failures setting macOS stack resource limit withresource.setrlimit. This reverts an earlier fix forbpo-18075 which forceda non-default stack size when building the interpreter executable onmacOS.

bpo-31715: Associate.mjs file extension withapplication/javascript MIME Type.

bpo-35499:makeprofile-opt no longer replacesCFLAGS_NODIST withCFLAGS. It now adds profile-guided optimization (PGO) flags toCFLAGS_NODIST: existingCFLAGS_NODIST flags are kept.

bpo-35257: Avoid leaking the linker flags from Link Time Optimizations(LTO) into distutils when compiling C extensions.

bpo-35259: Conditionally declarePy_FinalizeEx() (new in 3.6)based on Py_LIMITED_API. Patch by Arthur Neufeld.

bpo-34812: The-I command line option (run Python in isolatedmode) is now also copied by themultiprocessing anddistutils modules when spawning child processes. Previously, only-E and-s options (enabled by-I) werecopied.

bpo-34791: The xml.sax and xml.dom.domreg no longer use environmentvariables to override parser implementations whensys.flags.ignore_environment is set by -E or -I arguments.

bpo-35444: Fixed error handling in pickling methods when fail to look upbuiltin “getattr”.

bpo-35436: Fix various issues with memory allocation error handling.Patch by Zackery Spytz.

bpo-35357: Internal attributes’ names of unittest.mock._Call andunittest.mock.MagicProxy (name, parent & from_kall) are now prefixed with_mock_ in order to prevent clashes with widely used object attributes.Fixed minor typo in test function name.

bpo-35372: Fixed the code page decoder for input longer than 2 GiBcontaining undecodable bytes.

bpo-33954: Forstr.format(),float.__format__() andcomplex.__format__() methods for non-ASCII decimal point when usingthe “n” formatter.

bpo-35214: Fixed an out of bounds memory access when parsing a truncatedunicode escape sequence at the end of a string such as'\N'. It wouldread one byte beyond the end of the memory allocation.

bpo-35214: The interpreter and extension modules have had annotationsadded so that they work properly under clang’s Memory Sanitizer. A newconfigure flag –with-memory-sanitizer has been added to make test buildsof this nature easier to perform.

bpo-35193: Fix an off by one error in the bytecode peephole optimizerwhere it could read bytes beyond the end of bounds of an array whenremoving unreachable code. This bug was present in every release of Python3.6 until now.

bpo-29341: Clarify in the docstrings ofos methods that path-likeobjects are also accepted as input parameters.

bpo-35050:socket: Fix off-by-one bug in length check forAF_ALG name and type.

bpo-34974:bytes andbytearray constructors no longerconvert unexpected exceptions (e.g.MemoryError andKeyboardInterrupt) toTypeError.

bpo-34973: Fixed crash inbytes() when thelist argument ismutated while it is iterated.

bpo-34824: Fix a possible null pointer dereference in Modules/_ssl.c.Patch by Zackery Spytz.

bpo-1621: Do not assume signed integer overflow behavior (C undefinedbehavior) when performing set hash table resizing.

bpo-35052: Fix xml.dom.minidom cloneNode() on a document with an entity:pass the correct arguments to the user data handler of an entity.

bpo-35330: When aMock instance was used to wrap an object, ifside_effect is used in one of the mocks of it methods, don’t call theoriginal implementation and return the result of using the side effect thesame way that it is done with return_value.

bpo-34172: Revert the fix for this issue previously released in 3.6.7pending further investigation: Fix a reference issue insidemultiprocessing.Pool that caused the pool to remain alive if it wasdeleted without being closed or terminated explicitly.

bpo-10496:posixpath.expanduser() now returns the inputpathunchanged if theHOME environment variable is not set and the currentuser has no home directory (if the current user identifier doesn’t existin the password database). This change fix thesite module if thecurrent user doesn’t exist in the password database (if the user has nohome directory).

bpo-35310: Fix a bug inselect.select() where, in some cases, thefile descriptor sequences were returned unmodified after a signalinterruption, even though the file descriptors might not be ready yet.select.select() will now always return empty lists if a timeout hasoccurred. Patch by Oran Avraham.

bpo-35380: Enable TCP_NODELAY on Windows for proactor asyncio event loop.

bpo-35371: Fixed possible crash inos.utime() on Windows when passincorrect arguments.

bpo-27903: FixResourceWarning inplatform.dist() on SuSE andCaldera OpenLinux. Patch by Ville Skyttä.

bpo-28604:locale.localeconv() now sets temporarily theLC_CTYPElocale to theLC_MONETARY locale if the two locales are different andmonetary strings are non-ASCII. This temporary change affects otherthreads.

bpo-35277: Update ensurepip to install pip 18.1 and setuptools 40.6.2.

bpo-35226: Recursively check arguments when testing for equality ofunittest.mock.call objects and add note that tracking ofparameters used to create ancestors of mocks inmock_calls is notpossible.

bpo-35189: Modify the following fnctl function to retry if interrupted bya signal (EINTR): flock, lockf, fnctl

bpo-35062: Fix incorrect parsing of_io.IncrementalNewlineDecoder’stranslate argument.

bpo-35079: Improve difflib.SequenceManager.get_matching_blocks doc byadding ‘non-overlapping’ and changing ‘!=’ to ‘<’.

bpo-35017:socketserver.BaseServer.serve_forever() now exitsimmediately if it’sshutdown() method iscalled while it is polling for new events.

bpo-31047: Fixntpath.abspath regression where it didn’t remove atrailing separator on Windows. Patch by Tim Graham.

bpo-34794: Fixed a leak in Tkinter when pass the Python wrapper aroundTcl_Obj back to Tcl/Tk.

bpo-35008: Fixed references leaks when call the__setstate__() methodofxml.etree.ElementTree.Element in the C implementation foralready initialized element.

bpo-23420: Verify the value for the parameter ‘-s’ of the cProfile CLI.Patch by Robert Kuska

bpo-16965: The2to3execfile fixer now opens the filewith mode'rb'. Patch by Zackery Spytz.

bpo-34966:pydoc now supports aliases not only to methods definedin the end class, but also to inherited methods. The docstring is notduplicated for aliases.

bpo-34941: Methodsfind(),findtext() andfindall() of theElement class in thexml.etree.ElementTree module are now ableto find children which are instances ofElement subclasses.

bpo-34936: FixTclError intkinter.Spinbox.selection_element().Patch by Juliette Monsel.

bpo-34900: Fixedunittest.TestCase.debug() when used to call testmethods with subtests. Patch by Bruno Oliveira.

bpo-34866: Addingmax_num_fields tocgi.FieldStorage to make DOSattacks harder by limiting the number ofMiniFieldStorage objectscreated byFieldStorage.

bpo-34738: ZIP files created bydistutils will now include entriesfor directories.

bpo-31177: Fix bug that prevented usingreset_mock on mock instances with deleted attributes

bpo-34604: Fix possible mojibake in the error message ofpwd.getpwnamandgrp.getgrnam using string representation because of invisiblecharacters or trailing whitespaces. Patch by William Grzybowski.

bpo-34574: OrderedDict iterators are not exhausted during picklinganymore. Patch by Sergey Fedoseev.

bpo-34052:sqlite3.Connection.create_aggregate(),sqlite3.Connection.create_function(),sqlite3.Connection.set_authorizer(),sqlite3.Connection.set_progress_handler() methods raises TypeErrorwhen unhashable objects are passed as callable. These methods now don’tpass such objects to SQLite API. Previous behavior could lead tosegfaults. Patch by Sergey Fedoseev.

bpo-29877: compileall: import ProcessPoolExecutor only when needed,preventing hangs on low resource platforms

bpo-22005: Implemented unpickling instances ofdatetime,date andtime pickled by Python 2.encoding='latin1' shouldbe used for successful decoding.

bpo-35089: Remove mention oftyping.io andtyping.re. Their typesshould be imported fromtyping directly.

bpo-35038: Fix the documentation about an unexistingf_restrictedattribute in the frame object. Patch by Stéphane Wirtel

bpo-35035: Rename documentation foremail.utils toemail.utils.rst.

bpo-34967: Use app.add_object_type() instead of the deprecated Sphinxfunction app.description_unit()

bpo-33594: Documentgetargspec,from_function andfrom_builtinas deprecated in their respective docstring, and include version sincedeprecation in DeprecationWarning message.

bpo-32613: Update the faq/windows.html to use the py command from PEP 397instead of python.

bpo-33725: test_multiprocessing_fork may crash on recent versions ofmacOS. Until the issue is resolved, skip the test on macOS.

bpo-35352: Modify test_asyncio to use the certificate set from the testdirectory.

bpo-35317: Fixmktime() overflow error intest_email: runtest_localtime_daylight_true_dst_true() andtest_localtime_daylight_false_dst_true() with a specific timezone.

bpo-21263: After several reports that test_gdb does not work properly onmacOS and since gdb is not shipped by default anymore, test_gdb is nowskipped on macOS when LLVM Clang has been used to compile Python. Patch byLysandros Nikolaou

bpo-34279: regrtest issue a warning when no tests have been executed in aparticular test file. Also, a new final result state is issued if no testhave been executed across all test files. Patch by Pablo Galindo.

bpo-35351: When building Python with clang and LTO, LTO flags are nolonger passed into CFLAGS to build third-party C extensions throughdistutils.

bpo-35139: Fix a compiler error when statically linkingpyexpat inModules/Setup.

bpo-35011: Restores the use of pyexpatns.h to isolate our embedded copy ofthe expat C library so that its symbols do not conflict at link or dynamicloading time with an embedding application or other extension modules withtheir own version of libexpat.

bpo-28015: Have –with-lto works correctly with clang.

bpo-33015: Fix an undefined behaviour in the pthread implementation ofPyThread_start_new_thread(): add a function wrapper to alwaysreturnNULL.

bpo-31625: Stop using ranlib on static libraries. Instead, we assume arsupports the ‘s’ flag.

bpo-31354: Allow –with-lto to be used on all builds, not justmakeprofile-opt.

bpo-35401: Updates Windows build to OpenSSL 1.0.2q

bpo-32890: Fix usage of GetLastError() instead of errno in os.execve() andos.truncate().

bpo-15663: The macOS 10.6+ installer now provides a private copy of Tcl/Tk8.6, like the 10.9+ installer does.

bpo-35402: Update macOS installer to use Tcl/Tk 8.6.9.1. [NOTE: Thischange was reverted for the released python.org 3.6.8 macOS installers dueto regressions found in Tk 8.6.9.1. For now, the installers provideTcl/Tk 8.6.8.]

bpo-35401: Update macOS installer to use OpenSSL 1.0.2q.

bpo-35025: Properly guard the use of theCLOCK_GETTIME et al. macrosintimemodule on macOS.

bpo-24658: On macOS, fix reading from and writing into a file with a sizelarger than 2 GiB.

bpo-35213: Where appropriate, use ‘macOS’ in idlelib.

bpo-34864: On macOS, warn if the system preference “Prefer tabs whenopening documents” is set to “Always”.

bpo-34864: Document two IDLE on MacOS issues. The System Preferences Dock“prefer tabs always” setting disables some IDLE features. Menus are a bitdifferent than as described for Windows and Linux.

bpo-35202: Remove unused imports from lib/idlelib

bpo-33000: Document that IDLE’s shell has no line limit. A program thatruns indefinitely can overfill memory.

bpo-23220: Explain how IDLE’s Shell displays output.

bpo-35099: Improve the doc about IDLE running user code. The section isrenamed from “IDLE – console differences” is renamed “Running user code”.It mostly covers the implications of using custom sys.stdxxx objects.

bpo-35097: Add IDLE doc subsection explaining editor windows. Topicsinclude opening, title and status bar, .py* extension, and running.

bpo-35093: Document the IDLE document viewer in the IDLE doc. Add aparagraph in “Help and preferences”, “Help sources” subsection.

bpo-35088: Update idlelib.help.copy_string docstring. We now use git andbackporting instead of hg and forward merging.

bpo-35087: Update idlelib help files for the current doc build. The mainchange is the elimination of chapter-section numbers.

bpo-34989: python-gdb.py now handles errors on computing the line numberof a Python frame.

bpo-34879: Fix a possible null pointer dereference in bytesobject.c.Patch by Zackery Spytz.

bpo-34320: Fixdict(od) didn’t copy iteration order of OrderedDict.

bpo-34769: Fix for async generators not finalizing when event loop is indebug mode and garbage collector runs in another thread.

bpo-34922: Fixed integer overflow in thedigest()andhexdigest() methods for the SHAKE algorithm inthehashlib module.

bpo-34871: Fix inspect module pollutedsys.modules when parsing__text_signature__ of callable.

bpo-34872: Fix self-cancellation in C implementation of asyncio.Task

bpo-34819: Use a monotonic clock to compute timeouts inExecutor.map() andas_completed(), in order to preventtimeouts from deviating when the system clock is adjusted.

bpo-34521: Usesocket.CMSG_SPACE() to calculate ancillary data sizeinstead ofsocket.CMSG_LEN() inmultiprocessing.reduction.recvfds() asRFC 3542 requires the useof the former for portable applications.

bpo-34282: Fix enum members getting shadowed by parent attributes.

bpo-34172: Fix a reference issue inside multiprocessing.Pool that causedthe pool to remain alive if it was deleted without being closed orterminated explicitly.

bpo-33729: Fixed issues with arguments parsing inhashlib.

bpo-32174: chm document displays non-ASCII charaters properly on some MBCSWindows systems.

bpo-32962: Fixed test_gdb when Python is compiled with flags -mcet-fcf-protection -O0.

bpo-34370: Revert to using the released Tk 8.6.8 with macOS installersinstead of the Tk 8.6.x development snapshot used with 3.7.1rc1 and3.6.7rc1. The snapshot introduced at least one significant regression(bpo-34927).

bpo-34910: Ensure thatPyObject_Print() always returns-1 onerror. Patch by Zackery Spytz.

bpo-17239: The xml.sax and xml.dom.minidom parsers no longer processesexternal entities by default. External DTD and ENTITY declarations nolonger load files or create network connections.

bpo-34623: CVE-2018-14647: The C accelerated _elementtree module nowinitializes hash randomization salt from _Py_HashSecret instead oflibexpat’s default CSPRNG.

bpo-34405: Updated to OpenSSL 1.0.2p for Windows builds.

bpo-33871: Fixed sending the part of the file inos.sendfile() onmacOS. Using thetrailers argument could cause sending more bytes fromthe input file than was specified.

bpo-32533: Fixed thread-safety of error handling in _ssl.

bpo-34735: Fix a memory leak in Modules/timemodule.c. Patch by ZackerySpytz.

bpo-34588: Fix an off-by-one in the recursive call pruning feature oftraceback formatting.

bpo-34527: On FreeBSD, Py_DecodeLocale() and Py_EncodeLocale() now alsoforces the ASCII encoding if the LC_CTYPE locale is “POSIX”, not only ifthe LC_CTYPE locale is “C”.

bpo-34400: Fix undefined behavior in parsetok.c. Patch by Zackery Spytz.

bpo-34377: Update valgrind suppression list to use_PyObject_Free/_PyObject_Realloc instead ofPyObject_Free/PyObject_Realloc.

bpo-24618: Fixed reading invalid memory when create the code object withtoo small varnames tuple or too large argument counts.

bpo-34068: Inio.IOBase.close(), ensure that theclosed attribute is not set with a live exception.Patch by Zackery Spytz and Serhiy Storchaka.

bpo-34080: Fixed a memory leak in the compiler when it raised someuncommon errors during tokenizing.

bpo-34066: Disabled interruption by Ctrl-C between callingopen() andentering awith block inwithopen().

bpo-33956: Update vendored Expat library copy to version 2.2.5.

bpo-24596: Decref the module object inPyRun_SimpleFileExFlags()before callingPyErr_Print(). Patch by Zackery Spytz.

bpo-33451: Close directly executed pyc files before callingPyEval_EvalCode().

bpo-33312: Fixed clang ubsan (undefined behavior sanitizer) warnings indictobject.c by adjusting how the internal struct _dictkeysobject sharedkeys structure is declared.

bpo-25750: Fix rare Python crash due to bad refcounting intype_getattro() if a descriptor deletes itself from the class. Patchby Jeroen Demeyer.

bpo-25862: Fix assertion failures in thetell() method ofio.TextIOWrapper. Patch by Zackery Spytz.

bpo-34670: Add SSLContext.post_handshake_auth andSSLSocket.verify_client_post_handshake for TLS 1.3’s post handshakeauthentication feature.

bpo-34652: Ensureos.lchmod() is never defined on Linux.

bpo-34625: Update vendorized expat library version to 2.2.6.

bpo-32270: The subprocess module no longer mistakenly closes redirectedfds even when they were in pass_fds when outside of the default {0, 1, 2}set.

bpo-34610: Fixed iterator ofmultiprocessing.managers.DictProxy.

bpo-34421: Fix distutils logging for non-ASCII strings. This causedinstallation issues on Windows.

bpo-34604: Fix possible mojibake in the error message ofpwd.getpwnamandgrp.getgrnam. Patch by William Grzybowski.

bpo-34530:distutils.spawn.find_executable() now falls back onos.defpath if thePATH environment variable is not set.

bpo-34563: On Windows, fix multiprocessing.Connection for very large read:fix _winapi.PeekNamedPipe() and _winapi.ReadFile() for read larger thanINT_MAX (usually 2^31-1).

bpo-13312: Avoids a possible integer underflow (undefined behavior) in thetime module’s year handling code when passed a very low negative yearvalue.

bpo-34472: Improved compatibility for streamed files inzipfile.Previously an optional signature was not being written and certain ZIPapplications were not supported. Patch by Silas Sewell.

bpo-6700: Fix inspect.getsourcelines for module level frames/tracebacks.Patch by Vladimir Matveev.

bpo-32947: Add OP_ENABLE_MIDDLEBOX_COMPAT and test workaround for TLSv1.3for future compatibility with OpenSSL 1.1.1.

bpo-34341: Appending to the ZIP archive with the ZIP64 extension no longergrows the size of extra fields of existing entries.

bpo-18540: Theimaplib.IMAP4 andimaplib.IMAP4_SSLclasses now resolve to the local host IP correctly when the default valueofhost parameter ('') is used.

bpo-34246:smtplib.SMTP.send_message() no longer modifies thecontent of themail_options argument. Patch by Pablo S. Blum de Aguiar.

bpo-31047: Fixntpath.abspath for invalid paths on windows. Patch byFranz Woellert.

bpo-34263: asyncio’s event loop will not pass timeouts longer than one dayto epoll/select etc.

bpo-32215: Fix performance regression insqlite3 when a DMLstatement appeared in a different line than the rest of the SQL query.

bpo-19891: Ignore errors caused by missing / non-writable homedir whilewriting history during exit of an interactive session. Patch by AnthonySottile.

bpo-940286: pydoc’sHelper.showtopic() method now prints the crossreferences of a topic correctly.

bpo-34164:base64.b32decode() could raise UnboundLocalError orOverflowError for incorrect padding. Now it always raisesbase64.Error in these cases.

bpo-33967: functools.singledispatch now raises TypeError instead ofIndexError when no positional arguments are passed.

bpo-34054: The multiprocessing module now uses the monotonic clocktime.monotonic() instead of the system clocktime.time() toimplement timeout.

bpo-34010: Fixed a performance regression for reading streams withtarfile. The buffered read should use a list, instead of appending to abytes object.

bpo-34019: webbrowser: Correct the arguments passed to Opera Browser whenopening a new URL using thewebbrowser module. Patch by Bumsik Kim.

bpo-33978: Closed existing logging handlers before reconfiguration viafileConfig and dictConfig. Patch by Karthikeyan Singaravelan.

bpo-14117: Make minor tweaks to turtledemo. The ‘wikipedia’ example is now‘rosette’, decribing what it draws. The ‘penrose’ print output isreduced. The’1024’ output of ‘tree’ is eliminated.

bpo-33974: Fixed passing lists and tuples of strings containing specialcharacters",\,{,} and\n as options tottk widgets.

bpo-27500: Fix getaddrinfo to resolve IPv6 addresses correctly.

bpo-24567: Improve random.choices() to handle subnormal input weights thatcould occasionally trigger an IndexError.

bpo-33871: Fixed integer overflow inos.readv() andos.writev() and inos.sendfile() withheaders ortrailersarguments (on BSD-based OSes and macOS).

bpo-33899: Tokenize module now implicitly emits a NEWLINE when providedwith input that does not have a trailing new line. This behavior nowmatches what the C tokenizer does internally. Contributed by Ammar Askar.

bpo-33916: bz2 and lzma: When Decompressor.__init__() is called twice,free the old lock to not leak memory.

bpo-32568: Make select.epoll() and its documentation consistent regardingsizehint andflags.

bpo-33663: Convert content length to string before putting to header.

bpo-26544: Fixed implementation ofplatform.libc_ver(). It almostalways returned version ‘2.9’ for glibc.

bpo-27397: Make email module properly handle invalid-length base64strings.

bpo-33476: Fix _header_value_parser.py when address group is missing final‘;’. Contributed by Enrique Perez-Terron

bpo-33570: Change TLS 1.3 cipher suite settings for compatibility withOpenSSL 1.1.1-pre6 and newer. OpenSSL 1.1.1 will have TLS 1.3 cipersenabled by default.

bpo-33365: Print the header values besides the header keys instead justthe header keys ifdebuglevel is set to >0 inhttp.client. Patchby Marco Strigl.

bpo-33336:imaplib now allowsMOVE command inIMAP4.uid() (RFC6851: IMAP MOVE Extension) and potentially as a name of supported methodofIMAP4 object.

bpo-32356: asyncio.transport.resume_reading() and pause_reading() are nowidempotent.

bpo-31608: Raise aTypeError instead of crashing if acollections.deque subclass returns a non-deque from__new__. Patchby Oren Milman.

bpo-29456: Fix bugs in hangul normalization: u1176, u11a7 and u11c3

bpo-28617: Fixed info in the stdtypes docs concerning the types thatsupport membership tests.

bpo-34065: Fix wrongly written basicConfig documentation markup syntax

bpo-33847: Add ‘@’ operator entry to index.

bpo-25041: DocumentAF_PACKET in thesocket module.

bpo-34587: test_socket: Remove RDSTest.testCongestion(). The test tries tofill the receiver’s socket buffer and expects an error. But the RDSprotocol doesn’t require that. Moreover, the Linux implementation of RDSexpects that the producer of the messages reduces its rate, it’s not therole of the receiver to trigger an error. The test fails on Fedora 28 bydesign, so just remove it.

bpo-34661: Fix test_shutil if unzip doesn’t support -t.

bpo-34200: Fixed non-deterministic flakiness of test_pkg by not using thescary test.support.module_cleanup() logic to save and restore sys.modulescontents between test cases.

bpo-34594: Fix usage of hardcodederrno values in the tests.

bpo-34542: Use 3072 RSA keys and SHA-256 signature for test certs andkeys.

bpo-34391: Fix ftplib test for TLS 1.3 by reading from data socket.

bpo-34399: Update all RSA keys and DH params to use at least 2048 bits.

bpo-33746: Fix test_unittest when run in verbose mode.

bpo-33901: Fix test_dbm_gnu on macOS with gdbm 1.15: add a larger value tomake sure that the file size changes.

bpo-33873: Fix a bug inregrtest that caused an extra test to run if–huntrleaks/-R was used. Exit with error in case that invalid parametersare specified to –huntrleaks/-R (at least one warmup run and onerepetition must be used).

bpo-32663: Making sure theSMTPUTF8SimTests class of tests gets run intest_smtplib.py.

bpo-34710: Fixed SSL module build with OpenSSL & pedantic CFLAGS.

bpo-34582: Add JUnit XML output for regression tests and update AzureDevOps builds.

bpo-34121: Fix detection of C11 atomic support on clang.

bpo-30345: Add -g to LDFLAGS when compiling with LTO to get debug symbols.

bpo-34770: Fix a possible null pointer dereference in pyshellext.cpp.

bpo-34603: Fix returning structs from functions produced by MSVC

bpo-34225: Ensure INCLUDE and LIB directories do not end with a backslash.

bpo-34006: Revert line length limit for Windows help docs. The line-lengthlimit is not needed because the pages appear in a separate app rather thanon a browser tab. It can also interact badly with the DPI setting.

bpo-31546: Restore running PyOS_InputHook while waiting for user input atthe prompt. The restores integration of interactive GUI windows (such asMatplotlib figures) with the prompt on Windows.

bpo-30237: Output error when ReadConsole is canceled byCancelSynchronousIo instead of crashing.

bpo-29097: Fix bug wheredatetime.fromtimestamp() erronously throwsanOSError on Windows for values between 0 and 86400. Patch byAmmar Askar.

bpo-34370: Have macOS 10.9+ installer builds for 3.7.1rc and 3.6.7rc use adevelopment snapshot of Tk 8.6 (post-8.6.8) to mitigate certain scrollerissues seen with IDLE and tkinter apps.

bpo-34405: Update to OpenSSL 1.0.2p for macOS installer builds.

bpo-31903: In_scproxy, drop the GIL when calling intoSystemConfiguration to avoid deadlocks.

bpo-34548: Use configured color theme for read-only text views.

bpo-1529353: Enable “squeezing” of long outputs in the shell, to avoidperformance degradation and to clean up the history without losing it.Squeezed outputs may be copied, viewed in a separate window, and“unsqueezed”.

bpo-34047: Fixed mousewheel scrolling direction on macOS.

bpo-34275: Make IDLE calltips always visible on Mac. Some MacOS-tkcombinations need .update_idletasks(). Patch by Kevin Walzer.

bpo-34120: Fix unresponsiveness after closing certain windows and dialogs.

bpo-33975: Avoid small type when running htests. Since part of the purposeof human-viewed tests is to determine that widgets look right, it isimportant that they look the same for testing as when running IDLE.

bpo-33905: Add test for idlelib.stackview.StackBrowser.

bpo-33924: Change mainmenu.menudefs key ‘windows’ to ‘window’. Every othermenudef key is lowercase version of main menu entry.

bpo-33906: Rename idlelib.windows as window Match Window on the main menuand remove last plural module name.

bpo-33917: Fix and document idlelib/idle_test/template.py. The revisedfile compiles, runs, and tests OK. idle_test/README.txt explains how touse it to create new IDLE test files.

bpo-33904: IDLE: In rstrip, rename class RstripExtension as Rstrip

bpo-33907: For consistency and clarity, rename an IDLE module and classes.Module calltips and its class CallTips are now calltip and Calltip. Inmodule calltip_w, class CallTip is now CalltipWindow.

bpo-33856: Add “help” in the welcome message of IDLE

bpo-33839: IDLE: refactor ToolTip and CallTip and add documentation andtests

bpo-33855: Minimally test all IDLE modules. Add missing files, importmodule, instantiate classes, and check coverage. Check existing files.

bpo-32962: python-gdb now catchesUnicodeDecodeError exceptions whencallingstring().

bpo-32962: python-gdb now catches ValueError on read_var(): when Pythonhas no debug symbols for example.

bpo-23927: FixedSystemError inPyArg_ParseTupleAndKeywords() when thew* format unit is usedfor optional parameter.

bpo-33786: Fix asynchronous generators to handle GeneratorExit in athrow()correctly

bpo-30654: Fixed reset of the SIGINT handler to SIG_DFL on interpretershutdown even when there was a custom handler set previously. Patch byPhilipp Kerling.

bpo-33622: Fixed a leak when the garbage collector fails to add an objectwith the__del__ method or referenced by it into thegc.garbage list.PyGC_Collect() can now be called when anexception is set and preserves it.

bpo-31849: Fix signed/unsigned comparison warning in pyhash.c.

bpo-33391: Fix a leak in set_symmetric_difference().

bpo-28055: Fix unaligned accesses in siphash24(). Patch by Rolf Eike Beer.

bpo-33231: Fix potential memory leak innormalizestring().

bpo-29922: Improved error messages in ‘async with’ when__aenter__()or__aexit__() return non-awaitable object.

bpo-33199: Fixma_version_tag in dict implementation is uninitializedwhen copying from key-sharing dict.

bpo-33041: Fixed jumping when the function contains anasyncfor loop.

bpo-32282: Fix an unnecessary ifdef in the include of VersionHelpers.h insocketmodule on Windows.

bpo-21983: Fix a crash inctypes.cast() in case the type argument is actypes structured data type. Patch by Eryk Sun and Oren Milman.

bpo-30167: Prevent site.main() exception if PYTHONSTARTUP is set. Patch bySteve Weber.

bpo-33812: Datetime instance d with non-None tzinfo, but withd.tzinfo.utcoffset(d) returning None is now treated as naive by theastimezone() method.

bpo-30805: Avoid race condition with debug logging

bpo-33767: The concatenation (+) and repetition (*) sequenceoperations now raiseTypeError instead ofSystemError whenperformed onmmap.mmap objects. Patch by Zackery Spytz.

bpo-32684: Fix gather to propagate cancellation of itself even withreturn_exceptions.

bpo-33674: Fix a race condition in SSLProtocol.connection_made() ofasyncio.sslproto: start immediately the handshake instead of usingcall_soon(). Previously, data_received() could be called before thehandshake started, causing the handshake to hang or fail.

bpo-31647: Fixed bug where calling write_eof() on a_SelectorSocketTransport after it’s already closed raises AttributeError.

bpo-33672: Fix Task.__repr__ crash with Cython’s bogus coroutines

bpo-33469: Fix RuntimeError after closing loop that used run_in_executor

bpo-11874: Use a better regex when breaking usage into wrappable parts.Avoids bogus assertion errors from custom metavar strings.

bpo-30877: Fixed a bug in the Python implementation of the JSON decoderthat prevented the cache of parsed strings from clearing after finishingthe decoding. Based on patch by c-fos.

bpo-33548: tempfile._candidate_tempdir_list should consider common TEMPlocations

bpo-33542: Preventuuid.get_node from using a DUID instead of a MAC onWindows. Patch by Zvi Effron

bpo-26819: Fix race condition withReadTransport.resume_reading inWindows proactor event loop.

bpo-28556: Minor fixes in typing module: add annotations toNamedTuple.__new__, pass*args and**kwds inGeneric.__new__. Original PRs by Paulius Šarka and Chad Dombrova.

bpo-20087: Updated alias mapping with glibc 2.27 supported locales.

bpo-33422: Fix trailing quotation marks getting deleted when looking upbyte/string literals on pydoc. Patch by Andrés Delfino.

bpo-33197: Update error message when constructing invalidinspect.Parameters Patch by Dong-hee Na.

bpo-33383: Fixed crash in the get() method of thedbm.ndbm databaseobject when it is called with a single argument.

bpo-33329: Fix multiprocessing regression on newer glibcs

bpo-991266: Fix quoting of theComment attribute ofhttp.cookies.SimpleCookie.

bpo-33131: Upgrade bundled version of pip to 10.0.1.

bpo-33308: Fixed a crash in theparser module when converting an STobject to a tree of tuples or lists withline_info=False andcol_info=True.

bpo-33263: Fix FD leak in_SelectorSocketTransport Patch by VladStarostin.

bpo-33256: Fix display of<module> call in the html produced bycgitb.html(). Patch by Stéphane Blondon.

bpo-33203:random.Random.choice() now raisesIndexError for emptysequences consistently even when called from subclasses without agetrandbits() implementation.

bpo-33224: Update difflib.mdiff() for PEP 479. Convert an uncaughtStopIteration in a generator into a return-statement.

bpo-33209: End framing at the end of C implementation ofpickle.Pickler.dump().

bpo-32861: The urllib.robotparser’s__str__ representation nowincludes wildcard entries and the “Crawl-delay” and “Request-rate” fields.Patch by Michael Lazar.

bpo-33096: Allow ttk.Treeview.insert to insert iid that has a falseboolean value. Note iid=0 and iid=False would be same. Patch by GarvitKhatri.

bpo-33127: The ssl module now compiles with LibreSSL 2.7.1.

bpo-33021: Release the GIL during fstat() calls, avoiding hang of allthreads when calling mmap.mmap(), os.urandom(), and random.seed(). Patchby Nir Soffer.

bpo-27683: Fix a regression inipaddress that result ofhosts() is empty when the network is constructed by a tuplecontaining an integer mask and only 1 bit left for addresses.

bpo-32844: Fix wrong redirection of a low descriptor (0 or 1) to stderr insubprocess if another low descriptor is closed.

bpo-31908: Fix output of cover files fortrace module command-linetool. Previously emitted cover files only when--missing option wasused. Patch by Michael Selik.

bpo-31457: If nested log adapters are used, the innerprocess()methods are no longer omitted.

bpo-16865: Support arrays >=2GiB inctypes. Patch by Segev Finer.

bpo-31238: pydoc: the stop() method of the private ServerThread class nowwaits until DocServer.serve_until_quit() completes and then explicitlysets its docserver attribute to None to break a reference cycle.

bpo-33503: Fix broken pypi link

bpo-33421: Add missing documentation fortyping.AsyncContextManager.

bpo-33378: Add Korean language switcher forhttps://docs.python.org/3/

bpo-33276: Clarify that the__path__ attribute on modules cannot bejust any value.

bpo-33201: Modernize documentation for writing C extension types.

bpo-33195: DeprecatePy_UNICODE usage inc-api/arg document.Py_UNICODE related APIs are deprecated since Python 3.3, but it ismissed in the document.

bpo-33126: Document PyBuffer_ToContiguous().

bpo-27212: Modify documentation for theislice() recipe to consumeinitial values up to the start index.

bpo-28247: Updatezipapp documentation to describe how to makestandalone applications.

bpo-18802: Documentation changes for ipaddress. Patch by Jon Foster andBerker Peksag.

bpo-27428: Update documentation to clarify thatWindowsRegistryFinderimplementsMetaPathFinder. (Patch by Himanshu Lakhara)

bpo-8243: Add a note about curses.addch and curses.addstr exceptionbehavior when writing outside a window, or pad.

bpo-31432: Clarify meaning of CERT_NONE, CERT_OPTIONAL, and CERT_REQUIREDflags for ssl.SSLContext.verify_mode.

bpo-33655: Ignore test_posix_fallocate failures on BSD platforms thatmight be due to running on ZFS.

bpo-19417: Add test_bdb.py.

bpo-5755: Move-Wstrict-prototypes option toCFLAGS_NODIST fromOPT. This option emitted annoying warnings when building extensionmodules written in C++.

bpo-33614: Ensures module definition files for the stable ABI on Windowsare correctly regenerated.

bpo-33522: Enable CI builds on Visual Studio Team Services athttps://python.visualstudio.com/cpython

bpo-33012: Add-Wno-cast-function-type for gcc 8 for silencingwarnings about function casts like casting to PyCFunction in methoddefinition lists.

bpo-33394: Enable the verbose build for extension modules, when GNU makeis passed macros on the command line.

bpo-33184: Update Windows installer to OpenSSL 1.0.2o.

bpo-33184: Update macOS installer build to use OpenSSL 1.0.2o.

bpo-33656: On Windows, add API call saying that tk scales for DPI. OnWindows 8.1+ or 10, with DPI compatibility properties of the Python binaryunchanged, and a monitor resolution greater than 96 DPI, this should maketext and lines sharper. It should otherwise have no effect.

bpo-33768: Clicking on a context line moves that line to the top of theeditor window.

bpo-33763: IDLE: Use read-only text widget for code context instead oflabel widget.

bpo-33664: Scroll IDLE editor text by lines. Previously, the mouse wheeland scrollbar slider moved text by a fixed number of pixels, resulting inpartial lines at the top of the editor box. The change also applies tothe shell and grep output windows, but not to read-only text views.

bpo-33679: Enable theme-specific color configuration for Code Context. Usethe Highlights tab to see the setting for built-in themes or add settingsto custom themes.

bpo-33642: Display up to maxlines non-blank lines for Code Context. Ifthere is no current context, show a single blank line.

bpo-33628: IDLE: Cleanup codecontext.py and its test.

bpo-33564: IDLE’s code context now recognizes async as a block opener.

bpo-29706: IDLE now colors async and await as keywords in 3.6. They becomefull keywords in 3.7.

bpo-21474: Update word/identifier definition from ascii to unicode. Intext and entry boxes, this affects selection by double-click, movementleft/right by control-left/right, and deletion left/right bycontrol-BACKSPACE/DEL.

bpo-33204: IDLE: consistently color invalid string prefixes. A ‘u’ stringprefix cannot be paired with either ‘r’ or ‘f’. Consistently color as muchof the prefix, starting at the right, as is valid. Revise and extendcolorizer test.

bpo-32831: Add docstrings and tests for codecontext.

bpo-33189:pygettext.py now recognizes only literal strings asdocstrings and translatable strings, and rejects bytes literals andf-string expressions.

bpo-31920: Fixed handling directories as arguments in thepygettextscript. Based on patch by Oleg Krasnikov.

bpo-29673: Fix pystackv and pystack gdbinit macros.

bpo-32885: Add an-n flag forTools/scripts/pathfix.py to disableautomatic backup creation (files with~ suffix).

bpo-31583: Fix 2to3 for using with –add-suffix option but without–output-dir option for relative path to files in current directory.

bpo-32374: Document that m_traverse for multi-phase initialized modulescan be called with m_state=NULL, and add a sanity check

bpo-32872: Avoid regrtest compatibility issue with namespace packages.

bpo-33163: Upgrade pip to 9.0.3 and setuptools to v39.0.1.

bpo-33001: Minimal fix to prevent buffer overrun in os.symlink on Windows

bpo-32981: Regexes in difflib and poplib were vulnerable to catastrophicbacktracking. These regexes formed potential DOS vectors (REDOS). Theyhave been refactored. This resolves CVE-2018-1060 and CVE-2018-1061. Patchby Jamie Davis.

bpo-33026: Fixed jumping out of “with” block by setting f_lineno.

bpo-17288: Prevent jumps from ‘return’ and ‘exception’ trace events.

bpo-32889: Update Valgrind suppression list to account for the rename ofPy_ADDRESS_IN_RANG toaddress_in_range.

bpo-32650: Pdb and other debuggers dependent on bdb.py will correctly stepover (next command) native coroutines. Patch by Pablo Galindo.

bpo-32685: Improve suggestion when the Python 2 form of print statement iseither present on the same line as the header of a compound statement orelse terminated by a semi-colon instead of a newline. Patch by NitishChandra.

bpo-32583: Fix possible crashing in builtin Unicode decoders caused bywrite out-of-bound errors when using customized decode error handlers.

bpo-26163: Improved frozenset() hash to create more distinct hash valueswhen faced with datasets containing many similar values.

bpo-27169: The__debug__ constant is now optimized out at compiletime. This fixes alsobpo-22091.

bpo-32329:sys.flags.hash_randomization is now properly set to 0 whenhash randomization is turned off byPYTHONHASHSEED=0.

bpo-30416: The optimizer is now protected from spending much time doingcomplex calculations and consuming much memory for creating largeconstants in constant folding.

bpo-18533:repr() on a dict containing its ownvalues() oritems() no longer raisesRecursionError; OrderedDict similarly.Instead, use..., as for other recursive structures. Patch by BenNorth.

bpo-32028: Leading whitespace is now correctly ignored when generatingsuggestions for converting Py2 print statements to Py3 builtin printfunction calls. Patch by Sanyam Khurana.

bpo-32137: The repr of deeply nested dict now raises a RecursionErrorinstead of crashing due to a stack overflow.

bpo-33064: lib2to3 now properly supports trailing commas after*argsand**kwargs in function signatures.

bpo-31804: Avoid failing in multiprocessing.Process if the standardstreams are closed or None at exit.

bpo-33037: Skip sending/receiving data after SSL transport closing.

bpo-30353: Fix ctypes pass-by-value for structs on 64-bit Cygwin/MinGW.

bpo-33009: Fix inspect.signature() for single-parameter partialmethods.

bpo-32969: Expose several missing constants in zlib and fix correspondingdocumentation.

bpo-32713: Fixed tarfile.itn handling of out-of-bounds float values. Patchby Joffrey Fuhrer.

bpo-30622: The ssl module now detects missing NPN support in LibreSSL.

bpo-32922: dbm.open() now encodes filename with the filesystem encodingrather than default encoding.

bpo-32859: Inos.dup2, don’t check every call whether thedup3syscall exists or not.

bpo-21060: Rewrite confusing message from setup.py upload from “No distfile created in earlier command” to the more helpful “Must create andupload files in one command”.

bpo-32857: Intkinter,after_cancel(None) now raises aValueError instead of canceling the first scheduled function.Patch by Cheryl Sabella.

bpo-32852: Make sure sys.argv remains as a list when running trace.

bpo-32841: Fixedasyncio.Condition issue which silently ignoredcancellation after notifying and cancelling a conditional lock. Patch byBar Harel.

bpo-31787: Fixed refleaks of__init__() methods in various modules.(Contributed by Oren Milman)

bpo-30157: Fixed guessing quote and delimiter in csv.Sniffer.sniff() whenonly the last field is quoted. Patch by Jake Davis.

bpo-32394: socket: Remove TCP_FASTOPEN, TCP_KEEPCNT flags on older versionWindows during run-time.

bpo-32777: Fix a rare but potential pre-exec child process deadlock insubprocess on POSIX systems when marking file descriptors inheritable onexec in the child process. This bug appears to have been introduced in3.4.

bpo-32647: The ctypes module used to depend on indirect linking fordlopen. The shared extension is now explicitly linked against libdl onplatforms with dl.

bpo-32734: Fixedasyncio.Lock() safety issue which allowed acquiringand locking the same lock multiple times, without it being free. Patch byBar Harel.

bpo-32727: Do not include name field in SMTP envelope from address. Patchby Stéphane Wirtel

bpo-27931: Fix email address header parsing error when the username is anempty quoted string. Patch by Xiang Zhang.

bpo-32304: distutils’ upload command no longer corrupts tar files endingwith a CR byte, and no longer tries to convert CR to CRLF in any of theupload text fields.

bpo-32502: uuid.uuid1 no longer raises an exception if a 64-bit hardwareaddress is encountered.

bpo-31848: Fix the error handling in Aifc_read.initfp() when the SSNDchunk is not found. Patch by Zackery Spytz.

bpo-32555: On FreeBSD and Solaris, os.strerror() now always decode thebyte string from the current locale encoding, rather than usingASCII/surrogateescape in some cases.

bpo-32521: The nis module is now compatible with new libnsl and headerslocation.

bpo-32473: Improve ABCMeta._dump_registry() output readability

bpo-32521: glibc has removed Sun RPC. Use replacement libtirpc headers andlibrary in nis module.

bpo-32228: Ensure thattruncate() preserves the file position (asreported bytell()) after writes longer than the buffer size.

bpo-26133: Don’t unsubscribe signals in asyncio UNIX event loop oninterpreter shutdown.

bpo-32185: The SSL module no longer sends IP addresses in SNI TLSextension on platforms with OpenSSL 1.0.2+ or inet_pton.

bpo-32323:urllib.parse.urlsplit() does not convert zone-id(scope) to lower case for scoped IPv6 addresses in hostnames now.

bpo-32302: Fix bdist_wininst of distutils for CRT v142: it binarycompatible with CRT v140.

bpo-32255: A single empty field is now always quoted when written into aCSV file. This allows to distinguish an empty row from a row consisting ofa single empty field. Patch by Licht Takeuchi.

bpo-32277: RaiseNotImplementedError instead ofSystemError onplatforms wherechmod(...,follow_symlinks=False) is not supported.Patch by Anthony Sottile.

bpo-32199: The getnode() ip getter now uses ‘ip link’ instead of ‘ip linklist’.

bpo-27456: Ensure TCP_NODELAY is set on Linux. Tests by Victor Stinner.

bpo-31900: Thelocale.localeconv() function now sets temporarily theLC_CTYPE locale to theLC_NUMERIC locale to decodedecimal_point andthousands_sep byte strings if they are non-ASCIIor longer than 1 byte, and theLC_NUMERIC locale is different than theLC_CTYPE locale. This temporary change affects other threads.

Same change for thestr.format() method when formatting a number(int,float,float and subclasses) with then type (ex:'{:n}'.format(1234)).

bpo-31802: Importing native path module (posixpath,ntpath) nowworks even if theos module still is not imported.

bpo-17232: Clarify docs for -O and -OO. Patch by Terry Reedy.

bpo-32800: Update link to w3c doc for xml default namespaces.

bpo-8722: Document__getattr__() behavior when propertyget()method raisesAttributeError.

bpo-32614: Modify RE examples in documentation to use raw strings topreventDeprecationWarning and add text to REGEX HOWTO to highlightthe deprecation.

bpo-31972: Improve docstrings forpathlib.PurePath subclasses.

bpo-17799: Explain real behaviour of sys.settrace and sys.setprofile andtheir C-API counterparts regarding which type of events are received ineach function. Patch by Pablo Galindo Salgado.

bpo-32517: Fix failingtest_asyncio on macOS 10.12.2+ due to transportofKqueueSelector loop was not being closed.

bpo-32721: Fix test_hashlib to not fail if the _md5 module is not built.

bpo-32252: Fix faulthandler_suppress_crash_report() used to prevent coredump files when testing crashes. getrlimit() returns zero on success.

bpo-31518: Debian Unstable has disabled TLS 1.0 and 1.1 forSSLv23_METHOD(). Change TLS/SSL protocol of some tests to PROTOCOL_TLS orPROTOCOL_TLSv1_2 to make them pass on Debian.

bpo-32635: Fix segfault of the crypt module when libxcrypt is providedinstead of libcrypt at the system.

bpo-33016: Fix potential use of uninitialized memory innt._getfinalpathname

bpo-32903: Fix a memory leak in os.chdir() on Windows if the currentdirectory is set to a UNC path.

bpo-31966: Fixed WindowsConsoleIO.write() for writing empty data.

bpo-32409: Ensures activate.bat can handle Unicode contents.

bpo-32457: Improves handling of denormalized executable path whenlaunching Python.

bpo-32370: Use the correct encoding for ipconfig output in the uuidmodule. Patch by Segev Finer.

bpo-29248: Fixos.readlink() on Windows, which was mistakenlytreating thePrintNameOffset field of the reparse data buffer as anumber of characters instead of bytes. Patch by Craig Holmquist and SSE4.

bpo-32588: Create standalone _distutils_findvs module.

bpo-32726: Provide an additional, more modern macOS installer variant thatsupports macOS 10.9+ systems in 64-bit mode only. Upgrade the suppliedthird-party libraries to OpenSSL 1.0.2n, XZ 5.2.3, and SQLite 3.22.0. The10.9+ installer now links with and supplies its own copy of Tcl/Tk 8.6.8.

bpo-32984: Set__file__ while running a startup file. Like Python,IDLE optionally runs one startup file in the Shell window beforepresenting the first interactive input prompt. For IDLE,-s runs afile named in environmental variableIDLESTARTUP orPYTHONSTARTUP;-rfile runsfile. Python sets__file__ to the startup file name before running the file and unsetsit before the first prompt. IDLE now does the same when run normally,without the-n option.

bpo-32940: Simplify and rename StringTranslatePseudoMapping in pyparse.

bpo-32916: Changestr tocode in pyparse.

bpo-32905: Remove unused code in pyparse module.

bpo-32874: Add tests for pyparse.

bpo-32837: Using the system and place-dependent default encoding foropen() is a bad idea for IDLE’s system and location-independent files.

bpo-32826: Add “encoding=utf-8” to open() in IDLE’s test_help_about. GUItest test_file_buttons() only looks at initial ascii-only lines, butfailed on systems where open() defaults to ‘ascii’ because readline()internally reads and decodes far enough ahead to encounter a non-asciicharacter in CREDITS.txt.

bpo-32765: Update configdialog General tab docstring to add new widgets tothe widget list.

bpo-24960: 2to3 and lib2to3 can now read pickled grammar files usingpkgutil.get_data() rather than probing the filesystem. This lets 2to3 andlib2to3 work when run from a zipfile.

bpo-32222: Fix pygettext not extracting docstrings for functions with typeannotated arguments. Patch by Toby Harradine.

bpo-29084: Undocumented C API for OrderedDict has been excluded from thelimited C API. It was added by mistake and actually never worked in thelimited C API.

bpo-32176: co_flags.CO_NOFREE is now always set correctly by the codeobject constructor based on freevars and cellvars, rather than needing tobe set correctly by the caller. This ensures it will be clearedautomatically when additional cell references are injected into a modifiedcode object and function.

bpo-31949: Fixed several issues in printing tracebacks(PyTraceBack_Print()).

• Setting sys.tracebacklimit to 0 or less now suppresses printing tracebacks.

• Setting sys.tracebacklimit to None now causes using the default limit.

• Setting sys.tracebacklimit to an integer larger than LONG_MAX now means usingthe limit LONG_MAX rather than the default limit.

• Fixed integer overflows in the case of more than 2**31 traceback items onWindows.

• Fixed output errors handling.

bpo-30696: Fix the interactive interpreter looping endlessly when nomemory.

bpo-20047: Bytearray methods partition() and rpartition() now accept onlybytes-like objects as separator, as documented. In particular they nowraise TypeError rather of returning a bogus result when an integer ispassed as a separator.

bpo-31852: Fix a segmentation fault caused by a combination of the asyncsoft keyword and continuation lines.

bpo-21720: BytesWarning no longer emitted when thefromlist argument of__import__() or the__all__ attribute of the module contain bytesinstances.

bpo-31825: Fixed OverflowError in the ‘unicode-escape’ codec and incodecs.escape_decode() when decode an escaped non-ascii byte.

bpo-28603: Print the full context/cause chain of exceptions on interpreterexit, even if an exception in the chain is unhashable or compares equal tolater ones. Patch by Zane Bitter.

bpo-31786: Fix timeout rounding in the select module to round correctlynegative timeouts between -1.0 and 0.0. The functions now block waitingfor events as expected. Previously, the call was incorrectly non-blocking.Patch by Pablo Galindo.

bpo-31642: Restored blocking “from package import module” by settingsys.modules[“package.module”] to None.

bpo-31626: Fixed a bug in debug memory allocator. There was a write tofreed memory after shrinking a memory block.

bpo-31619: Fixed a ValueError when convert a string with large number ofunderscores to integer with binary base.

bpo-31592: Fixed an assertion failure in Python parser in case of a badunicodedata.normalize(). Patch by Oren Milman.

bpo-31588: Raise aTypeError with a helpful error message when classcreation fails due to a metaclass with a bad__prepare__() method.Patch by Oren Milman.

bpo-31566: Fix an assertion failure in_warnings.warn() in case of a bad__name__ global. Patch by Oren Milman.

bpo-31505: Fix an assertion failure injson, in case_json.make_encoder() received a badencoder() argument. Patch by OrenMilman.

bpo-31492: Fix assertion failures in case of failing to import from amodule with a bad__name__ attribute, and in case of failing to accessan attribute of such a module. Patch by Oren Milman.

bpo-31490: Fix an assertion failure inctypes class definition, in casethe class has an attribute whose name is specified in_anonymous_ butnot in_fields_. Patch by Oren Milman.

bpo-31478: Fix an assertion failure in_random.Random.seed() in case theargument has a bad__abs__() method. Patch by Oren Milman.

bpo-31315: Fix an assertion failure in imp.create_dynamic(), whenspec.name is not a string. Patch by Oren Milman.

bpo-31311: Fix a crash in the__setstate__() method ofctypes._CData, in case of a bad__dict__. Patch by Oren Milman.

bpo-31293: Fix crashes in true division and multiplication of a timedeltaobject by a float with a bad as_integer_ratio() method. Patch by OrenMilman.

bpo-31285: Fix an assertion failure inwarnings.warn_explicit, when thereturn value of the received loader’s get_source() has a bad splitlines()method. Patch by Oren Milman.

bpo-30817:PyErr_PrintEx() clears now the ignored exception that may beraised by_PySys_SetObjectId(), for example when no memory.

bpo-28556: Two minor fixes fortyping module: allow shallow copyinginstances of generic classes, improve interaction of__init_subclass__with generics. Original PRs by Ivan Levkivskyi.

bpo-27240: The header folding algorithm for the new email policies hasbeen rewritten, which also fixesbpo-30788,bpo-31831, andbpo-32182. Inparticular, RFC2231 folding is now done correctly.

bpo-32186: io.FileIO.readall() and io.FileIO.read() now release the GILwhen getting the file size. Fixed hang of all threads with inaccessibleNFS server. Patch by Nir Soffer.

bpo-12239: Makemsilib.SummaryInformation.GetProperty() returnNone when the value of property isVT_EMPTY. Initial patch byMark Mc Mahon.

bpo-31325: Fix wrong usage ofcollections.namedtuple() in theRobotFileParser.parse()method.

Initial patch by Robin Wellner.

bpo-12382:msilib.OpenDatabase() now raises a better exceptionmessage when it couldn’t open or create an MSI file. Initial patch byWilliam Tisäter.

bpo-32110:codecs.StreamReader.read(n) now returns not more thanncharacters/bytes for non-negativen. This makes it compatible withread() methods of other file-like objects.

bpo-32072: Fixed issues with binary plists:

• Fixed saving bytearrays.

• Identical objects will be saved only once.

• Equal references will be load as identical objects.

• Added support for saving and loading recursive data structures.

bpo-32034: Make asyncio.IncompleteReadError and LimitOverrunErrorpickleable.

bpo-32015: Fixed the looping of asyncio in the case of reconnection thesocket during waiting async read/write from/to the socket.

bpo-32011: Restored support of loading marshal files with the TYPE_INT64code. These files can be produced in Python 2.7.

bpo-31970: Reduce performance overhead of asyncio debug mode.

bpo-9678: Fixed determining the MAC address in the uuid module:

• Using ifconfig on NetBSD and OpenBSD.

• Using arp on Linux, FreeBSD, NetBSD and OpenBSD.

Based on patch by Takayuki Shimizukawa.

bpo-30057: Fix potential missed signal in signal.signal().

bpo-31933: Fix Blake2 params leaf_size and node_offset on big endianplatforms. Patch by Jack O’Connor.

bpo-31927: Fixed compilation of the socket module on NetBSD 8. Fixedassertion failure or reading arbitrary data when parse a AF_BLUETOOTHaddress on NetBSD and DragonFly BSD.

bpo-27666: Fixed stack corruption in curses.box() and curses.ungetmouse()when the size of types chtype or mmask_t is less than the size of C long.curses.box() now accepts characters as arguments. Based on patch by SteveFink.

bpo-31897: plistlib now catches more errors when read binary plists andraises InvalidFileException instead of unexpected exceptions.

bpo-25720: Fix the method for checking pad state of curses WINDOW. Patchby Masayuki Yamamoto.

bpo-31893: Fixed the layout of the kqueue_event structure on OpenBSD andNetBSD. Fixed the comparison of the kqueue_event objects.

bpo-31891: Fixed building the curses module on NetBSD.

bpo-28416: Instances of pickle.Pickler subclass with the persistent_id()method and pickle.Unpickler subclass with the persistent_load() method nolonger create reference cycles.

bpo-28326: Fix multiprocessing.Process when stdout and/or stderr is closedor None.

bpo-31457: If nested log adapters are used, the innerprocess()methods are no longer omitted.

bpo-31457: Themanager property on LoggerAdapter objects is nowproperly settable.

bpo-31806: Fix timeout rounding in time.sleep(), threading.Lock.acquire()and socket.socket.settimeout() to round correctly negative timeoutsbetween -1.0 and 0.0. The functions now block waiting for events asexpected. Previously, the call was incorrectly non-blocking. Patch byPablo Galindo.

bpo-28603: traceback: Fix a TypeError that occurred during printing ofexception tracebacks when either the current exception or an exception inits context/cause chain is unhashable. Patch by Zane Bitter.

bpo-30058: Fixed buffer overflow in select.kqueue.control().

bpo-31770: Prevent a crash when calling the__init__() method of asqlite3.Cursor object more than once. Patch by Oren Milman.

bpo-31672:idpattern instring.Template matched some non-ASCIIcharacters. Now it uses-i regular expression local flag to avoidnon-ASCII characters.

bpo-31764: Prevent a crash insqlite3.Cursor.close() in case theCursor object is uninitialized. Patch by Oren Milman.

bpo-31752: Fix possible crash in timedelta constructor called with customintegers.

bpo-31701: On Windows, faulthandler.enable() now ignores MSC and COMexceptions.

bpo-31728: Prevent crashes in_elementtree due to unsafe cleanup ofElement.text andElement.tail. Patch by Oren Milman.

bpo-31620: an empty asyncio.Queue now doesn’t leak memory when queue.getpollers timeout

bpo-31632: Fix method set_protocol() of class _SSLProtocolTransport inasyncio module. This method was previously modifying a wrong reference tothe protocol.

bpo-31675: Fixed memory leaks in Tkinter’s methods splitlist() and split()when pass a string larger than 2 GiB.

bpo-31673: Fixed typo in the name of Tkinter’s method adderrorinfo().

bpo-30806: Fix the string representation of a netrc object.

bpo-15037: Added a workaround for getkey() in curses for ncurses 5.7 andearlier.

bpo-25351: Avoid venv activate failures with undefined variables

bpo-25532: inspect.unwrap() will now only try to unwrap an objectsys.getrecursionlimit() times, to protect against objects which create anew object on every attribute access.

bpo-30347: Stop crashes when concurrently iterate over itertools.groupby()iterators.

bpo-31516:threading.current_thread() should not return a dummy threadat shutdown.

bpo-31351: python -m ensurepip now exits with non-zero exit code if pipbootstrapping has failed.

bpo-31482:random.seed() now works with bytes in version=1

bpo-31334: Fixpoll.poll([timeout]) in theselect module forarbitrary negative timeouts on all OSes where it can only be anon-negative integer or -1. Patch by Riccardo Coccioli.

bpo-31310: multiprocessing’s semaphore tracker should be launched again ifcrashed.

bpo-31308: Make multiprocessing’s forkserver process immune to Ctrl-C andother user interruptions. If it crashes, restart it when necessary.

bpo-32105: Added asyncio.BaseEventLoop.connect_accepted_socketversionadded marker.

bpo-31537: Fix incorrect usage ofget_history_length in readlinedocumentation example code. Patch by Brad Smith.

bpo-30085: The operator functions without double underscores are preferredfor clarity. The one with underscores are only kept forback-compatibility.

bpo-31380: Skip test_httpservers test_undecodable_file on macOS: fails onAPFS.

bpo-31705: Skip test_socket.test_sha256() on Linux kernel older than 4.5.The test fails with ENOKEY on kernel 3.10 (on ppc64le). A fix was mergedinto the kernel 4.5.

bpo-31174: Fix test_tools.test_unparse: DirectoryTestCase now stores thenames sample to always test the same files. It prevents false alarms whenhunting reference leaks.

bpo-30695: Add theset_nomemory(start,stop) andremove_mem_hooks()functions to the _testcapi module.

bpo-32059:detect_modules() insetup.py now also searches thesysroot paths when cross-compiling.

bpo-31957: Fixes Windows SDK version detection when building for Windows.

bpo-31609: Fixes quotes in PCbuild/clean.bat

bpo-31934: Abort the build when building out of a not clean source tree.

bpo-31926: Fixed Argument Clinic sometimes causing compilation errors whenthere was more than one function and/or method in a .c file with the samename.

bpo-28791: Update Windows builds to use SQLite 3.21.0.

bpo-28791: Update OS X installer to use SQLite 3.21.0.

bpo-22140: Prevent double substitution of prefix in python-config.sh.

bpo-31536: Avoid wholesale rebuild aftermakeregen-all if nothingchanged.

bpo-1102: ReturnNone whenView.Fetch() returnsERROR_NO_MORE_ITEMS instead of raisingMSIError.

Initial patch by Anthony Tuininga.

bpo-31944: Fixes Modify button in Apps and Features dialog.

bpo-31392: Update macOS installer to use OpenSSL 1.0.2m

bpo-32207: Improve tk event exception tracebacks in IDLE. When tk eventhandling is driven by IDLE’s run loop, a confusing and distractingqueue.EMPTY traceback context is no longer added to tk event exceptiontracebacks. The traceback is now the same as when event handling isdriven by user code. Patch based on a suggestion by Serhiy Storchaka.

bpo-32164: Delete unused file idlelib/tabbedpages.py. Use of TabbedPageSetin configdialog was replaced by ttk.Notebook.

bpo-32100: IDLE: Fix old and new bugs in pathbrowser; improve tests. Patchmostly by Cheryl Sabella.

bpo-31858: IDLE – Restrict shell prompt manipulation to the shell. Editorand output windows only see an empty last prompt line. This simplifiesthe code and fixes a minor bug when newline is inserted. Sys.ps1, ifpresent, is read on Shell start-up, but is not set or changed.

bpo-31860: The font sample in the IDLE configuration dialog is noweditable. Changes persist while IDLE remains open

bpo-31836: Test_code_module now passes if run after test_idle, which setsps1.

The code module uses sys.ps1 if present or sets it to ‘>>> ‘ if not.Test_code_module now properly tests both behaviors. Ditto for ps2.

bpo-28603: Fix a TypeError that caused a shell restart when printing atraceback that includes an exception that is unhashable. Patch by ZaneBitter.

bpo-13802: Use non-Latin characters in the IDLE’s Font settings sample.Even if one selects a font that defines a limited subset of the unicodeBasic Multilingual Plane, tcl/tk will use other fonts that define acharacter. The expanded example give users of non-Latin characters abetter idea of what they might see in IDLE’s shell and editors. To makeroom for the expanded sample, frames on the Font tab are re-arranged. TheFont/Tabs help explains a bit about the additions.

bpo-31460: Simplify the API of IDLE’s Module Browser.

Passing a widget instead of an flist with a root widget opens the optionof creating a browser frame that is only part of a window. Passing a fullfile name instead of pieces assumed to come from a .py file opens thepossibility of browsing python files that do not end in .py.

bpo-31649: IDLE - Make _htest, _utest parameters keyword only.

bpo-31559: Remove test order dependence in idle_test.test_browser.

bpo-31459: Rename IDLE’s module browser from Class Browser to ModuleBrowser. The original module-level class and method browser became amodule browser, with the addition of module-level functions, years ago.Nested classes and functions were added yesterday. Forback-compatibility, the virtual event <<open-class-browser>>, whichappears on the Keys tab of the Settings dialog, is not changed. Patch byCheryl Sabella.

bpo-31500: Default fonts now are scaled on HiDPI displays.

bpo-1612262: IDLE module browser now shows nested classes and functions.Original patches for code and tests by Guilherme Polo and Cheryl Sabella,respectively.

bpo-30722: Make redemo work with Python 3.6 and newer versions.

Also, remove theLOCALE option since it doesn’t work with stringpatterns in Python 3.

Patch by Christoph Sarnowski.

bpo-20891: Fix PyGILState_Ensure(). When PyGILState_Ensure() is called ina non-Python thread before PyEval_InitThreads(), only callPyEval_InitThreads() after calling PyThreadState_New() to fix a crash.

bpo-31532: Fix memory corruption due to allocator mix in getpath.c betweenPy_GetPath() and Py_SetPath()

bpo-30697: ThePyExc_RecursionErrorInst singleton is removed andPyErr_NormalizeException() does not use it anymore. This singleton ispersistent and its members being never cleared may cause a segfault duringfinalization of the interpreter. See alsobpo-22898.

bpo-31641: Re-allow arbitrary iterables inconcurrent.futures.as_completed(). Fixes regression in 3.6.3rc1.

bpo-31662: Fix typos in Windowsuploadrelease.bat script. Fix WindowsDoc build issues inDoc/make.bat.

bpo-31423: Fix building the PDF documentation with newer versions ofSphinx.

bpo-29781: SSLObject.version() now correctly returns None when handshakeover BIO has not been performed yet.

bpo-30947: Upgrade libexpat embedded copy from version 2.2.1 to 2.2.3 toget security fixes.

bpo-31471: Fix an assertion failure insubprocess.Popen() on Windows, incase the env argument has a bad keys() method. Patch by Oren Milman.

bpo-31418: Fix an assertion failure inPyErr_WriteUnraisable() in caseof an exception with a bad__module__ attribute. Patch by Oren Milman.

bpo-31416: Fix assertion failures in case of a bad warnings.filters orwarnings.defaultaction. Patch by Oren Milman.

bpo-31411: Raise a TypeError instead of SystemError in casewarnings.onceregistry is not a dictionary. Patch by Oren Milman.

bpo-31373: Fix several possible instances of undefined behavior due tofloating-point demotions.

bpo-30465: Location information (lineno andcol_offset) inf-strings is now (mostly) correct. This fixes tools like flake8 fromshowing warnings on the wrong line (typically the first line of the file).

bpo-31343: Include sys/sysmacros.h for major(), minor(), and makedev().GNU C libray plans to remove the functions from sys/types.h.

bpo-31291: Fix an assertion failure inzipimport.zipimporter.get_data onWindows, when the return value ofpathname.replace('/','\\') isn’t astring. Patch by Oren Milman.

bpo-31271: Fix an assertion failure in the write() method ofio.TextIOWrapper, when the encoder doesn’t return a bytes object. Patchby Oren Milman.

bpo-31243: Fix a crash in some methods ofio.TextIOWrapper, when thedecoder’s state is invalid. Patch by Oren Milman.

bpo-30721:print now shows correct usage hint for using Python 2redirection syntax. Patch by Sanyam Khurana.

bpo-31070: Fix a race condition in importlib _get_module_lock().

bpo-31095: Fix potential crash during GC caused bytp_dealloc whichdoesn’t callPyObject_GC_UnTrack().

bpo-31071: Avoid masking original TypeError in call with * unpacking whenother arguments are passed.

bpo-30978: str.format_map() now passes key lookup exceptions through.Previously any exception was replaced with a KeyError exception.

bpo-30808: Use _Py_atomic API for concurrency-sensitive signal state.

bpo-30876: Relative import from unloaded package now reimports the packageinstead of failing with SystemError. Relative import from non-package nowfails with ImportError rather than SystemError.

bpo-30703: Improve signal delivery.

Avoid using Py_AddPendingCall from signal handler, to avoid callingsignal-unsafe functions. The tests I’m adding here fail without the restof the patch, on Linux and OS X. This means our signal delivery logic haddefects (some signals could be lost).

bpo-30765: Avoid blocking in pthread_mutex_lock() whenPyThread_acquire_lock() is asked not to block.

bpo-31161: Make sure the ‘Missing parentheses’ syntax error message isonly applied to SyntaxError, not to subclasses. Patch by Martijn Pieters.

bpo-30814: Fixed a race condition when import a submodule from a package.

bpo-30597:print now shows expected input in custom error message whenused as a Python 2 statement. Patch by Sanyam Khurana.

bpo-31499: xml.etree: Fix a crash when a parser is part of a referencecycle.

bpo-28556: typing.get_type_hints now finds the right globalns for classesand modules by default (when noglobalns was specified by the caller).

bpo-28556: Speed improvements to thetyping module. Original PRs byIvan Levkivskyi and Mitar.

bpo-31544: The C accelerator module of ElementTree ignored exceptionsraised when looking up TreeBuilder target methods in XMLParser().

bpo-31234: socket.create_connection() now fixes manually a referencecycle: clear the variable storing the last exception on success.

bpo-31457: LoggerAdapter objects can now be nested.

bpo-31400: Improves SSL error handling to avoid losing error numbers.

bpo-28958: ssl.SSLContext() now uses OpenSSL error information when acontext cannot be instantiated.

bpo-27340: SSLSocket.sendall() now uses memoryview to create slices ofdata. This fixes support for all bytes-like object. It is also moreefficient and avoids costly copies.

bpo-31178: Fix string concatenation bug in rare error path in thesubprocess module

bpo-31350: Micro-optimizeasyncio._get_running_loop() to become upto 10% faster.

bpo-31170: expat: Update libexpat from 2.2.3 to 2.2.4. Fix copying ofpartial characters for UTF-8 input (libexpat bug 115):https://github.com/libexpat/libexpat/issues/115

bpo-29136: Add TLS 1.3 cipher suites and OP_NO_TLSv1_3.

bpo-29212: Fix concurrent.futures.thread.ThreadPoolExecutor threads tohave a non repr() based thread name by default when no thread_name_prefixis supplied. They will now identify themselves as“ThreadPoolExecutor-y_n”.

bpo-9146: Fix a segmentation fault in _hashopenssl when standard hashfunctions such as md5 are not available in the linked OpenSSL library. Asin some special FIPS-140 build environments.

bpo-27144: Themap() andas_completed() iterators inconcurrent.futures now avoid keeping a reference to yielded objects.

bpo-10746: Fix ctypes producing wrong PEP 3118 type codes for integertypes.

bpo-22536: The subprocess module now sets the filename whenFileNotFoundError is raised on POSIX systems due to the executable or cwdnot being found.

bpo-31249: concurrent.futures: WorkItem.run() used by ThreadPoolExecutornow breaks a reference cycle between an exception object and the WorkItemobject.

bpo-31247: xmlrpc.server now explicitly breaks reference cycles when usingsys.exc_info() in code handling exceptions.

bpo-30102: The ssl and hashlib modules now callOPENSSL_add_all_algorithms_noconf() on OpenSSL < 1.1.0. The functiondetects CPU features and enables optimizations on some CPU architecturessuch as POWER8. Patch is based on research from Gustavo Serra Scalet.

bpo-31185: Fixed miscellaneous errors in asyncio speedup module.

bpo-31135: ttk: fix the destroy() method of LabeledScale and OptionMenuclasses. Call the parent destroy() method even if the used attributedoesn’t exist. The LabeledScale.destroy() method now also explicitlyclears label and scale attributes to help the garbage collector to destroyall widgets.

bpo-31107: Fixcopyreg._slotnames() mangled attribute calculation forclasses whose name begins with an underscore. Patch by Shane Harvey.

bpo-31061: Fixed a crash when using asyncio and threads.

bpo-30502: Fix handling of long oids in ssl. Based on patch by ChristianHeimes.

bpo-30119: ftplib.FTP.putline() now throws ValueError on commands thatcontains CR or LF. Patch by Dong-hee Na.

bpo-30595: multiprocessing.Queue.get() with a timeout now polls its readerin non-blocking mode if it succeeded to acquire the lock but the acquiretook longer than the timeout.

bpo-29403: Fixunittest.mock’s autospec to not fail on method-boundbuiltin functions. Patch by Aaron Gallagher.

bpo-30961: Fix decrementing a borrowed reference in tracemalloc.

bpo-25684: Changettk.OptionMenu radiobuttons to be unique acrossinstances ofOptionMenu.

bpo-30886: Fix multiprocessing.Queue.join_thread(): it now waits until thethread completes, even if the thread was started by the same process whichcreated the queue.

bpo-29854: Fix segfault in readline when using readline’s history-sizeoption. Patch by Nir Soffer.

bpo-30319: socket.close() now ignores ECONNRESET error.

bpo-30828: Fix out of bounds write inasyncio.CFuture.remove_done_callback().

bpo-30807: signal.setitimer() may disable the timer when passed a tinyvalue.

Tiny values (such as 1e-6) are valid non-zero values for setitimer(),which is specified as taking microsecond-resolution intervals. However, onsome platform, our conversion routine could convert 1e-6 into a zerointerval, therefore disabling the timer instead of (re-)scheduling it.

bpo-30441: Fix bug when modifying os.environ while iterating over it

bpo-30532: Fix email header value parser dropping folding white space incertain cases.

bpo-30879: os.listdir() and os.scandir() now emit bytes names when calledwith bytes-like argument.

bpo-30746: Prohibited the ‘=’ character in environment variable names inos.putenv() andos.spawn*().

bpo-29755: Fixed the lgettext() family of functions in the gettext module.They now always return bytes.

bpo-31294: Fix incomplete code snippet in the ZeroMQSocketListener andZeroMQSocketHandler examples and adapt them to Python 3.

bpo-21649: Add RFC 7525 and Mozilla server side TLS links to SSLdocumentation.

bpo-30803: Clarify doc on truth value testing. Original patch by PeterThomassen.

bpo-31320: Silence traceback in test_ssl

bpo-25674: Remove sha256.tbs-internet.com ssl test

bpo-30715: Address ALPN callback changes for OpenSSL 1.1.0f. The latestversion behaves like OpenSSL 1.0.2 and no longer aborts handshake.

bpo-30822: regrtest: Exclude tzdata from regrtest –all. When running thetest suite using –use=all / -u all, exclude tzdata since it makestest_datetime too slow (15-20 min on some buildbots) which then times outon some buildbots. Fix also regrtest command line parser to allow passing-u extralargefile to run test_zipfile64.

bpo-30854: Fix compile error when compiling –without-threads. Patch byMasayuki Yamamoto.

bpo-30389: Adds detection of Visual Studio 2017 to distutils on Windows.

bpo-31340: Change to building with MSVC v141 (included with Visual Studio2017)

bpo-30581: os.cpu_count() now returns the correct number of processors onWindows when the number of logical processors is greater than 64.

bpo-30731: Add a missing xmlns to python.manifest so that it matches theschema.

bpo-31493: IDLE code context – fix code update and font update timers.

Canceling timers prevents a warning message when test_idle completes.

bpo-31488: IDLE - Update non-key options in former extension classes. Whenapplying configdialog changes, call .reload for each feature class. ChangeParenMatch so updated options affect existing instances attached toexisting editor windows.

bpo-31477: IDLE - Improve rstrip entry in doc. Strip trailing whitespacestrips more than blank spaces. Multiline string literals are not skipped.

bpo-31480: IDLE - make tests pass with zzdummy extension disabled bydefault.

bpo-31421: Document how IDLE runs tkinter programs. IDLE calls tcl/tkupdate in the background in order to make live

interaction and experimentation with tkinter applications much easier.

bpo-31414: IDLE – fix tk entry box tests by deleting first. Adding to anint entry is not the same as deleting and inserting because int(‘’) willfail.

bpo-31051: Rearrange IDLE configdialog GenPage into Window, Editor, andHelp sections.

bpo-30617: IDLE - Add docstrings and tests for outwin subclass of editor.

Move some data and functions from the class to module level. Patch byCheryl Sabella.

bpo-31287: IDLE - Do not modify tkinter.message in test_configdialog.

bpo-27099: Convert IDLE’s built-in ‘extensions’ to regular features.

About 10 IDLE features were implemented as supposedly optional extensions.Their different behavior could be confusing or worse for users and notgood for maintenance. Hence the conversion.

The main difference for users is that user configurable key bindings forbuiltin features are now handled uniformly. Now, editing a binding in akeyset only affects its value in the keyset. All bindings are definedtogether in the system-specific default keysets in config-extensions.def.All custom keysets are saved as a whole in config-extension.cfg. All takeeffect as soon as one clicks Apply or Ok.

The affected events are ‘<<force-open-completions>>’, ‘<<expand-word>>’,‘<<force-open-calltip>>’, ‘<<flash-paren>>’, ‘<<format-paragraph>>’,‘<<run-module>>’, ‘<<check-module>>’, and ‘<<zoom-height>>’. Any (global)customizations made before 3.6.3 will not affect their keyset-specificcustomization after 3.6.3. and vice versa.

Inital patch by Charles Wohlganger.

bpo-31206: IDLE: Factor HighPage(Frame) class from ConfigDialog. Patch byCheryl Sabella.

bpo-31001: Add tests for configdialog highlight tab. Patch by CherylSabella.

bpo-31205: IDLE: Factor KeysPage(Frame) class from ConfigDialog. Theslightly modified tests continue to pass. Patch by Cheryl Sabella.

bpo-31130: IDLE – stop leaks in test_configdialog. Initial patch byVictor Stinner.

bpo-31002: Add tests for configdialog keys tab. Patch by Cheryl Sabella.

bpo-19903: IDLE: Calltips useinspect.signature instead ofinspect.getfullargspec. This improves calltips for builtins converted touse Argument Clinic. Patch by Louie Lu.

bpo-31083: IDLE - Add an outline of a TabPage class in configdialog.Update existing classes to match outline. Initial patch by Cheryl Sabella.

bpo-31050: Factor GenPage(Frame) class from ConfigDialog. The slightlymodified tests continue to pass. Patch by Cheryl Sabella.

bpo-31004: IDLE - Factor FontPage(Frame) class from ConfigDialog.

Slightly modified tests continue to pass. Fix General tests. Patch mostlyby Cheryl Sabella.

bpo-30781: IDLE - Use ttk widgets in ConfigDialog. Patches by Terry JanReedy and Cheryl Sabella.

bpo-31060: IDLE - Finish rearranging methods of ConfigDialog Groupingmethods pertaining to each tab and the buttons will aid writing tests andimproving the tabs and will enable splitting the groups into classes.

bpo-30853: IDLE – Factor a VarTrace class out of ConfigDialog.

Instance tracers manages pairs consisting of a tk variable and a callbackfunction. When tracing is turned on, setting the variable calls thefunction. Test coverage for the new class is 100%.

bpo-31003: IDLE: Add more tests for General tab.

bpo-30993: IDLE - Improve configdialog font page and tests.

In configdialog: Document causal pathways in create_font_tab docstring.Simplify some attribute names. Move set_samples calls to var_changed_font(idea from Cheryl Sabella). Move related functions to positions after thecreate widgets function.

In test_configdialog: Fix test_font_set so not order dependent. Fixrenamed test_indent_scale so it tests the widget. Adjust tests formovement of set_samples call. Add tests for load functions. Put all fonttests in one class and tab indent tests in another. Except for two lines,these tests completely cover the related functions.

bpo-30981: IDLE – Add more configdialog font page tests.

bpo-28523: IDLE: replace ‘colour’ with ‘color’ in configdialog.

bpo-30917: Add tests for idlelib.config.IdleConf. Increase coverage from46% to 96%. Patch by Louie Lu.

bpo-30934: Document coverage details for idlelib tests.

• Add section to idlelib/idle-test/README.txt.

• Include check that branches are taken both ways.

• Exclude IDLE-specific code that does not run during unit tests.

bpo-30913: IDLE: Document ConfigDialog tk Vars, methods, and widgets indocstrings This will facilitate improving the dialog and splitting up theclass. Original patch by Cheryl Sabella.

bpo-30899: IDLE: Add tests for ConfigParser subclasses in config. Patch byLouie Lu.

bpo-30881: IDLE: Add docstrings to browser.py. Patch by Cheryl Sabella.

bpo-30851: IDLE: Remove unused variables in configdialog. One is aduplicate, one is set but cannot be altered by users. Patch by CherylSabella.

bpo-30870: IDLE: In Settings dialog, select font with Up, Down keys aswell as mouse. Initial patch by Louie Lu.

bpo-8231: IDLE: call config.IdleConf.GetUserCfgDir only once.

bpo-30779: IDLE: Factor ConfigChanges class from configdialog, put inconfig; test. * In config, put dump test code in a function; run it andunittest in ‘if __name__ == ‘__main__’. * Add class config.ConfigChangesbased on changes_class_v4.py on bpo issue. * Add classtest_config.ChangesTest, partly using configdialog_tests_v1.py. * Reviseconfigdialog to use ConfigChanges; see tracker msg297804. * Revisetest_configdialog to match configdialog changes. * Remove configdialogfunctions unused or moved to ConfigChanges. Cheryl Sabella contributedparts of the patch.

bpo-30777: IDLE: configdialog - Add docstrings and fix comments. Patch byCheryl Sabella.

bpo-30495: IDLE: Improve textview with docstrings, PEP8 names, and moretests. Patch by Cheryl Sabella.

bpo-30723: IDLE: Make several improvements to parenmatch. Add ‘parens’style to highlight both opener and closer. Make ‘default’ style, which isnot default, a synonym for ‘opener’. Make time-delay work the same withall styles. Add help for config dialog extensions tab, including help forparenmatch. Add new tests. Original patch by Charles Wohlganger.

bpo-30674: IDLE: add docstrings to grep module. Patch by Cheryl Sabella

bpo-21519: IDLE’s basic custom key entry dialog now detects duplicatesproperly. Original patch by Saimadhav Heblikar.

bpo-29910: IDLE no longer deletes a character after commenting out aregion by a key shortcut. Addreturn'break' for this and otherpotential conflicts between IDLE and default key bindings.

bpo-30728: Review and change idlelib.configdialog names. Lowercase methodand attribute names. Replace ‘colour’ with ‘color’, expand overly crypticnames, delete unneeded underscores. Replaceimport* with specificimports. Patches by Cheryl Sabella.

bpo-6739: IDLE: Verify user-entered key sequences by trying to bind themwith tk. Add tests for all 3 validation functions. Original patch by GPolo. Tests added by Cheryl Sabella.

bpo-30983: gdb integration commands (py-bt, etc.) work on optimized sharedbuilds now, too. PEP 523 introduced _PyEval_EvalFrameDefault whichinlines PyEval_EvalFrameEx on non-debug shared builds. This broke theability to use py-bt, py-up, and a few other Python-specific gdbintegrations. The problem is fixed by only looking for_PyEval_EvalFrameDefault frames in python-gdb.py. Original patch by Bruno“Polaco” Penteado.

bpo-30730: Prevent environment variables injection in subprocess onWindows. Prevent passing other environment variables and commandarguments.

bpo-30694: Upgrade expat copy from 2.2.0 to 2.2.1 to get fixes of multiplesecurity vulnerabilities including: CVE-2017-9233 (External entityinfinite loop DoS), CVE-2016-9063 (Integer overflow, re-fix),CVE-2016-0718 (Fix regression bugs from 2.2.0’s fix to CVE-2016-0718) andCVE-2012-0876 (Counter hash flooding with SipHash). Note: theCVE-2016-5300 (Use os-specific entropy sources like getrandom) doesn’timpact Python, since Python already gets entropy from the OS to set theexpat secret usingXML_SetHashSalt().

bpo-30500: Fix urllib.parse.splithost() to correctly parse fragments. Forexample,splithost('//127.0.0.1#@evil.com/') now correctly returns the127.0.0.1 host, instead of treating@evil.com as the host in anauthentication (login@host).

bpo-30682: Removed a too-strict assertion that failed for certainf-strings, such as eval(“f’\n’”) and eval(“f’\r’”).

bpo-30604: Move co_extra_freefuncs to not be per-thread to avoid crashes

bpo-29104: Fixed parsing backslashes in f-strings.

bpo-27945: Fixed various segfaults with dict when input collections aremutated during searching, inserting or comparing. Based on patches byDuane Griffin and Tim Mitchell.

bpo-25794: Fixed type.__setattr__() and type.__delattr__() fornon-interned attribute names. Based on patch by Eryk Sun.

bpo-30039: If a KeyboardInterrupt happens when the interpreter is in themiddle of resuming a chain of nested ‘yield from’ or ‘await’ calls, it’snow correctly delivered to the innermost frame.

bpo-12414: sys.getsizeof() on a code object now returns the sizes whichincludes the code struct and sizes of objects which it references. Patchby Dong-hee Na.

bpo-29949: Fix memory usage regression of set and frozenset object.

bpo-29935: Fixed error messages in the index() method of tuple, list anddeque when pass indices of wrong type.

bpo-29859: Show correct error messages when any of the pthread_* calls inthread_pthread.h fails.

bpo-28876:bool(range) works even iflen(range) raisesOverflowError.

bpo-29600: Fix wrapping coroutine return values in StopIteration.

bpo-28856: Fix an oversight that %b format for bytes should supportobjects follow the buffer protocol.

bpo-29714: Fix a regression that bytes format may fail when containingzero bytes inside.

bpo-29478: If max_line_length=None is specified while using the Compat32policy, it is no longer ignored. Patch by Mircea Cosbuc.

bpo-30616: Functional API of enum allows to create empty enums. Patched byDong-hee Na

bpo-30038: Fix race condition between signal delivery and wakeup filedescriptor. Patch by Nathaniel Smith.

bpo-23894: lib2to3 now recognizesrb'...' andf'...' strings.

bpo-23890: unittest.TestCase.assertRaises() now manually breaks areference cycle to not keep objects alive longer than expected.

bpo-30149: inspect.signature() now supports callables withvariable-argument parameters wrapped with partialmethod. Patch by Dong-heeNa.

bpo-30645: Fix path calculation in imp.load_package(), fixing it for caseswhen a package is only shipped with bytecodes. Patch by AlexandruArdelean.

bpo-29931: Fixed comparison check for ipaddress.ip_interface objects.Patch by Sanjay Sundaresan.

bpo-30605: re.compile() no longer raises a BytesWarning when compiling abytes instance with misplaced inline modifier. Patch by Roy Williams.

bpo-29591: Update expat copy from 2.1.1 to 2.2.0 to get fixes ofCVE-2016-0718 and CVE-2016-4472. Seehttps://sourceforge.net/p/expat/bugs/537/ for more information.

bpo-24484: Avoid race condition in multiprocessing cleanup (#2159)

bpo-28994: The traceback no longer displayed for SystemExit raised in acallback registered by atexit.

bpo-30508: Don’t log exceptions if Task/Future “cancel()” method wascalled.

bpo-28556: Updates to typing module: Add generic AsyncContextManager, addsupport for ContextManager on all versions. Original PRs by Jelle Zijlstraand Ivan Levkivskyi

bpo-29870: Fix ssl sockets leaks when connection is aborted in asyncio/sslimplementation. Patch by Michaël Sghaïer.

bpo-29743: Closing transport during handshake process leaks open socket.Patch by Nikolay Kim

bpo-27585: Fix waiter cancellation in asyncio.Lock. Patch by MathieuSornay.

bpo-30418: On Windows, subprocess.Popen.communicate() now also ignoreEINVAL on stdin.write() if the child process is still running but closedthe pipe.

bpo-29822: inspect.isabstract() now works during __init_subclass__. Patchby Nate Soares.

bpo-29581: ABCMeta.__new__ now accepts**kwargs, allowing abstractbase classes to use keyword parameters in __init_subclass__. Patch by NateSoares.

bpo-30557: faulthandler now correctly filters and displays exception codeson Windows

bpo-30378: Fix the problem that logging.handlers.SysLogHandler cannothandle IPv6 addresses.

bpo-29960: Preserve generator state when _random.Random.setstate() raisesan exception. Patch by Bryan Olson.

bpo-30414: multiprocessing.Queue._feed background running thread do notbreak from main loop on exception.

bpo-30003: Fix handling escape characters in HZ codec. Based on patch byMa Lin.

bpo-30301: Fix AttributeError when using SimpleQueue.empty() underspawnandforkserver start methods.

bpo-30329: imaplib and poplib now catch the Windows socket WSAEINVAL error(code 10022) on shutdown(SHUT_RDWR): An invalid operation was attempted.This error occurs sometimes on SSL connections.

bpo-30375: Warnings emitted when compile a regular expression now alwayspoint to the line in the user code. Previously they could point intoinners of the re module if emitted from inside of groups or conditionals.

bpo-30048: FixedTask.cancel() can be ignored when the task is runningcoroutine and the coroutine returned without any moreawait.

bpo-30266: contextlib.AbstractContextManager now supportsanti-registration by setting __enter__ = None or __exit__ = None,following the pattern introduced inbpo-25958. Patch by Jelle Zijlstra.

bpo-30298: Weaken the condition of deprecation warnings for inlinemodifiers. Now allowed several subsequential inline modifiers at the startof the pattern (e.g.'(?i)(?s)...'). In verbose mode whitespaces andcomments now are allowed before and between inline modifiers (e.g.'(?x)(?i)(?s)...').

bpo-29990: Fix range checking in GB18030 decoder. Original patch by MaLin.

bpo-26293: Change resulted because of zipfile breakage. (See also:bpo-29094)

bpo-30243: Removed the __init__ methods of _json’s scanner and encoder.Misusing them could cause memory leaks or crashes. Now scanner andencoder objects are completely initialized in the __new__ methods.

bpo-30185: Avoid KeyboardInterrupt tracebacks in forkserver helper processwhen Ctrl-C is received.

bpo-28556: Various updates to typing module: add typing.NoReturn type, useWrapperDescriptorType, minor bug-fixes. Original PRs by JimFasarakis-Hilliard and Ivan Levkivskyi.

bpo-30205: Fix getsockname() for unbound AF_UNIX sockets on Linux.

bpo-30070: Fixed leaks and crashes in errors handling in the parsermodule.

bpo-30061: Fixed crashes in IOBase methods __next__() and readlines() whenreadline() or __next__() respectively return non-sizeable object. Fixedpossible other errors caused by not checking results of PyObject_Size(),PySequence_Size(), or PyMapping_Size().

bpo-30017: Allowed calling the close() method of the zip entry writerobject multiple times. Writing to a closed writer now always produces aValueError.

bpo-30068: _io._IOBase.readlines will check if it’s closed first when hintis present.

bpo-29694: Fixed race condition in pathlib mkdir with flags parents=True.Patch by Armin Rigo.

bpo-29692: Fixed arbitrary unchaining of RuntimeError exceptions incontextlib.contextmanager. Patch by Siddharth Velankar.

bpo-29998: Pickling and copying ImportError now preserves name and pathattributes.

bpo-29953: Fixed memory leaks in the replace() method of datetime and timeobjects when pass out of bound fold argument.

bpo-29942: Fix a crash in itertools.chain.from_iterable when encounteringlong runs of empty iterables.

bpo-27863: Fixed multiple crashes in ElementTree caused by race conditionsand wrong types.

bpo-28699: Fixed a bug in pools in multiprocessing.pool that raising anexception at the very first of an iterable may swallow the exception ormake the program hang. Patch by Davin Potts and Xiang Zhang.

bpo-25803: Avoid incorrect errors raised by Path.mkdir(exist_ok=True) whenthe OS gives priority to errors such as EACCES over EEXIST.

bpo-29861: Release references to tasks, their arguments and their resultsas soon as they are finished in multiprocessing.Pool.

bpo-29884: faulthandler: Restore the old sigaltstack during teardown.Patch by Christophe Zeitouny.

bpo-25455: Fixed crashes in repr of recursive buffered file-like objects.

bpo-29800: Fix crashes in partial.__repr__ if the keys of partial.keywordsare not strings. Patch by Michael Seifert.

bpo-29742: get_extra_info() raises exception if get called on closed ssltransport. Patch by Nikolay Kim.

bpo-8256: Fixed possible failing or crashing input() if attributes“encoding” or “errors” of sys.stdin or sys.stdout are not set or are notstrings.

bpo-28298: Fix a bug that prevented array ‘Q’, ‘L’ and ‘I’ from acceptingbig intables (objects that have __int__) as elements. Patch by OrenMilman.

bpo-28231: The zipfile module now accepts path-like objects for externalpaths.

bpo-26915: index() and count() methods of collections.abc.Sequence nowcheck identity before checking equality when do comparisons.

bpo-29615: SimpleXMLRPCDispatcher no longer chains KeyError (or any otherexception) to exception(s) raised in the dispatched methods. Patch by PetrMotejlek.

bpo-30177: path.resolve(strict=False) no longer cuts the path after thefirst element not present in the filesystem. Patch by Antoine Pietri.

bpo-15786: Fix several problems with IDLE’s autocompletion box. Thefollowing should now work: clicking on selection box items; using thescrollbar; selecting an item by hitting Return. Hangs on MacOSX should nolonger happen. Patch by Louie Lu.

bpo-25514: Add doc subsubsection about IDLE failure to start. Popupno-connection message directs users to this section.

bpo-30642: Fix reference leaks in IDLE tests. Patches by Louie Lu andTerry Jan Reedy.

bpo-30495: Add docstrings for textview.py and use PEP8 names. Patches byCheryl Sabella and Terry Jan Reedy.

bpo-30290: Help-about: use pep8 names and add tests. Increase coverage to100%. Patches by Louie Lu, Cheryl Sabella, and Terry Jan Reedy.

bpo-30303: Add _utest option to textview; add new tests. Increase coverageto 100%. Patches by Louie Lu and Terry Jan Reedy.

bpo-27867: Function PySlice_GetIndicesEx() no longer replaced with a macroif Py_LIMITED_API is not set.

bpo-29941: Add--with-assertions configure flag to explicitly enable Cassert() checks. Defaults to off.--with-pydebug implies--with-assertions.

bpo-28787: Fix out-of-tree builds of Python when configured with--with--dtrace.

bpo-29243: Prevent unnecessary rebuilding of Python duringmaketest,makeinstall and some other make targets when configured with--enable-optimizations.

bpo-23404: Don’t regenerate generated files based on file modificationtime anymore: the action is now explicit. Replacemaketouch withmakeregen-all.

bpo-29643: Fix--enable-optimization didn’t work.

bpo-30176: Add missing attribute related constants in cursesdocumentation.

bpo-30052: the link targets forbytes() andbytearray() arenow their respective type definitions, rather than the correspondingbuiltin function entries. Usebytes andbytearray to reference the latter.

In order to ensure this and future cross-reference updates are appliedautomatically, the daily documentation builds now disable the defaultoutput caching features in Sphinx.

bpo-26985: Add missing info of code object in inspect documentation.

bpo-29367: python-gdb.py now supports alsomethod-wrapper(wrapperobject) objects.

bpo-30357: test_thread: setUp() now uses support.threading_setup() andsupport.threading_cleanup() to wait until threads complete to avoid randomside effects on following tests. Initial patch written by GrzegorzGrzywacz.

bpo-30197: Enhanced functions swap_attr() and swap_item() in thetest.support module. They now work when delete replaced attribute or iteminside the with statement. The old value of the attribute or item (orNone if it doesn’t exist) now will be assigned to the target of the “as”clause, if there is one.

bpo-30687: Locate msbuild.exe on Windows when building rather thanvcvarsall.bat

bpo-30450: The build process on Windows no longer depends on Subversion,instead pulling external code from GitHub via a Python script. If Python3.6 is not found on the system (viapy-3.6), NuGet is used todownload a copy of 32-bit Python.

bpo-29723: Thesys.path[0] initialization change forbpo-29139 causeda regression by revealing an inconsistency in how sys.path is initializedwhen executing__main__ from a zipfile, directory, or other importlocation. The interpreter now consistently avoids ever adding the importlocation’s parent directory tosys.path, and ensures no othersys.path entries are inadvertently modified when inserting the importlocation named on the command line.

bpo-27593: fix format of git information used in sys.version

Fix incompatible comment in python.h

bpo-28893: Set correct __cause__ for errors about invalid awaitablesreturned from __aiter__ and __anext__.

bpo-29683: Fixes to memory allocation in _PyCode_SetExtra. Patch by BrianColeman.

bpo-29684: Fix minor regression of PyEval_CallObjectWithKeywords. Itshould raise TypeError when kwargs is not a dict. But it might cause segvwhen args=NULL and kwargs is not a dict.

bpo-28598: Support __rmod__ for subclasses of str being called beforestr.__mod__. Patch by Martijn Pieters.

bpo-29607: Fix stack_effect computation for CALL_FUNCTION_EX. Patch byMatthieu Dartiailh.

bpo-29602: Fix incorrect handling of signed zeros in complex constructorfor complex subclasses and for inputs having a __complex__ method. Patchby Serhiy Storchaka.

bpo-29347: Fixed possibly dereferencing undefined pointers when creatingweakref objects.

bpo-29438: Fixed use-after-free problem in key sharing dict.

bpo-29319: Prevent RunMainFromImporter overwriting sys.path[0].

bpo-29337: Fixed possible BytesWarning when compare the code objects.Warnings could be emitted at compile time.

bpo-29327: Fixed a crash when pass the iterable keyword argument tosorted().

bpo-29034: Fix memory leak and use-after-free in os module(path_converter).

bpo-29159: Fix regression in bytes(x) when x.__index__() raises Exception.

bpo-28932: Do not include <sys/random.h> if it does not exist.

bpo-25677: Correct the positioning of the syntax error caret for indentedblocks. Based on patch by Michael Layzell.

bpo-29000: Fixed bytes formatting of octals with zero padding in alternateform.

bpo-26919: On Android, operating system data is now always encoded/decodedto/from UTF-8, instead of the locale encoding to avoid inconsistencieswith os.fsencode() and os.fsdecode() which are already using UTF-8.

bpo-28991: functools.lru_cache() was susceptible to an obscure reentrancybug triggerable by a monkey-patched len() function.

bpo-28739: f-string expressions are no longer accepted as docstrings andby ast.literal_eval() even if they do not include expressions.

bpo-28512: Fixed setting the offset attribute of SyntaxError byPyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().

bpo-28918: Fix the cross compilation of xxlimited when Python has beenbuilt with Py_DEBUG defined.

bpo-28731: Optimize _PyDict_NewPresized() to create correct size dict.Improve speed of dict literal with constant keys up to 30%.

bpo-29169: Update zlib to 1.2.11.

bpo-29623: Allow use of path-like object as a single argument inConfigParser.read(). Patch by David Ellis.

bpo-28963: Fix out of bound iteration inasyncio.Future.remove_done_callback implemented in C.

bpo-29704: asyncio.subprocess.SubprocessStreamProtocol no longer closesbefore all pipes are closed.

bpo-29271: Fix Task.current_task and Task.all_tasks implemented in C toaccept None argument as their pure Python implementation.

bpo-29703: Fix asyncio to support instantiation of new event loops inchild processes.

bpo-29376: Fix assertion error in threading._DummyThread.is_alive().

bpo-28624: Add a test that checks that cwd parameter of Popen() acceptsPathLike objects. Patch by Sayan Chowdhury.

bpo-28518: Start a transaction implicitly before a DML statement. Patch byAviv Palivoda.

bpo-29532: Altering a kwarg dictionary passed to functools.partial() nolonger affects a partial object after creation.

bpo-29110: Fix file object leak in aifc.open() when file is given as afilesystem path and is not in valid AIFF format. Patch by Anthony Zhang.

bpo-28556: Various updates to typing module: typing.Counter,typing.ChainMap, improved ABC caching, etc. Original PRs by JelleZijlstra, Ivan Levkivskyi, Manuel Krebber, and Łukasz Langa.

bpo-29100: Fix datetime.fromtimestamp() regression introduced in Python3.6.0: check minimum and maximum years.

bpo-29519: Fix weakref spewing exceptions during interpreter shutdown whenused with a rare combination of multiprocessing and custom codecs.

bpo-29416: Prevent infinite loop in pathlib.Path.mkdir

bpo-29444: Fixed out-of-bounds buffer access in the group() method of thematch object. Based on patch by WGH.

bpo-29335: Fix subprocess.Popen.wait() when the child process has exitedto a stopped instead of terminated state (ex: when under ptrace).

bpo-29290: Fix a regression in argparse that help messages would wrap atnon-breaking spaces.

bpo-28735: Fixed the comparison of mock.MagickMock with mock.ANY.

bpo-29316: Restore the provisional status of typing module, addcorresponding note to documentation. Patch by Ivan L.

bpo-29219: Fixed infinite recursion in the repr of uninitializedctypes.CDLL instances.

bpo-29011: Fix an important omission by adding Deque to the typing module.

bpo-28969: Fixed race condition in C implementation offunctools.lru_cache. KeyError could be raised when cached function withfull cache was simultaneously called from differen threads with the sameuncached arguments.

bpo-29142: In urllib.request, suffixes in no_proxy environment variablewith leading dots could match related hostnames again (e.g. .b.c matchesa.b.c). Patch by Milan Oberkirch.

bpo-28961: Fix unittest.mock._Call helper: don’t ignore the name parameteranymore. Patch written by Jiajun Huang.

bpo-29203: functools.lru_cache() now respects PEP 468 and preserves theorder of keyword arguments. f(a=1, b=2) is now cached separately fromf(b=2, a=1) since both calls could potentially give different results.

bpo-15812: inspect.getframeinfo() now correctly shows the first line of acontext. Patch by Sam Breese.

bpo-29094: Offsets in a ZIP file created with extern file object and modes“w” and “x” now are relative to the start of the file.

bpo-29085: Allow random.Random.seed() to use high quality OS randomnessrather than the pid and time.

bpo-29061: Fixed bug in secrets.randbelow() which would hang when given anegative input. Patch by Brendan Donegan.

bpo-29079: Prevent infinite loop in pathlib.resolve() on Windows

bpo-13051: Fixed recursion errors in large or resizedcurses.textpad.Textbox. Based on patch by Tycho Andersen.

bpo-29119: Fix weakrefs in the pure python version ofcollections.OrderedDict move_to_end() method. Contributed by AndraBogildea.

bpo-9770: curses.ascii predicates now work correctly with negativeintegers.

bpo-28427: old keys should not remove new values from WeakValueDictionarywhen collecting from another thread.

bpo-28923: Remove editor artifacts from Tix.py.

bpo-29055: Neaten-up empty population error on random.choice() bysuppressing the upstream exception.

bpo-28871: Fixed a crash when deallocate deep ElementTree.

bpo-19542: Fix bugs in WeakValueDictionary.setdefault() andWeakValueDictionary.pop() when a GC collection happens in another thread.

bpo-20191: Fixed a crash in resource.prlimit() when passing a sequencethat doesn’t own its elements as limits.

bpo-28779: multiprocessing.set_forkserver_preload() would crash theforkserver process if a preloaded module instantiated some multiprocessingobjects such as locks.

bpo-28847: dbm.dumb now supports reading read-only files and no longerwrites the index file when it is not changed.

bpo-26937: The chown() method of the tarfile.TarFile class does not failnow when the grp module cannot be imported, as for example on Androidplatforms.

bpo-29071: IDLE colors f-string prefixes (but not invalid ur prefixes).

bpo-28572: Add 10% to coverage of IDLE’s test_configdialog. Update andaugment description of the configuration system.

bpo-29579: Removes readme.txt from the installer

bpo-29326: Ignores blank lines in ._pth files (Patch by Alexey Izbyshev)

bpo-28164: Correctly handle special console filenames (patch by Eryk Sun)

bpo-29409: Implement PEP 529 for io.FileIO (Patch by Eryk Sun)

bpo-29392: Prevent crash when passing invalid arguments into msvcrtmodule.

bpo-25778: winreg does not truncate string correctly (Patch by Eryk Sun)

bpo-28896: Deprecate WindowsRegistryFinder and disable it by default.

bpo-27867: Function PySlice_GetIndicesEx() is replaced with a macro ifPy_LIMITED_API is not set or set to the value between 0x03050400 and0x03060000 (not including) or 0x03060100 or higher.

bpo-29083: Fixed the declaration of some public API functions.PyArg_VaParse() and PyArg_VaParseTupleAndKeywords() were not available inlimited API. PyArg_ValidateKeywordArguments(), PyArg_UnpackTuple() andPy_BuildValue() were not available in limited API of version < 3.3 whenPY_SSIZE_T_CLEAN is defined.

bpo-29058: All stable API extensions added after Python 3.2 are nowavailable only when Py_LIMITED_API is set to the PY_VERSION_HEX value ofthe minimum Python version supporting this API.

bpo-28929: Link the documentation to its source file on GitHub.

bpo-25008: Document smtpd.py as effectively deprecated and add a pointerto aiosmtpd, a third-party asyncio-based replacement.

bpo-26355: Add canonical header link on each page to corresponding majorversion of the documentation. Patch by Matthias Bussonnier.

bpo-29349: Fix Python 2 syntax in code for building the documentation.

bpo-28087: Skip test_asyncore and test_eintr poll failures on macOS. Skipsome tests of select.poll when running on macOS due to unresolved issueswith the underlying system poll function on some macOS versions.

bpo-29571: to match the behaviour of there.LOCALE flag,test_re.test_locale_flag now useslocale.getpreferredencoding(False)to determine the candidate encoding for the test regex (allowing it tocorrectly skip the test when the default locale encoding is a multi-byteencoding)

bpo-28950: Disallow -j0 to be combined with -T/-l in regrtest command linearguments.

bpo-28683: Fix the tests that bind() a unix socket and raisePermissionError on Android for a non-root user.

bpo-26939: Add the support.setswitchinterval() function to fixtest_functools hanging on the Android armv7 qemu emulator.

bpo-27593: sys.version and the platform module python_build(),python_branch(), and python_revision() functions now use git informationrather than hg when building from a repo.

bpo-29572: Update Windows build and OS X installers to use OpenSSL 1.0.2k.

bpo-26851: Set Android compilation and link flags.

bpo-28768: Fix implicit declaration of function _setmode. Patch byMasayuki Yamamoto

bpo-29080: Removes hard dependency on hg.exe from PCBuild/build.bat

bpo-23903: Added missed names to PC/python3.def.

bpo-28762: lockf() is available on Android API level 24, but the F_LOCKmacro is not defined in android-ndk-r13.

bpo-28538: Fix the compilation error that occurs because if_nameindex() isavailable on Android API level 24, but the if_nameindex structure is notdefined.

bpo-20211: Do not add the directory for installing C header files and thedirectory for installing object code libraries to the cross compilationsearch paths. Original patch by Thomas Petazzoni.

bpo-28849: Do not define sys.implementation._multiarch on Android.

bpo-28147: Fix a memory leak in split-table dictionaries: setattr() mustnot convert combined table into split table. Patch written by INADA Naoki.

bpo-28990: Fix asyncio SSL hanging if connection is closed beforehandshake is completed. (Patch by HoHo-Ho)

bpo-28770: Fix python-gdb.py for fastcalls.

bpo-28896: Deprecate WindowsRegistryFinder.

bpo-28898: Prevent gdb build errors due to HAVE_LONG_LONG redefinition.

bpo-23722: Rather than silently producing a class that doesn’t supportzero-argumentsuper() in methods, failing to pass the new__classcell__ namespace entry up totype.__new__ now results in aDeprecationWarning and a class that supports zero-argumentsuper().

bpo-28797: Modifying the class __dict__ inside the __set_name__ method ofa descriptor that is used inside that class no longer prevents calling the__set_name__ method of other descriptors.

bpo-28782: Fix a bug in the implementationyieldfrom when checking ifthe next instruction is YIELD_FROM. Regression introduced by WORDCODE(bpo-26647).

bpo-27030: Unknown escapes in re.sub() replacement template are allowedagain. But they still are deprecated and will be disabled in 3.7.

bpo-28835: Fix a regression introduced in warnings.catch_warnings(): callwarnings.showwarning() if it was overriden inside the context manager.

bpo-27172: To assist with upgrades from 2.7, the previously documenteddeprecation ofinspect.getfullargspec() has been reversed. Thisdecision may be revisited again after the Python 2.7 branch is no longerofficially supported.

bpo-26273: Add newsocket.TCP_CONGESTION (Linux 2.6.13) andsocket.TCP_USER_TIMEOUT (Linux 2.6.37) constants. Patch written byOmar Sandoval.

bpo-24142: Reading a corrupt config file left configparser in an invalidstate. Original patch by Florian Höch.

bpo-28843: Fix asyncio C Task to handle exceptions __traceback__.

bpo-28808: PyUnicode_CompareWithASCIIString() now never raises exceptions.

bpo-23722: The data model reference and the porting section in the What’sNew guide now cover the additional__classcell__ handling needed forcustom metaclasses to fully support PEP 487 and zero-argumentsuper().

bpo-28023: Fix python-gdb.py didn’t support new dict implementation.

bpo-28532: Show sys.version when -V option is supplied twice.

bpo-27100: The with-statement now checks for __enter__ before it checksfor __exit__. This gives less confusing error messages when both methodsare missing. Patch by Jonathan Ellington.

bpo-28746: Fix the set_inheritable() file descriptor method on platformsthat do not have the ioctl FIOCLEX and FIONCLEX commands.

bpo-26920: Fix not getting the locale’s charset upon initializing theinterpreter, on platforms that do not have langinfo.

bpo-28648: Fixed crash in Py_DecodeLocale() in debug build on Mac OS Xwhen decode astral characters. Patch by Xiang Zhang.

bpo-19398: Extra slash no longer added to sys.path components in case ofempty compile-time PYTHONPATH components.

bpo-28665: Improve speed of the STORE_DEREF opcode by 40%.

bpo-28583: PyDict_SetDefault didn’t combine split table when needed. Patchby Xiang Zhang.

bpo-27243: Change PendingDeprecationWarning -> DeprecationWarning. As itwas agreed in the issue, __aiter__ returning an awaitable should result inPendingDeprecationWarning in 3.5 and in DeprecationWarning in 3.6.

bpo-26182: Fix a refleak in code that raises DeprecationWarning.

bpo-28721: Fix asynchronous generators aclose() and athrow() to handleStopAsyncIteration propagation properly.

bpo-28752: Restored the __reduce__() methods of datetime objects.

bpo-28727: Regular expression patterns, _sre.SRE_Pattern objects createdby re.compile(), become comparable (only x==y and x!=y operators). Thischange should fix thebpo-18383: don’t duplicate warning filters whenthe warnings module is reloaded (thing usually only done in unit tests).

bpo-20572: The subprocess.Popen.wait method’s undocumented endtimeparameter now raises a DeprecationWarning.

bpo-25659: In ctypes, prevent a crash calling the from_buffer() andfrom_buffer_copy() methods on abstract classes like Array.

bpo-19717: Makes Path.resolve() succeed on paths that do not exist. Patchby Vajrasky Kok

bpo-28563: Fixed possible DoS and arbitrary code execution when handleplural form selections in the gettext module. The expression parser nowsupports exact syntax supported by GNU gettext.

bpo-28387: Fixed possible crash in _io.TextIOWrapper deallocator when thegarbage collector is invoked in other thread. Based on patch by SebastianCufre.

bpo-28600: Optimize loop.call_soon.

bpo-28613: Fix get_event_loop() return the current loop if called fromcoroutines/callbacks.

bpo-28634: Fix asyncio.isfuture() to support unittest.Mock.

bpo-26081: Fix refleak in _asyncio.Future.__iter__().throw.

bpo-28639: Fix inspect.isawaitable to always return bool Patch by JustinMayfield.

bpo-28652: Make loop methods reject socket kinds they do not support.

bpo-28653: Fix a refleak in functools.lru_cache.

bpo-28703: Fix asyncio.iscoroutinefunction to handle Mock objects.

bpo-28704: Fix create_unix_server to support Path-like objects (PEP 519).

bpo-28720: Add collections.abc.AsyncGenerator.

bpo-28513: Documented command-line interface of zipfile.

bpo-28666: Now test.support.rmtree is able to remove unwritable orunreadable directories.

bpo-23839: Various caches now are cleared before running every test file.

bpo-10656: Fix out-of-tree building on AIX. Patch by Tristan Carel andMichael Haubenwallner.

bpo-26359: Rename –with-optimiations to –enable-optimizations.

bpo-28676: Prevent missing ‘getentropy’ declaration warning on macOS.Patch by Gareth Rees.

bpo-28128: Deprecation warning for invalid str and byte escape sequencesnow prints better information about where the error occurs. Patch bySerhiy Storchaka and Eric Smith.

bpo-28509: dict.update() no longer allocate unnecessary large memory.

bpo-28426: Fixed potential crash in PyUnicode_AsDecodedObject() in debugbuild.

bpo-28517: Fixed of-by-one error in the peephole optimizer that causedkeeping unreachable code.

bpo-28214: Improved exception reporting for problematic __set_name__attributes.

bpo-23782: Fixed possible memory leak in _PyTraceback_Add() and exceptionloss in PyTraceBack_Here().

bpo-28471: Fix “Python memory allocator called without holding the GIL”crash in socket.setblocking.

bpo-27517: LZMA compressor and decompressor no longer raise exceptions ifgiven empty data twice. Patch by Benjamin Fogle.

bpo-28549: Fixed segfault in curses’s addch() with ncurses6.

bpo-28449: tarfile.open() with mode “r” or “r:” now tries to open a tarfile with compression before trying to open it without compression.Otherwise it had 50% chance failed with ignore_zeros=True.

bpo-23262: The webbrowser module now supports Firefox 36+ and derivedbrowsers. Based on patch by Oleg Broytman.

bpo-27939: Fixed bugs in tkinter.ttk.LabeledScale and tkinter.Scale causedby representing the scale as float value internally in Tk. tkinter.IntVarnow works if float value is set to underlying Tk variable.

bpo-18844: The various ways of specifying weights for random.choices() nowproduce the same result sequences.

bpo-28255: calendar.TextCalendar().prmonth() no longer prints a space atthe start of new line after printing a month’s calendar. Patch by XiangZhang.

bpo-20491: The textwrap.TextWrapper class now honors non-breaking spaces.Based on patch by Kaarle Ritvanen.

bpo-28353: os.fwalk() no longer fails on broken links.

bpo-28430: Fix iterator of C implemented asyncio.Future doesn’t acceptnon-None value is passed to it.send(val).

bpo-27025: Generated names for Tkinter widgets now start by the “!” prefixfor readability.

bpo-25464: Fixed HList.header_exists() in tkinter.tix module by addin aworkaround to Tix library bug.

bpo-28488: shutil.make_archive() no longer adds entry “./” to ZIP archive.

bpo-25953: re.sub() now raises an error for invalid numerical groupreference in replacement template even if the pattern is not found in thestring. Error message for invalid group reference now includes the groupindex and the position of the reference. Based on patch by SilentGhost.

bpo-18219: Optimize csv.DictWriter for large number of columns. Patch byMariatta Wijaya.

bpo-28448: Fix C implemented asyncio.Future didn’t work on Windows.

bpo-28480: Fix error building socket module when multithreading isdisabled.

bpo-24452: Make webbrowser support Chrome on Mac OS X.

bpo-20766: Fix references leaked by pdb in the handling of SIGINThandlers.

bpo-28492: Fix how StopIteration exception is raised in _asyncio.Future.

bpo-28500: Fix asyncio to handle async gens GC from another thread.

bpo-26923: Fix asyncio.Gather to refuse being cancelled once all childrenare done. Patch by Johannes Ebke.

bpo-26796: Don’t configure the number of workers for default threadpoolexecutor. Initial patch by Hans Lawrenz.

bpo-28544: Implement asyncio.Task in C.

bpo-28522: Fixes mishandled buffer reallocation in getpathp.c

bpo-28444: Fix missing extensions modules when cross compiling.

bpo-28208: Update Windows build and OS X installers to use SQLite 3.14.2.

bpo-28248: Update Windows build and OS X installers to use OpenSSL 1.0.2j.

bpo-26944: Fix test_posix for Android where ‘id -G’ is entirely wrong ormissing the effective gid.

bpo-28409: regrtest: fix the parser of command line arguments.

bpo-28183: Optimize and cleanup dict iteration.

bpo-26081: Added C implementation of asyncio.Future. Original patch byYury Selivanov.

bpo-28379: Added sanity checks and tests for PyUnicode_CopyCharacters().Patch by Xiang Zhang.

bpo-28376: The type of long range iterator is now registered as Iterator.Patch by Oren Milman.

bpo-28376: Creating instances of range_iterator by calling range_iteratortype now is deprecated. Patch by Oren Milman.

bpo-28376: The constructor of range_iterator now checks that step is not0. Patch by Oren Milman.

bpo-26906: Resolving special methods of uninitialized type now causesimplicit initialization of the type instead of a fail.

bpo-18287: PyType_Ready() now checks that tp_name is not NULL. Originalpatch by Niklas Koep.

bpo-24098: Fixed possible crash when AST is changed in process ofcompiling it.

bpo-28201: Dict reduces possibility of 2nd conflict in hash table whenhashes have same lower bits.

bpo-28350: String constants with null character no longer interned.

bpo-26617: Fix crash when GC runs during weakref callbacks.

bpo-27942: String constants now interned recursively in tuples andfrozensets.

bpo-21578: Fixed misleading error message when ImportError called withinvalid keyword args.

bpo-28203: Fix incorrect type in complex(1.0, {2:3}) error message. Patchby Soumya Sharma.

bpo-28086: Single var-positional argument of tuple subtype was passedunscathed to the C-defined function. Now it is converted to exact tuple.

bpo-28214: Now __set_name__ is looked up on the class instead of theinstance.

bpo-27955: Fallback on reading /dev/urandom device when the getrandom()syscall fails with EPERM, for example when blocked by SECCOMP.

bpo-28192: Don’t import readline in isolated mode.

Upgrade internal unicode databases to Unicode version 9.0.0.

bpo-28131: Fix a regression in zipimport’s compile_source(). zipimportshould use the same optimization level as the interpreter.

bpo-28126: Replace Py_MEMCPY with memcpy(). Visual Studio can properlyoptimize memcpy().

bpo-28120: Fix dict.pop() for splitted dictionary when trying to remove a“pending key” (Not yet inserted in split-table). Patch by Xiang Zhang.

bpo-26182: Raise DeprecationWarning when async and await keywords are usedas variable/attribute/class/function name.

bpo-27998: Fixed bytes path support in os.scandir() on Windows. Patch byEryk Sun.

bpo-28317: The disassembler now decodes FORMAT_VALUE argument.

bpo-26293: Fixed writing ZIP files that starts not from the start of thefile. Offsets in ZIP file now are relative to the start of the archive inconforming to the specification.

bpo-28380: unittest.mock Mock autospec functions now properly supportassert_called, assert_not_called, and assert_called_once.

bpo-27181: remove statistics.geometric_mean and defer until 3.7.

bpo-28229: lzma module now supports pathlib.

bpo-28321: Fixed writing non-BMP characters with binary format inplistlib.

bpo-28225: bz2 module now supports pathlib. Initial patch by EthanFurman.

bpo-28227: gzip now supports pathlib. Patch by Ethan Furman.

bpo-27358: Optimized merging var-keyword arguments and improved errormessage when passing a non-mapping as a var-keyword argument.

bpo-28257: Improved error message when passing a non-iterable as avar-positional argument. Added opcode BUILD_TUPLE_UNPACK_WITH_CALL.

bpo-28322: Fixed possible crashes when unpickle itertools objects fromincorrect pickle data. Based on patch by John Leitch.

bpo-28228: imghdr now supports pathlib.

bpo-28226: compileall now supports pathlib.

bpo-28314: Fix function declaration (C flags) for the getiterator() methodof xml.etree.ElementTree.Element.

bpo-28148: Stop using localtime() and gmtime() in the time module.

Introduced platform independent _PyTime_localtime API that is similar toPOSIX localtime_r, but available on all platforms. Patch by Ed Schouten.

bpo-28253: Fixed calendar functions for extreme months: 0001-01 and9999-12.

Methods itermonthdays() and itermonthdays2() are reimplemented so thatthey don’t call itermonthdates() which can cause datetime.dateunder/overflow.

bpo-28275: Fixed possible use after free in the decompress() methods ofthe LZMADecompressor and BZ2Decompressor classes. Original patch by JohnLeitch.

bpo-27897: Fixed possible crash in sqlite3.Connection.create_collation()if pass invalid string-like object as a name. Patch by Xiang Zhang.

bpo-18844: random.choices() now has k as a keyword-only argument toimprove the readability of common cases and come into line with thesignature used in other languages.

bpo-18893: Fix invalid exception handling in Lib/ctypes/macholib/dyld.py.Patch by Madison May.

bpo-27611: Fixed support of default root window in the tkinter.tix module.Added the master parameter in the DisplayStyle constructor.

bpo-27348: In the traceback module, restore the formatting of exceptionmessages like “Exception: None”. This fixes a regression introduced in3.5a2.

bpo-25651: Allow falsy values to be used for msg parameter of subTest().

bpo-27778: Fix a memory leak in os.getrandom() when the getrandom() isinterrupted by a signal and a signal handler raises a Python exception.

bpo-28200: Fix memory leak on Windows in the os module (fixpath_converter() function).

bpo-25400: RobotFileParser now correctly returns default values forcrawl_delay and request_rate. Initial patch by Peter Wirtz.

bpo-27932: Prevent memory leak in win32_ver().

Fix UnboundLocalError in socket._sendfile_use_sendfile.

bpo-28075: Check for ERROR_ACCESS_DENIED in Windows implementation ofos.stat(). Patch by Eryk Sun.

bpo-22493: Warning message emitted by using inline flags in the middle ofregular expression now contains a (truncated) regex pattern. Patch by TimGraham.

bpo-25270: Prevent codecs.escape_encode() from raising SystemError when anempty bytestring is passed.

bpo-28181: Get antigravity over HTTPS. Patch by Kaartic Sivaraam.

bpo-25895: Enable WebSocket URL schemes in urllib.parse.urljoin. Patch byGergely Imreh and Markus Holtermann.

bpo-28114: Fix a crash in parse_envlist() when env contains byte strings.Patch by Eryk Sun.

bpo-27599: Fixed buffer overrun in binascii.b2a_qp() andbinascii.a2b_qp().

bpo-27906: Fix socket accept exhaustion during high TCP traffic. Patch byKevin Conway.

bpo-28174: Handle when SO_REUSEPORT isn’t properly supported. Patch bySeth Michael Larson.

bpo-26654: Inspect functools.partial in asyncio.Handle.__repr__. Patch byiceboy.

bpo-26909: Fix slow pipes IO in asyncio. Patch by INADA Naoki.

bpo-28176: Fix callbacks race in asyncio.SelectorLoop.sock_connect.

bpo-27759: Fix selectors incorrectly retain invalid file descriptors.Patch by Mark Williams.

bpo-28368: Refuse monitoring processes if the child watcher has no loopattached. Patch by Vincent Michel.

bpo-28369: Raise RuntimeError when transport’s FD is used with add_reader,add_writer, etc.

bpo-28370: Speedup asyncio.StreamReader.readexactly. Patch by КоренбергМарк.

bpo-28371: Deprecate passing asyncio.Handles to run_in_executor.

bpo-28372: Fix asyncio to support formatting of non-python coroutines.

bpo-28399: Remove UNIX socket from FS before binding. Patch by КоренбергМарк.

bpo-27972: Prohibit Tasks to await on themselves.

bpo-28402: Adds signed catalog files for stdlib on Windows.

bpo-28333: Enables Unicode for ps1/ps2 and input() prompts. (Patch by ErykSun)

bpo-28251: Improvements to help manuals on Windows.

bpo-28110: launcher.msi has different product codes between 32-bit and64-bit

bpo-28161: Opening CON for write access fails

bpo-28162: WindowsConsoleIO readall() fails if first line starts withCtrl+Z

bpo-28163: WindowsConsoleIO fileno() passes wrong flags to _open_osfhandle

bpo-28164: _PyIO_get_console_type fails for various paths

bpo-28137: Renames Windows path file to ._pth

bpo-28138: Windows ._pth file should allow import site

bpo-28426: Deprecated undocumented functions PyUnicode_AsEncodedObject(),PyUnicode_AsDecodedObject(), PyUnicode_AsDecodedUnicode() andPyUnicode_AsEncodedUnicode().

bpo-28258: Fixed build with Estonian locale (python-config and distcleantargets in Makefile). Patch by Arfrever Frehtes Taifersar Arahesis.

bpo-26661: setup.py now detects system libffi with multiarch wrapper.

bpo-15819: Remove redundant include search directory option for buildingoutside the source tree.

bpo-28217: Adds _testconsole module to test console input.

bpo-23722: The __class__ cell used by zero-argument super() is nowinitialized from type.__new__ rather than __build_class__, so classmethods relying on that will now work correctly when called from metaclassmethods during class creation. Patch by Martin Teichmann.

bpo-25221: Fix corrupted result from PyLong_FromLong(0) when Python iscompiled with NSMALLPOSINTS = 0.

bpo-27080: Implement formatting support for PEP 515. Initial patch byChris Angelico.

bpo-27199: In tarfile, expose copyfileobj bufsize to improve throughput.Patch by Jason Fried.

bpo-27948: In f-strings, only allow backslashes inside the braces (wherethe expressions are). This is a breaking change from the 3.6 alphareleases, where backslashes are allowed anywhere in an f-string. Also,require that expressions inside f-strings be enclosed within literalbraces, and not escapes likef'\x7b"hi"\x7d'.

bpo-28046: Remove platform-specific directories from sys.path.

bpo-28071: Add early-out for differencing from an empty set.

bpo-25758: Prevents zipimport from unnecessarily encoding a filename(patch by Eryk Sun)

bpo-25856: The __module__ attribute of extension classes and functions nowis interned. This leads to more compact pickle data with protocol 4.

bpo-27213: Rework CALL_FUNCTION* opcodes to produce shorter and moreefficient bytecode. Patch by Demur Rumed, design by Serhiy Storchaka,reviewed by Serhiy Storchaka and Victor Stinner.

bpo-26331: Implement tokenizing support for PEP 515. Patch by GeorgBrandl.

bpo-27999: Make “global after use” a SyntaxError, and ditto for nonlocal.Patch by Ivan Levkivskyi.

bpo-28003: Implement PEP 525 – Asynchronous Generators.

bpo-27985: Implement PEP 526 – Syntax for Variable Annotations. Patch byIvan Levkivskyi.

bpo-26058: Add a new private version to the builtin dict type, incrementedat each dictionary creation and at each dictionary change. Implementationof the PEP 509.

bpo-27364: A backslash-character pair that is not a valid escape sequencenow generates a DeprecationWarning. Patch by Emanuel Barry.

bpo-27350:dict implementation is changed like PyPy. It is more compactand preserves insertion order. (Concept developed by Raymond Hettinger andpatch by Inada Naoki.)

bpo-27911: Remove unnecessary error checks inexec_builtin_or_dynamic().

bpo-27078: Added BUILD_STRING opcode. Optimized f-strings evaluation.

bpo-17884: Python now requires systems with inttypes.h and stdint.h

bpo-27961: Require platforms to supportlonglong. Python hasn’tcompiled withoutlonglong for years, so this is basically aformality.

bpo-27355: Removed support for Windows CE. It was never finished, andWindows CE is no longer a relevant platform for Python.

Implement PEP 523.

bpo-27870: A left shift of zero by a large integer no longer attempts toallocate large amounts of memory.

bpo-25402: In int-to-decimal-string conversion, improve the estimate ofthe intermediate memory required, and remove an unnecessarily strictoverflow check. Patch by Serhiy Storchaka.

bpo-27214: In long_invert, be more careful about modifying object returnedby long_add, and remove an unnecessary check for small longs. Thanks OrenMilman for analysis and patch.

bpo-27506: Support passing the bytes/bytearray.translate() “delete”argument by keyword.

bpo-27812: Properly clear out a generator’s frame’s backreference to thegenerator to prevent crashes in frame.clear().

bpo-27811: Fix a crash when a coroutine that has not been awaited isfinalized with warnings-as-errors enabled.

bpo-27587: Fix another issue found by PVS-Studio: Null pointer check afteruse of ‘def’ in _PyState_AddModule(). Initial patch by Christian Heimes.

bpo-27792: The modulo operation applied tobool and otherintsubclasses now always returns anint. Previously the return typedepended on the input values. Patch by Xiang Zhang.

bpo-26984: int() now always returns an instance of exact int.

bpo-25604: Fix a minor bug in integer true division; this bug couldpotentially have caused off-by-one-ulp results on platforms withunreliable ldexp implementations.

bpo-24254: Make class definition namespace ordered by default.

bpo-27662: Fix an overflow check inList_New: the original code waschecking againstPy_SIZE_MAX instead of the correct upper bound ofPy_SSIZE_T_MAX. Patch by Xiang Zhang.

bpo-27782: Multi-phase extension module import now correctly allows them_methods field to be used to add module level functions to instancesof non-module types returned fromPy_create_mod. Patch by Xiang Zhang.

bpo-27936: The round() function accepted a second None argument for sometypes but not for others. Fixed the inconsistency by accepting None forall numeric types.

bpo-27487: Warn if a submodule argument to “python -m” orrunpy.run_module() is found in sys.modules after parent packages areimported, but before the submodule is executed.

bpo-27157: Make only type() itself accept the one-argument form. Patch byEryk Sun and Emanuel Barry.

bpo-27558: Fix a SystemError in the implementation of “raise” statement.In a brand new thread, raise a RuntimeError since there is no activeexception to reraise. Patch written by Xiang Zhang.

bpo-28008: Implement PEP 530 – asynchronous comprehensions.

bpo-27942: Fix memory leak in codeobject.c

bpo-28732: Fix crash in os.spawnv() with no elements in args

bpo-28485: Always raise ValueError for negativecompileall.compile_dir(workers=…) parameter, even when multithreading isunavailable.

bpo-28037: Use sqlite3_get_autocommit() instead of settingConnection->inTransaction manually.

bpo-25283: Attributes tm_gmtoff and tm_zone are now available on allplatforms in the return values of time.localtime() and time.gmtime().

bpo-24454: Regular expression match object groups are now accessible using__getitem__. “mo[x]” is equivalent to “mo.group(x)”.

bpo-10740: sqlite3 no longer implicitly commit an open transaction beforeDDL statements.

bpo-17941: Add amodule parameter to collections.namedtuple().

bpo-22493: Inline flags now should be used only at the start of theregular expression. Deprecation warning is emitted if uses them in themiddle of the regular expression.

bpo-26885: xmlrpc now supports unmarshalling additional data types used byApache XML-RPC implementation for numerics and None.

bpo-28070: Fixed parsing inline verbose flag in regular expressions.

bpo-19500: Add client-side SSL session resumption to the ssl module.

bpo-28022: Deprecate ssl-related arguments in favor of SSLContext. Thedeprecation include manual creation of SSLSocket and certfile/keyfile (orsimilar) in ftplib, httplib, imaplib, smtplib, poplib and urllib.

bpo-28043: SSLContext has improved default settings: OP_NO_SSLv2,OP_NO_SSLv3, OP_NO_COMPRESSION, OP_CIPHER_SERVER_PREFERENCE,OP_SINGLE_DH_USE, OP_SINGLE_ECDH_USE and HIGH ciphers without MD5.

bpo-24693: Changed some RuntimeError’s in the zipfile module to moreappropriate types. Improved some error messages and debugging output.

bpo-17909:json.load andjson.loads now support binary inputencoded as UTF-8, UTF-16 or UTF-32. Patch by Serhiy Storchaka.

bpo-27137: the pure Python fallback implementation offunctools.partial now matches the behaviour of its accelerated Ccounterpart for subclassing, pickling and text representation purposes.Patch by Emanuel Barry and Serhiy Storchaka.

Fix possible integer overflows and crashes in the mmap module with unusualusage patterns.

bpo-1703178: Fix the ability to pass the –link-objects option to thedistutils build_ext command.

bpo-28019: itertools.count() no longer rounds non-integer step in rangebetween 1.0 and 2.0 to 1.

bpo-18401: Pdb now supports the ‘readrc’ keyword argument to controlwhether .pdbrc files should be read. Patch by Martin Matusiak and SamKimbrel.

bpo-25969: Update the lib2to3 grammar to handle the unpackinggeneralizations added in 3.5.

bpo-14977: mailcap now respects the order of the lines in the mailcapfiles (“first match”), as required by RFC 1542. Patch by Michael Lazar.

bpo-28082: Convert re flag constants to IntFlag.

bpo-28025: Convert all ssl module constants to IntEnum and IntFlags.SSLContext properties now return flags and enums.

bpo-23591: Add Flag, IntFlag, and auto() to enum module.

bpo-433028: Added support of modifier spans in regular expressions.

bpo-24594: Validates persist parameter when opening MSI database

bpo-17582: xml.etree.ElementTree nows preserves whitespaces in attributes(Patch by Duane Griffin. Reviewed and approved by Stefan Behnel.)

bpo-28047: Fixed calculation of line length used for the base64 CTE in thenew email policies.

bpo-27576: Fix call order in OrderedDict.__init__().

email.generator.DecodedGenerator now supports the policy keyword.

bpo-28027: Remove undocumented modules fromLib/plat-*: IN, CDROM,DLFCN, TYPES, CDIO, and STROPTS.

bpo-27445: Don’t pass str(_charset) to MIMEText.set_payload(). Patch byClaude Paroz.

bpo-24277: The new email API is no longer provisional, and the docs havebeen reorganized and rewritten to emphasize the new API.

bpo-22450: urllib now includes anAccept:*/* header among the defaultheaders. This makes the results of REST API requests more consistent andpredictable especially when proxy servers are involved.

lib2to3.pgen3.driver.load_grammar() now creates a stable cache filebetween runs given the same Grammar.txt input regardless of the hashrandomization setting.

bpo-28005: Allow ImportErrors in encoding implementation to propagate.

bpo-26667: Support path-like objects in importlib.util.

bpo-27570: Avoid zero-length memcpy() etc calls with null source pointersin the “ctypes” and “array” modules.

bpo-22233: Break email header linesonly on the RFC specified CR and LFcharacters, not on arbitrary unicode line breaks. This also fixes a bugin HTTP header parsing.

bpo-27331: The email.mime classes now all accept an optional policykeyword.

bpo-27988: Fix email iter_attachments incorrect mutation of payload list.

bpo-16113: Add SHA-3 and SHAKE support to hashlib module.

Eliminate a tautological-pointer-compare warning in _scproxy.c.

bpo-27776: Theos.urandom() function does now block on Linux 3.17and newer until the system urandom entropy pool is initialized to increasethe security. This change is part of thePEP 524.

bpo-27778: Expose the Linuxgetrandom() syscall as a newos.getrandom() function. This change is part of thePEP 524.

bpo-27691: Fix ssl module’s parsing of GEN_RID subject alternative namefields in X.509 certs.

bpo-18844: Add random.choices().

bpo-25761: Improved error reporting about truncated pickle data in Cimplementation of unpickler. UnpicklingError is now raised instead ofAttributeError and ValueError in some cases.

bpo-26798: Add BLAKE2 (blake2b and blake2s) to hashlib.

bpo-26032: Optimized globbing in pathlib by using os.scandir(); it is nowabout 1.5–4 times faster.

bpo-25596: Optimized glob() and iglob() functions in the glob module; theyare now about 3–6 times faster.

bpo-27928: Add scrypt (password-based key derivation function) to hashlibmodule (requires OpenSSL 1.1.0).

bpo-27850: Remove 3DES from ssl module’s default cipher list to countermeasure sweet32 attack (CVE-2016-2183).

bpo-27766: Add ChaCha20 Poly1305 to ssl module’s default cipher list.(Required OpenSSL 1.1.0 or LibreSSL).

bpo-25387: Check return value of winsound.MessageBeep.

bpo-27866: Add SSLContext.get_ciphers() method to get a list of allenabled ciphers.

bpo-27744: Add AF_ALG (Linux Kernel crypto) to socket module.

bpo-26470: Port ssl and hashlib module to OpenSSL 1.1.0.

bpo-11620: Fix support for SND_MEMORY in winsound.PlaySound. Based on apatch by Tim Lesher.

bpo-11734: Add support for IEEE 754 half-precision floats to the structmodule. Based on a patch by Eli Stevens.

bpo-27919: Deprecatedextra_path distribution option in distutilspackaging.

bpo-23229: Add newcmath constants:cmath.inf andcmath.nan tomatchmath.inf andmath.nan, and alsocmath.infj andcmath.nanj to match the format used by complex repr.

bpo-27842: The csv.DictReader now returns rows of type OrderedDict.(Contributed by Steve Holden.)

Remove support for passing a file descriptor to os.access. It never workedbut previously didn’t raise.

bpo-12885: Fix error when distutils encounters symlink.

bpo-27881: Fixed possible bugs when settingsqlite3.Connection.isolation_level. Based on patch by Xiang Zhang.

bpo-27861: Fixed a crash in sqlite3.Connection.cursor() when a factorycreates not a cursor. Patch by Xiang Zhang.

bpo-19884: Avoid spurious output on OS X with Gnu Readline.

bpo-27706: Restore deterministic behavior of random.Random().seed() forstring seeds using seeding version 1. Allows sequences of calls torandom() to exactly match those obtained in Python 2. Patch by NofarSchnider.

bpo-10513: Fix a regression in Connection.commit(). Statements should notbe reset after a commit.

bpo-12319: Chunked transfer encoding support added tohttp.client.HTTPConnection requests. Theurllib.request.AbstractHTTPHandler class does not enforce a Content-Lengthheader any more. If a HTTP request has a file or iterable body, but noContent-Length header, the library now falls back to use chunkedtransfer-encoding.

A new version of typing.py fromhttps://github.com/python/typing: -Collection (only for 3.6) (bpo-27598) - Add FrozenSet to __all__(upstream #261) - fix crash in _get_type_vars() (upstream #259) - Removethe dict constraint in ForwardRef._eval_type (upstream #252)

bpo-27832: Make_normalize parameter toFraction constuctorkeyword-only, so thatFraction(2,3,4) now raisesTypeError.

bpo-27539: Fix unnormalisedFraction.__pow__ result in the case ofnegative exponent and negative base.

bpo-21718: cursor.description is now available for queries using CTEs.

bpo-27819: In distutils sdists, simply produce the “gztar” (gzipped tarformat) distributions on all platforms unless “formats” is supplied.

bpo-2466: posixpath.ismount now correctly recognizes mount points whichthe user does not have permission to access.

bpo-9998: On Linux, ctypes.util.find_library now looks in LD_LIBRARY_PATHfor shared libraries.

bpo-27573: exit message for code.interact is now configurable.

bpo-27930: Improved behaviour of logging.handlers.QueueListener. Thanks toPaulo Andrade and Petr Viktorin for the analysis and patch.

bpo-6766: Distributed reference counting added to multiprocessing tosupport nesting of shared values / proxy objects.

bpo-21201: Improves readability of multiprocessing error message. Thanksto Wojciech Walczak for patch.

asyncio: Add set_protocol / get_protocol to Transports.

bpo-27456: asyncio: Set TCP_NODELAY by default.

bpo-15308: Add ‘interrupt execution’ (^C) to Shell menu. Patch by RogerSerwy, updated by Bayard Randel.

bpo-27922: Stop IDLE tests from ‘flashing’ gui widgets on the screen.

bpo-27891: Consistently group and sort imports within idlelib modules.

bpo-17642: add larger font sizes for classroom projection.

Add version to title of IDLE help window.

bpo-25564: In section on IDLE – console differences, mention that usingexec means that __builtins__ is defined for each statement.

bpo-27821: Fix 3.6.0a3 regression that prevented custom key sets frombeing selected when no custom theme was defined.

bpo-26900: Excluded underscored names and other private API from limitedAPI.

bpo-26027: Add support for path-like objects in PyUnicode_FSConverter() &PyUnicode_FSDecoder().

bpo-27427: Additional tests for the math module. Patch by Francisco Couzo.

bpo-27953: Skip math and cmath tests that fail on OS X 10.4 due to a poorlibm implementation of tan.

bpo-26040: Improve test_math and test_cmath coverage and rigour. Patch byJeff Allen.

bpo-27787: Call gc.collect() before checking each test for “danglingthreads”, since the dangling threads are weak references.

bpo-27566: Fix clean target in freeze makefile (patch by Lisa Roach)

bpo-27705: Update message in validate_ucrtbase.py

bpo-27976: Deprecate building _ctypes with the bundled copy of libffi onnon-OSX UNIX platforms.

bpo-27983: Cause lack of llvm-profdata tool when using clang as requiredfor PGO linking to be a configure time error rather than make time when--with-optimizations is enabled. Also improve our ability to find thellvm-profdata tool on MacOS and some Linuxes.

bpo-21590: Support for DTrace and SystemTap probes.

bpo-26307: The profile-opt build now applies PGO to the built-in modules.

bpo-26359: Add the –with-optimizations flag to turn on LTO and PGO buildsupport when available.

bpo-27917: Set platform triplets for Android builds.

bpo-25825: Update references to the $(LIBPL) installation path on AIX.This path was changed in 3.2a4.

Update OS X installer to use SQLite 3.14.1 and XZ 5.2.2.

bpo-21122: Fix LTO builds on OS X.

bpo-17128: Build OS X installer with a private copy of OpenSSL. Alsoprovide a sample Install Certificates command script to install a set ofroot certificates from the third-party certifi module.

bpo-27952: Get Tools/scripts/fixcid.py working with Python 3 and thecurrent “re” module, avoid invalid Python backslash escapes, and fix a bugparsing escaped C quote signs.

bpo-28065: Update xz dependency to 5.2.2 and build it from source.

bpo-25144: Ensures TargetDir is set before continuing with custom install.

bpo-1602: Windows console doesn’t input or print Unicode (PEP 528)

bpo-27781: Change file system encoding on Windows to UTF-8 (PEP 529)

bpo-27731: Opt-out of MAX_PATH on Windows 10

bpo-6135: Adds encoding and errors parameters to subprocess.

bpo-27959: Adds oem encoding, alias ansi to mbcs, move aliasmbcs to codeclookup.

bpo-27982: The functions of the winsound module now accept keywordarguments.

bpo-20366: Build full text search support into SQLite on Windows.

bpo-27756: Adds new icons for Python files and processes on Windows.Designs by Cherry Wang.

bpo-27883: Update sqlite to 3.14.1.0 on Windows.

bpo-27704: Optimized creating bytes and bytearray from byte-like objectsand iterables. Speed up to 3 times for short objects. Original patch byNaoki Inada.

bpo-26823: Large sections of repeated lines in tracebacks are nowabbreviated as “[Previous line repeated {count} more times]” by thebuiltin traceback rendering. Patch by Emanuel Barry.

bpo-27574: Decreased an overhead of parsing keyword arguments in functionsimplemented with using Argument Clinic.

bpo-22557: Now importing already imported modules is up to 2.5 timesfaster.

bpo-17596: Include <wincrypt.h> to help with Min GW building.

bpo-17599: On Windows, rename the privately defined REPARSE_DATA_BUFFERstructure to avoid conflicting with the definition from Min GW.

bpo-27507: Add integer overflow check in bytearray.extend(). Patch byXiang Zhang.

bpo-27581: Don’t rely on wrapping for overflow check inPySequence_Tuple(). Patch by Xiang Zhang.

bpo-1621: Avoid signed integer overflow in list and tuple operations.Patch by Xiang Zhang.

bpo-27419: Standard __import__() no longer look up “__import__” in globalsor builtins for importing submodules or “from import”. Fixed a crash ifraise a warning about unabling to resolve package from __spec__ or__package__.

bpo-27083: Respect the PYTHONCASEOK environment variable under Windows.

bpo-27514: Make having too many statically nested blocks a SyntaxErrorinstead of SystemError.

bpo-27366: Implemented PEP 487 (Simpler customization of class creation).Upon subclassing, the __init_subclass__ classmethod is called on the baseclass. Descriptors are initialized with __set_name__ after class creation.

bpo-26027: Add PEP 519/__fspath__() support to the os and os.path modules.Includes code from Jelle Zijlstra. (See also:bpo-27524)

bpo-27598: Add Collections to collections.abc. Patch by Ivan Levkivskyi,docs by Neil Girdhar.

bpo-25958: Support “anti-registration” of special methods from variousABCs, like __hash__, __iter__ or __len__. All these (and several more)can be set to None in an implementation class and the behavior will be asif the method is not defined at all. (Previously, this mechanism existedonly for __hash__, to make mutable classes unhashable.) Code contributedby Andrew Barnert and Ivan Levkivskyi.

bpo-16764: Support keyword arguments to zlib.decompress(). Patch by XiangZhang.

bpo-27736: Prevent segfault after interpreter re-initialization due to refcount problem introduced in code forbpo-27038 in 3.6.0a3. Patch byXiang Zhang.

bpo-25628: Theverbose andrename parameters forcollections.namedtuple are now keyword-only.

bpo-12345: Add mathematical constant tau to math and cmath. See also PEP628.

bpo-26823: traceback.StackSummary.format now abbreviates large sections ofrepeated lines as “[Previous line repeated {count} more times]” (thischange then further affects other traceback display operations in themodule). Patch by Emanuel Barry.

bpo-27664: Add to concurrent.futures.thread.ThreadPoolExecutor() theability to specify a thread name prefix.

bpo-27181: Add geometric_mean and harmonic_mean to statistics module.

bpo-27573: code.interact now prints an message when exiting.

bpo-6422: Add autorange method to timeit.Timer objects.

bpo-27773: Correct some memory management errors server_hostname in_ssl.wrap_socket().

bpo-26750: unittest.mock.create_autospec() now works properly forsubclasses of property() and other data descriptors. Removes the neverpublicly used, never documented unittest.mock.DescriptorTypes tuple.

bpo-26754: Undocumented support of general bytes-like objects as path incompile() and similar functions is now deprecated.

bpo-26800: Undocumented support of general bytes-like objects as paths inos functions is now deprecated.

bpo-26981: Add _order_ compatibility shim to enum.Enum for Python 2/3 codebases.

bpo-27661: Added tzinfo keyword argument to datetime.combine.

In the curses module, raise an error if window.getstr() or window.instr()is passed a negative value.

bpo-27783: Fix possible usage of uninitialized memory inoperator.methodcaller.

bpo-27774: Fix possible Py_DECREF on unowned object in _sre.

bpo-27760: Fix possible integer overflow in binascii.b2a_qp.

bpo-27758: Fix possible integer overflow in the _csv module for largerecord lengths.

bpo-27568: Prevent HTTPoxy attack (CVE-2016-1000110). Ignore theHTTP_PROXY variable when REQUEST_METHOD environment is set, whichindicates that the script is in CGI mode.

bpo-7063: Remove dead code from the “array” module’s slice handling. Patchby Chuck.

bpo-27656: Do not assume sched.h defines any SCHED_* constants.

bpo-27130: In the “zlib” module, fix handling of large buffers (typically4 GiB) when compressing and decompressing. Previously, inputs werelimited to 4 GiB, and compression and decompression operations did notproperly handle results of 4 GiB.

bpo-24773: Implemented PEP 495 (Local Time Disambiguation).

Expose the EPOLLEXCLUSIVE constant (when it is defined) in the selectmodule.

bpo-27567: Expose the EPOLLRDHUP and POLLRDHUP constants in the selectmodule.

bpo-1621: Avoid signed int negation overflow in the “audioop” module.

bpo-27533: Release GIL in nt._isdir

bpo-17711: Fixed unpickling by the persistent ID with protocol 0. Originalpatch by Alexandre Vassalotti.

bpo-27522: Avoid an unintentional reference cycle in email.feedparser.

bpo-27512: Fix a segfault when os.fspath() called an __fspath__() methodthat raised an exception. Patch by Xiang Zhang.

bpo-27714: text_textview and test_autocomplete now pass when re-run in thesame process. This occurs when test_idle fails when run with the -woption but without -jn. Fix warning from test_config.

bpo-27621: Put query response validation error messages in the query boxitself instead of in a separate messagebox. Redo tests to match. Add MacOSX refinements. Original patch by Mark Roseman.

bpo-27620: Escape key now closes Query box as cancelled.

bpo-27609: IDLE: tab after initial whitespace should tab, notautocomplete. This fixes problem with writing docstrings at least twiceindented.

bpo-27609: Explicitly return None when there are also non-None returns. Ina few cases, reverse a condition and eliminate a return.

bpo-25507: IDLE no longer runs buggy code because of its tkinter imports.Users must include the same imports required to run directly in Python.

bpo-27173: Add ‘IDLE Modern Unix’ to the built-in key sets. Make thedefault key set depend on the platform. Add tests for the changes to theconfig module.

bpo-27452: add line counter and crc to IDLE configHandler test dump.

bpo-25805: Skip a test in test_pkgutil as needed that doesn’t work when__name__==__main__. Patch by SilentGhost.

bpo-27472: Add test.support.unix_shell as the path to the default shell.

bpo-27369: In test_pyexpat, avoid testing an error message detail thatchanged in Expat 2.2.0.

bpo-27594: Prevent assertion error when running test_ast with coverageenabled: ensure code object has a valid first line number. Patch suggestedby Ivan Levkivskyi.

bpo-27647: Update bundled Tcl/Tk to 8.6.6.

bpo-27610: Adds PEP 514 metadata to Windows installer

bpo-27469: Adds a shell extension to the launcher so that drag and dropworks correctly.

bpo-27309: Enables proper Windows styles in python[w].exe manifest.

bpo-27713: Suppress spurious build warnings when updating importlib’sbootstrap files. Patch by Xiang Zhang

bpo-25825: Correct the references to Modules/python.exp, which is requiredon AIX. The references were accidentally changed in 3.5.0a1.

bpo-27453: CPP invocation in configure must use CPPFLAGS. Patch by ChiHsuan Yen.

bpo-27641: The configure script now inserts comments into the makefile toprevent the pgen and _freeze_importlib executables from beingcross-compiled.

bpo-26662: Set PYTHON_FOR_GEN in configure as the Python program to beused for file generation during the build.

bpo-10910: Avoid C++ compilation errors on FreeBSD and OS X. Also updateFreedBSD version checks for the original ctype UTF-8 workaround.

bpo-27473: Fixed possible integer overflow in bytes and bytearrayconcatenations. Patch by Xiang Zhang.

bpo-23034: The output of a special Python build with defined COUNT_ALLOCS,SHOW_ALLOC_COUNT or SHOW_TRACK_COUNT macros is now off by default. Itcan be re-enabled using the “-X showalloccount” option. It now outputs tostderr instead of stdout.

bpo-27443: __length_hint__() of bytearray iterators no longer return anegative integer for a resized bytearray.

bpo-27007: The fromhex() class methods of bytes and bytearray subclassesnow return an instance of corresponding subclass.

bpo-26844: Fix error message for imp.find_module() to refer to ‘path’instead of ‘name’. Patch by Lev Maximov.

bpo-23804: Fix SSL zero-length recv() calls to not block and not raise anerror about unclean EOF.

bpo-27466: Change time format returned by http.cookie.time2netscape,confirming the netscape cookie format and making it consistent withdocumentation.

bpo-21708: Deprecated dbm.dumb behavior that differs from common dbmbehavior: creating a database in ‘r’ and ‘w’ modes and modifying adatabase in ‘r’ mode.

bpo-26721: Change the socketserver.StreamRequestHandler.wfile attribute toimplement BufferedIOBase. In particular, the write() method no longer doespartial writes.

bpo-22115: Added methods trace_add, trace_remove and trace_info in thetkinter.Variable class. They replace old methods trace_variable, trace,trace_vdelete and trace_vinfo that use obsolete Tcl commands and might notwork in future versions of Tcl. Fixed old tracing methods:trace_vdelete() with wrong mode no longer break tracing, trace_vinfo() nowalways returns a list of pairs of strings, tracing in the “u” mode nowworks.

bpo-26243: Only the level argument to zlib.compress() is keyword argumentnow. The first argument is positional-only.

bpo-27038: Expose the DirEntry type as os.DirEntry. Code patch by JelleZijlstra.

bpo-27186: Update os.fspath()/PyOS_FSPath() to check the return value of__fspath__() to be either str or bytes.

bpo-18726: All optional parameters of the dump(), dumps(), load() andloads() functions and JSONEncoder and JSONDecoder class constructors inthe json module are now keyword-only.

bpo-27319: Methods selection_set(), selection_add(), selection_remove()and selection_toggle() of ttk.TreeView now allow passing multiple items asmultiple arguments instead of passing them as a tuple. Deprecatedundocumented ability of calling the selection() method with arguments.

bpo-27079: Fixed curses.ascii functions isblank(), iscntrl() andispunct().

bpo-27294: Numerical state in the repr for Tkinter event objects is nowrepresented as a combination of known flags.

bpo-27177: Match objects in the re module now support index-like objectsas group indices. Based on patches by Jeroen Demeyer and Xiang Zhang.

bpo-26754: Some functions (compile() etc) accepted a filename argumentencoded as an iterable of integers. Now only strings and byte-like objectsare accepted.

bpo-26536: socket.ioctl now supports SIO_LOOPBACK_FAST_PATH. Patch byDaniel Stokes.

bpo-27048: Prevents distutils failing on Windows when environmentvariables contain non-ASCII characters

bpo-27330: Fixed possible leaks in the ctypes module.

bpo-27238: Got rid of bare excepts in the turtle module. Original patchby Jelle Zijlstra.

bpo-27122: When an exception is raised within the context being managed bya contextlib.ExitStack() and one of the exit stack generators catches andraises it in a chain, do not re-raise the original exception when exiting,let the new chained one through. This avoids the PEP 479 bug described inissue25782.

bpo-27278: Fix os.urandom() implementation using getrandom() on Linux.Truncate size to INT_MAX and loop until we collected enough random bytes,instead of casting a directly Py_ssize_t to int.

bpo-16864: sqlite3.Cursor.lastrowid now supports REPLACE statement.Initial patch by Alex LordThorsen.

bpo-26386: Fixed ttk.TreeView selection operations with item id’scontaining spaces.

bpo-8637: Honor a pager set by the env var MANPAGER (in preference to oneset by the env var PAGER).

bpo-22636: Avoid shell injection problems with ctypes.util.find_library().

bpo-16182: Fix various functions in the “readline” module to use thelocale encoding, and fix get_begidx() and get_endidx() to return codepoint indexes.

bpo-27392: Add loop.connect_accepted_socket(). Patch by Jim Fulton.

bpo-27477: IDLE search dialogs now use ttk widgets.

bpo-27173: Add ‘IDLE Modern Unix’ to the built-in key sets. Make thedefault key set depend on the platform. Add tests for the changes to theconfig module.

bpo-27452: make command line “idle-test> python test_help.py” work.__file__ is relative when python is started in the file’s directory.

bpo-27452: add line counter and crc to IDLE configHandler test dump.

bpo-27380: IDLE: add query.py with base Query dialog and ttk widgets.Module had subclasses SectionName, ModuleName, and HelpSource, which areused to get information from users by configdialog and file =>Load Module.Each subclass has itw own validity checks. Using ModuleName allows usersto edit bad module names instead of starting over. Add tests and deletethe two files combined into the new one.

bpo-27372: Test_idle no longer changes the locale.

bpo-27365: Allow non-ascii chars in IDLE NEWS.txt, for contributor names.

bpo-27245: IDLE: Cleanly delete custom themes and key bindings.Previously, when IDLE was started from a console or by import, a cascadeof warnings was emitted. Patch by Serhiy Storchaka.

bpo-24137: Run IDLE, test_idle, and htest with tkinter default rootdisabled. Fix code and tests that fail with this restriction. Fix hteststo not create a second and redundant root and mainloop.

bpo-27310: Fix IDLE.app failure to launch on OS X due to vestigial import.

bpo-26754: PyUnicode_FSDecoder() accepted a filename argument encoded asan iterable of integers. Now only strings and byte-like objects areaccepted.

bpo-28066: Fix the logic that searches build directories for generatedinclude files when building outside the source tree.

bpo-27442: Expose the Android API level that python was built against, insysconfig.get_config_vars() as ‘ANDROID_API_LEVEL’.

bpo-27434: The interpreter that runs the cross-build, found in PATH, mustnow be of the same feature version (e.g. 3.6) as the source being built.

bpo-26930: Update Windows builds to use OpenSSL 1.0.2h.

bpo-23968: Rename the platform directory from plat-$(MACHDEP) toplat-$(PLATFORM_TRIPLET). Rename the config directory (LIBPL) fromconfig-$(LDVERSION) to config-$(LDVERSION)-$(PLATFORM_TRIPLET). Installthe platform specific _sysconfigdata module into the platform directoryand rename it to include the ABIFLAGS.

Don’t use largefile support for GNU/Hurd.

bpo-27332: Fixed the type of the first argument of module-level functionsgenerated by Argument Clinic. Patch by Petr Viktorin.

bpo-27418: Fixed Tools/importbench/importbench.py.

bpo-19489: Moved the search box from the sidebar to the header and footerof each page. Patch by Ammar Askar.

bpo-27285: Update documentation to reflect the deprecation ofpyvenvand normalize on the term “virtual environment”. Patch by Steve Piercy.

bpo-27027: Added test.support.is_android that is True when this is anAndroid build.

bpo-27095: Simplified MAKE_FUNCTION and removed MAKE_CLOSURE opcodes.Patch by Demur Rumed.

bpo-27190: Raise NotSupportedError if sqlite3 is older than 3.3.1. Patchby Dave Sawyer.

bpo-27286: Fixed compiling BUILD_MAP_UNPACK_WITH_CALL opcode. Callingfunction with generalized unpacking (PEP 448) and conflicting keywordnames could cause undefined behavior.

bpo-27140: Added BUILD_CONST_KEY_MAP opcode.

bpo-27186: Add support for os.PathLike objects to open() (part of PEP519).

bpo-27066: Fixed SystemError if a custom opener (for open()) returns anegative number without setting an exception.

bpo-26983: float() now always return an instance of exact float. Thedeprecation warning is emitted if __float__ returns an instance of astrict subclass of float. In a future versions of Python this can be anerror.

bpo-27097: Python interpreter is now about 7% faster due to optimizedinstruction decoding. Based on patch by Demur Rumed.

bpo-26647: Python interpreter now uses 16-bit wordcode instead ofbytecode. Patch by Demur Rumed.

bpo-23275: Allow assigning to an empty target list in round brackets: () =iterable.

bpo-27243: Update the __aiter__ protocol: instead of returning anawaitable that resolves to an asynchronous iterator, the asynchronousiterator should be returned directly. Doing the former will trigger aPendingDeprecationWarning.

Comment out socket (SO_REUSEPORT) and posix (O_SHLOCK, O_EXLOCK) constantsexposed on the API which are not implemented on GNU/Hurd. They would notwork at runtime anyway.

bpo-27025: Generated names for Tkinter widgets are now more meaningful andrecognizable.

bpo-25455: Fixed crashes in repr of recursive ElementTree.Element andfunctools.partial objects.

bpo-27294: Improved repr for Tkinter event objects.

bpo-20508: Improve exception message of IPv{4,6}Network.__getitem__. Patchby Gareth Rees.

bpo-26556: Update expat to 2.1.1, fixes CVE-2015-1283.

Fix TLS stripping vulnerability in smtplib, CVE-2016-0772. Reported byTeam Oststrom.

bpo-21386: Implement missing IPv4Address.is_global property. It wasdocumented since 07a5610bae9d. Initial patch by Roger Luethi.

bpo-27029: Removed deprecated support of universal newlines mode fromZipFile.open().

bpo-27030: Unknown escapes consisting of'\' and an ASCII letter inregular expressions now are errors. The re.LOCALE flag now can be usedonly with bytes patterns.

bpo-27186: Add os.PathLike support to DirEntry (part of PEP 519). Initialpatch by Jelle Zijlstra.

bpo-20900: distutils register command now decodes HTTP responsescorrectly. Initial patch by ingrid.

bpo-27186: Add os.PathLike support to pathlib, removing its provisionalstatus (part of PEP 519). Initial patch by Dusty Phillips.

bpo-27186: Add support for os.PathLike objects to os.fsencode() andos.fsdecode() (part of PEP 519).

bpo-27186: Introduce os.PathLike and os.fspath() (part of PEP 519).

A new version of typing.py provides several new classes and features:@overload outside stubs, Reversible, DefaultDict, Text, ContextManager,Type[], NewType(), TYPE_CHECKING, and numerous bug fixes (note that someof the new features are not yet implemented in mypy or other staticanalyzers). Also classes for PEP 492 (Awaitable, AsyncIterable,AsyncIterator) have been added (in fact they made it into 3.5.1 but werenever mentioned).

bpo-25738: Stop http.server.BaseHTTPRequestHandler.send_error() fromsending a message body for 205 Reset Content. Also, don’t send Contentheader fields in responses that don’t have a body. Patch by SusumuKoshiba.

bpo-21313: Fix the “platform” module to tolerate when sys.version containstruncated build information.

bpo-26839: On Linux,os.urandom() now callsgetrandom() withGRND_NONBLOCK to fall back on reading/dev/urandom if the urandomentropy pool is not initialized yet. Patch written by Colm Buckley.

bpo-23883: Added missing APIs to __all__ to match the documented APIs forthe following modules: cgi, mailbox, mimetypes, plistlib and smtpd.Patches by Jacek Kołodziej.

bpo-27164: In the zlib module, allow decompressing raw Deflate streamswith a predefined zdict. Based on patch by Xiang Zhang.

bpo-24291: Fix wsgiref.simple_server.WSGIRequestHandler to completelywrite data to the client. Previously it could do partial writes andtruncate data. Also, wsgiref.handler.ServerHandler can now handle stdoutdoing partial writes, but this is deprecated.

bpo-21272: Use _sysconfigdata.py to initialize distutils.sysconfig.

bpo-19611:inspect now reports the implicit.0 parametersgenerated by the compiler for comprehension and generator expressionscopes as if they were positional-only parameters calledimplicit0.Patch by Jelle Zijlstra.

bpo-26809: Add__all__ tostring. Patch by Emanuel Barry.

bpo-26373: subprocess.Popen.communicate now correctly ignoresBrokenPipeError when the child process dies before .communicate() iscalled in more/all circumstances.

signal, socket, and ssl module IntEnum constant name lookups now return aconsistent name for values having multiple names. Ex: signal.Signals(6)now refers to itself as signal.SIGALRM rather than flipping between thatand signal.SIGIOT based on the interpreter’s hash randomization seed.

bpo-27167: Clarify the subprocess.CalledProcessError error message textwhen the child process died due to a signal.

bpo-25931: Don’t define socketserver.Forking* names on platforms such asWindows that do not support os.fork().

bpo-21776: distutils.upload now correctly handles HTTPError. Initial patchby Claudiu Popa.

bpo-26526: Replace custom parse tree validation in the parser module witha simple DFA validator.

bpo-27114: Fix SSLContext._load_windows_store_certs fails withPermissionError

bpo-18383: Avoid creating duplicate filters when using filterwarnings andsimplefilter. Based on patch by Alex Shkop.

bpo-23026: winreg.QueryValueEx() now return an integer for REG_QWORD type.

bpo-26741: subprocess.Popen destructor now emits a ResourceWarning warningif the child process is still running.

bpo-27056: Optimize pickle.load() and pickle.loads(), up to 10% faster todeserialize a lot of small objects.

bpo-21271: New keyword only parameters in reset_mock call.

bpo-5124: Paste with text selected now replaces the selection on X11. Thismatches how paste works on Windows, Mac, most modern Linux apps, and ttkwidgets. Original patch by Serhiy Storchaka.

bpo-24750: Switch all scrollbars in IDLE to ttk versions. Where needed,minimal tests are added to cover changes.

bpo-24759: IDLE requires tk 8.5 and availability ttk widgets. Delete nowunneeded tk version tests and code for older versions. Add test for IDLEsyntax colorizer.

bpo-27239: idlelib.macosx.isXyzTk functions initialize as needed.

bpo-27262: move Aqua unbinding code, which enable context menus, tomacosx.

bpo-24759: Make clear in idlelib.idle_test.__init__ that the directory isa private implementation of test.test_idle and tool for maintainers.

bpo-27196: Stop ‘ThemeChanged’ warnings when running IDLE tests. Thesepersisted after other warnings were suppressed in #20567. Apply SerhiyStorchaka’s update_idletasks solution to four test files. Record thisadditional advice in idle_test/README.txt

bpo-20567: Revise idle_test/README.txt with advice about avoiding tkwarning messages from tests. Apply advice to several IDLE tests.

bpo-24225: Update idlelib/README.txt with new file names and eventhandlers.

bpo-27156: Remove obsolete code not used by IDLE.

bpo-27117: Make colorizer htest and turtledemo work with dark themes. Movecode for configuring text widget colors to a new function.

bpo-24225: Rename manyidlelib/*.py andidle_test/test_*.py files.Edit files to replace old names with new names when the old name referredto the module rather than the class it contained. See the issue and IDLEsection in What’s New in 3.6 for more.

bpo-26673: When tk reports font size as 0, change to size 10. Such fontson Linux prevented the configuration dialog from opening.

bpo-21939: Add test for IDLE’s percolator. Original patch by SaimadhavHeblikar.

bpo-21676: Add test for IDLE’s replace dialog. Original patch by SaimadhavHeblikar.

bpo-18410: Add test for IDLE’s search dialog. Original patch by WestleyMartínez.

bpo-21703: Add test for undo delegator. Patch mostly by SaimadhavHeblikar .

bpo-27044: Add ConfigDialog.remove_var_callbacks to stop memory leaks.

bpo-23977: Add more asserts to test_delegator.

bpo-16484: Change the default PYTHONDOCS URL to “https:”, and fix theresulting links to use lowercase. Patch by Sean Rodman, test by KaushikNadikuditi.

bpo-24136: Document the new PEP 448 unpacking syntax of 3.5.

bpo-22558: Add remaining doc links to source code for Python-codedmodules. Patch by Yoni Lavi.

bpo-25285: regrtest now uses subprocesses when the -j1 command line optionis used: each test file runs in a fresh child process. Before, the -j1option was ignored.

bpo-25285: Tools/buildbot/test.bat script now uses -j1 by default to runeach test file in fresh child process.

bpo-27064: The py.exe launcher now defaults to Python 3. The Windowslauncherpy.exe no longer prefers an installed Python 2 version overPython 3 by default when used interactively.

bpo-27229: Fix the cross-compiling pgen rule for in-tree builds. Patch byXavier de Gaye.

bpo-26930: Update OS X 10.5+ 32-bit-only installer to build and link withOpenSSL 1.0.2h.

bpo-17500: Remove unused and outdated icons. (See also:https://github.com/python/pythondotorg/issues/945)

bpo-27186: Add the PyOS_FSPath() function (part of PEP 519).

bpo-26282: PyArg_ParseTupleAndKeywords() now supports positional-onlyparameters.

bpo-26282: Argument Clinic now supports positional-only and keywordparameters in the same function.

bpo-20041: Fixed TypeError when frame.f_trace is set to None. Patch byXavier de Gaye.

bpo-26168: Fixed possible refleaks in failing Py_BuildValue() with the “N”format unit.

bpo-26991: Fix possible refleak when creating a function with annotations.

bpo-27039: Fixed bytearray.remove() for values greater than 127. Based onpatch by Joe Jevnik.

bpo-23640: int.from_bytes() no longer bypasses constructors forsubclasses.

bpo-27005: Optimized the float.fromhex() class method for exact float. Itis now 2 times faster.

bpo-18531: Single var-keyword argument of dict subtype was passedunscathed to the C-defined function. Now it is converted to exact dict.

bpo-26811: gc.get_objects() no longer contains a broken tuple with NULLpointer.

bpo-20120: Use RawConfigParser for .pypirc parsing, removing support forinterpolation unintentionally added with move to Python 3. Behavior nolonger does any interpolation in .pypirc files, matching behavior inPython 2.7 and Setuptools 19.0.

bpo-26249: Memory functions of thePyMem_Malloc() domain(PYMEM_DOMAIN_MEM) now use thepymalloc allocator rather than systemmalloc(). Applications callingPyMem_Malloc() without holding the GIL can now crash: usePYTHONMALLOC=debug environment variable to validate the usage ofmemory allocators in your application.

bpo-26802: Optimize function calls only using unpacking likefunc(*tuple) (no other positional argument, no keyword): avoid copyingthe tuple. Patch written by Joe Jevnik.

bpo-26659: Make the builtin slice type support cycle collection.

bpo-26718: super.__init__ no longer leaks memory if called multiple times.NOTE: A direct call of super.__init__ is not endorsed!

bpo-27138: Fix the doc comment for FileFinder.find_spec().

bpo-27147: Mention PEP 420 in the importlib docs.

bpo-25339: PYTHONIOENCODING now has priority over locale in setting theerror handler for stdin and stdout.

bpo-26494: Fixed crash on iterating exhausting iterators. Affected classesare generic sequence iterators, iterators of str, bytes, bytearray, list,tuple, set, frozenset, dict, OrderedDict, corresponding views andos.scandir() iterator.

bpo-26574: Optimizebytes.replace(b'',b'.') andbytearray.replace(b'',b'.'). Patch written by Josh Snider.

bpo-26581: If coding cookie is specified multiple times on a line inPython source code file, only the first one is taken to account.

bpo-19711: Add tests for reloading namespace packages.

bpo-21099: Switch applicable importlib tests to use PEP 451 API.

bpo-26563: Debug hooks on Python memory allocators now raise a fatal errorif functions of thePyMem_Malloc() family are called withoutholding the GIL.

bpo-26564: On error, the debug hooks on Python memory allocators now usethetracemalloc module to get the traceback where a memory blockwas allocated.

bpo-26558: The debug hooks on Python memory allocatorPyObject_Malloc() now detect when functions are called withoutholding the GIL.

bpo-26516: AddPYTHONMALLOC environment variable to set thePython memory allocators and/or install debug hooks.

bpo-26516: ThePyMem_SetupDebugHooks() function can now also beused on Python compiled in release mode.

bpo-26516: ThePYTHONMALLOCSTATS environment variable can nowalso be used on Python compiled in release mode. It now has no effect ifset to an empty string.

bpo-26516: In debug mode, debug hooks are now also installed on Pythonmemory allocators when Python is configured without pymalloc.

bpo-26464: Fix str.translate() when string is ASCII and first replacementsremoves character, but next replacement uses a non-ASCII character or astring longer than 1 character. Regression introduced in Python 3.5.0.

bpo-22836: Ensure exception reports from PyErr_Display() andPyErr_WriteUnraisable() are sensible even when formatting them producessecondary errors. This affects the reports produced bysys.__excepthook__() and when __del__() raises an exception.

bpo-26302: Correct behavior to reject comma as a legal character forcookie names.

bpo-26136: Upgrade the warning when a generator raises StopIteration fromPendingDeprecationWarning to DeprecationWarning. Patch by Anish Shah.

bpo-26204: The compiler now ignores all constant statements: bytes, str,int, float, complex, name constants (None, False, True), Ellipsis andast.Constant; not only str and int. For example,1.0 is now ignored indeff():1.0.

bpo-4806: Avoid masking the original TypeError exception when using star(*) unpacking in function calls. Based on patch by Hagen Fürstenauand Daniel Urban.

bpo-26146: Add a new kind of AST node:ast.Constant. It can be used byexternal AST optimizers, but the compiler does not emit directly suchnode.

bpo-23601: Sped-up allocation of dict key objects by using Python’s smallobject allocator. (Contributed by Julian Taylor.)

bpo-18018: Import raises ImportError instead of SystemError if a relativeimport is attempted without a known parent package.

bpo-25843: When compiling code, don’t merge constants if they are equalbut have a different types. For example,f1,f2=lambda:1,lambda:1.0 is now correctly compiled to two different functions:f1()returns1 (int) andf2() returns1.0 (float), even if1 and1.0 are equal.

bpo-26107: The format of theco_lnotab attribute of code objectschanges to support negative line number delta.

bpo-26154: Add a new private _PyThreadState_UncheckedGet() function to getthe current Python thread state, but don’t issue a fatal error if it isNULL. This new function must be used instead of accessing directly the_PyThreadState_Current variable. The variable is no more exposed sincePython 3.5.1 to hide the exact implementation of atomic C types, to avoidcompiler issues.

bpo-25791: If __package__ != __spec__.parent or if neither __package__ or__spec__ are defined then ImportWarning is raised.

bpo-22995: [UPDATE] Comment out the one of the pickleability tests in_PyObject_GetState() due to regressions observed in Cython-based projects.

bpo-25961: Disallowed null characters in the type name.

bpo-25973: Fix segfault when an invalid nonlocal statement binds a namestarting with two underscores.

bpo-22995: Instances of extension types with a state that aren’tsubclasses of list or dict and haven’t implemented any pickle-relatedmethods (__reduce__, __reduce_ex__, __getnewargs__, __getnewargs_ex__, or__getstate__), can no longer be pickled. Including memoryview.

bpo-20440: Massive replacing unsafe attribute setting code with specialmacro Py_SETREF.

bpo-25766: Special method __bytes__() now works in str subclasses.

bpo-25421: __sizeof__ methods of builtin types now use dynamic basic size.This allows sys.getsize() to work correctly with their subclasses with__slots__ defined.

bpo-25709: Fixed problem with in-place string concatenation and utf-8cache.

bpo-5319: New Py_FinalizeEx() API allowing Python to set an exit status of120 on failure to flush buffered streams.

bpo-25485: telnetlib.Telnet is now a context manager.

bpo-24097: Fixed crash in object.__reduce__() if slot name is freed inside__getattr__.

bpo-24731: Fixed crash on converting objects with special methods__bytes__, __trunc__, and __float__ returning instances of subclasses ofbytes, int, and float to subclasses of bytes, int, and floatcorrespondingly.

bpo-25630: Fix a possible segfault during argument parsing in functionsthat accept filesystem paths.

bpo-23564: Fixed a partially broken sanity check in the _posixsubprocessinternals regarding how fds_to_pass were passed to the child. The bug hadno actual impact as subprocess.py already avoided it.

bpo-25388: Fixed tokenizer crash when processing undecodable source codewith a null byte.

bpo-25462: The hash of the key now is calculated only once in mostoperations in C implementation of OrderedDict.

bpo-22995: Default implementation of __reduce__ and __reduce_ex__ nowrejects builtin types with not defined __new__.

bpo-24802: Avoid buffer overreads when int(), float(), compile(), exec()and eval() are passed bytes-like objects. These objects are notnecessarily terminated by a null byte, but the functions assumed theywere.

bpo-25555: Fix parser and AST: fill lineno and col_offset of “arg” nodewhen compiling AST from Python objects.

bpo-24726: Fixed a crash and leaking NULL in repr() of OrderedDict thatwas mutated by direct calls of dict methods.

bpo-25449: Iterating OrderedDict with keys with unstable hash now raisesKeyError in C implementations as well as in Python implementation.

bpo-25395: Fixed crash when highly nested OrderedDict structures weregarbage collected.

bpo-25401: Optimize bytes.fromhex() and bytearray.fromhex(): they are nowbetween 2x and 3.5x faster.

bpo-25399: Optimize bytearray % args using the new private _PyBytesWriterAPI. Formatting is now between 2.5 and 5 times faster.

bpo-25274: sys.setrecursionlimit() now raises a RecursionError if the newrecursion limit is too low depending at the current recursion depth.Modify also the “lower-water mark” formula to make it monotonic. This markis used to decide when the overflowed flag of the thread state is reset.

bpo-24402: Fix input() to prompt to the redirected stdout whensys.stdout.fileno() fails.

bpo-25349: Optimize bytes % args using the new private _PyBytesWriter API.Formatting is now up to 2 times faster.

bpo-24806: Prevent builtin types that are not allowed to be subclassedfrom being subclassed through multiple inheritance.

bpo-25301: The UTF-8 decoder is now up to 15 times as fast for errorhandlers:ignore,replace andsurrogateescape.

bpo-24848: Fixed a number of bugs in UTF-7 decoding of misformed data.

bpo-25267: The UTF-8 encoder is now up to 75 times as fast for errorhandlers:ignore,replace,surrogateescape,surrogatepass.Patch co-written with Serhiy Storchaka.

bpo-25280: Import trace messages emitted in verbose (-v) mode are nolonger formatted twice.

bpo-25227: Optimize ASCII and latin1 encoders with thesurrogateescapeerror handler: the encoders are now up to 3 times as fast. Initial patchwritten by Serhiy Storchaka.

bpo-25003: On Solaris 11.3 or newer, os.urandom() now uses the getrandom()function instead of the getentropy() function. The getentropy() functionis blocking to generate very good quality entropy, os.urandom() doesn’tneed such high-quality entropy.

bpo-9232: Modify Python’s grammar to allow trailing commas in the argumentlist of a function declaration. For example, “def f(*, a = 3,): pass” isnow legal. Patch from Mark Dickinson.

bpo-24965: Implement PEP 498 “Literal String Interpolation”. This allowsyou to embed expressions inside f-strings, which are converted to normalstrings at run time. Given x=3, then f’value={x}’ == ‘value=3’. Patch byEric V. Smith.

bpo-26478: Fix semantic bugs when using binary operators with dictionaryviews and tuples.

bpo-26171: Fix possible integer overflow and heap corruption inzipimporter.get_data().

bpo-25660: Fix TAB key behaviour in REPL with readline.

bpo-26288: Optimize PyLong_AsDouble.

bpo-26289: Optimize floor and modulo division for single-digit longs.Microbenchmarks show 2-2.5x improvement. Built-in ‘divmod’ function isnow also ~10% faster. (See also:bpo-26315)

bpo-25887: Raise a RuntimeError when a coroutine object is awaited morethan once.

bpo-27057: Fix os.set_inheritable() on Android, ioctl() is blocked bySELinux and fails with EACCESS. The function now falls back to fcntl().Patch written by Michał Bednarski.

bpo-27014: Fix infinite recursion using typing.py. Thanks to Kalle Tuure!

bpo-27031: Removed dummy methods in Tkinter widget classes: tk_menuBar()and tk_bindForTraversal().

bpo-14132: Fix urllib.request redirect handling when the target only has aquery string. Original fix by Ján Janech.

bpo-17214: The “urllib.request” module now percent-encodes non-ASCII bytesfound in redirect target URLs. Some servers send Location header fieldswith non-ASCII bytes, but “http.client” requires the request target to beASCII-encodable, otherwise a UnicodeEncodeError is raised. Based on patchby Christian Heimes.

bpo-27033: The default value of the decode_data parameter forsmtpd.SMTPChannel and smtpd.SMTPServer constructors is changed to False.

bpo-27034: Removed deprecated class asynchat.fifo.

bpo-26870: Added readline.set_auto_history(), which can stop entries beingautomatically added to the history list. Based on patch by TylerCrompton.

bpo-26039: zipfile.ZipFile.open() can now be used to write data into a ZIPfile, as well as for extracting data. Patch by Thomas Kluyver.

bpo-26892: Honor debuglevel flag in urllib.request.HTTPHandler. Patchcontributed by Chi Hsuan Yen.

bpo-22274: In the subprocess module, allow stderr to be redirected tostdout even when stdout is not redirected. Patch by Akira Li.

bpo-26807: mock_open ‘files’ no longer error on readline at end of file.Patch from Yolanda Robla.

bpo-25745: Fixed leaking a userptr in curses panel destructor.

bpo-26977: Removed unnecessary, and ignored, call to sum of squares helperin statistics.pvariance.

bpo-26002: Use bisect in statistics.median instead of a linear search.Patch by Upendra Kuma.

bpo-25974: Make use of new Decimal.as_integer_ratio() method in statisticsmodule. Patch by Stefan Krah.

bpo-26996: Add secrets module as described in PEP 506.

bpo-26881: The modulefinder module now supports extended opcode arguments.

bpo-23815: Fixed crashes related to directly created instances of types in_tkinter and curses.panel modules.

bpo-17765: weakref.ref() no longer silently ignores keyword arguments.Patch by Georg Brandl.

bpo-26873: xmlrpc now raises ResponseError on unsupported type tagsinstead of silently return incorrect result.

bpo-26915: The __contains__ methods in the collections ABCs now check foridentity before checking equality. This better matches the behavior ofthe concrete classes, allows sensible handling of NaNs, and makes iteasier to reason about container invariants.

bpo-26711: Fixed the comparison of plistlib.Data with other types.

bpo-24114: Fix an uninitialized variable inctypes.util.

The bug only occurs on SunOS when the ctypes implementation searches forthecrle program. Patch by Xiang Zhang. Tested on SunOS by Kees Bos.

bpo-26864: In urllib.request, change the proxy bypass host checkingagainst no_proxy to be case-insensitive, and to not match unrelated hostnames that happen to have a bypassed hostname as a suffix. Patch by XiangZhang.

bpo-24902: Print server URL on http.server startup. Initial patch byFelix Kaiser.

bpo-25788: fileinput.hook_encoded() now supports an “errors” argument forpassing to open. Original patch by Joseph Hackman.

bpo-26634: recursive_repr() now sets __qualname__ of wrapper. Patch byXiang Zhang.

bpo-26804: urllib.request will prefer lower_case proxy environmentvariables over UPPER_CASE or Mixed_Case ones. Patch contributed byHans-Peter Jansen.

bpo-26837: assertSequenceEqual() now correctly outputs non-stringifieddiffering items (like bytes in the -b mode). This affectsassertListEqual() and assertTupleEqual().

bpo-26041: Remove “will be removed in Python 3.7” from deprecationmessages of platform.dist() and platform.linux_distribution(). Patch byKumaripaba Miyurusara Athukorala.

bpo-26822: itemgetter, attrgetter and methodcaller objects no longersilently ignore keyword arguments.

bpo-26733: Disassembling a class now disassembles class and staticmethods. Patch by Xiang Zhang.

bpo-26801: Fix error handling inshutil.get_terminal_size(), catchAttributeError instead ofNameError. Patch written byEmanuel Barry.

bpo-24838: tarfile’s ustar and gnu formats now correctly calculate nameand link field limits for multibyte character encodings like utf-8.

bpo-26657: Fix directory traversal vulnerability with http.server onWindows. This fixes a regression that was introduced in 3.3.4rc1 and3.4.0rc1. Based on patch by Philipp Hagemeister.

bpo-26717: Stop encoding Latin-1-ized WSGI paths with UTF-8. Patch byAnthony Sottile.

bpo-26782: Add STARTUPINFO to subprocess.__all__ on Windows.

bpo-26404: Add context manager to socketserver. Patch by Aviv Palivoda.

bpo-26735: Fixos.urandom() on Solaris 11.3 and newer when readingmore than 1,024 bytes: callgetrandom() multiple times with a limit of1024 bytes per call.

bpo-26585: Eliminate http.server._quote_html() and usehtml.escape(quote=False). Patch by Xiang Zhang.

bpo-26685: Raise OSError if closing a socket fails.

bpo-16329: Add .webm to mimetypes.types_map. Patch by Giampaolo Rodola’.

bpo-13952: Add .csv to mimetypes.types_map. Patch by Geoff Wilson.

bpo-26587: the site module now allows .pth files to specify files to beadded to sys.path (e.g. zip files).

bpo-25609: Introduce contextlib.AbstractContextManager andtyping.ContextManager.

bpo-26709: Fixed Y2038 problem in loading binary PLists.

bpo-23735: Handle terminal resizing with Readline 6.3+ by installing ourown SIGWINCH handler. Patch by Eric Price.

bpo-25951: Change SSLSocket.sendall() to return None, as explicitlydocumented for plain socket objects. Patch by Aviv Palivoda.

bpo-26586: In http.server, respond with “413 Request header fields toolarge” if there are too many header fields to parse, rather than killingthe connection and raising an unhandled exception. Patch by Xiang Zhang.

bpo-26676: Added missing XMLPullParser to ElementTree.__all__.

bpo-22854: Change BufferedReader.writable() and BufferedWriter.readable()to always return False.

bpo-26492: Exhausted iterator of array.array now conforms with thebehavior of iterators of other mutable sequences: it lefts exhausted evenif iterated array is extended.

bpo-26641: doctest.DocFileTest and doctest.testfile() now support packages(module splitted into multiple directories) for the package parameter.

bpo-25195: Fix a regression in mock.MagicMock. _Call is a subclass oftuple (changeset 3603bae63c13 only works for classes) so we need toimplement __ne__ ourselves. Patch by Andrew Plummer.

bpo-26644: Raise ValueError rather than SystemError when a negative lengthis passed to SSLSocket.recv() or read().

bpo-23804: Fix SSL recv(0) and read(0) methods to return zero bytesinstead of up to 1024.

bpo-26616: Fixed a bug in datetime.astimezone() method.

bpo-26637: Theimportlib module now emits anImportErrorrather than aTypeError if__import__() is tried during thePython shutdown process butsys.path is already cleared (set toNone).

bpo-21925:warnings.formatwarning() now catches exceptions whencallinglinecache.getline() andtracemalloc.get_object_traceback() to be able to logResourceWarning emitted late during the Python shutdown process.

bpo-23848: On Windows, faulthandler.enable() now also installs anexception handler to dump the traceback of all Python threads on anyWindows exception, not only on UNIX signals (SIGSEGV, SIGFPE, SIGABRT).

bpo-26530: Add C functions_PyTraceMalloc_Track() and_PyTraceMalloc_Untrack() to track memory blocks using thetracemalloc module. Add_PyTraceMalloc_GetTraceback() toget the traceback of an object.

bpo-26588: The _tracemalloc now supports tracing memory allocations ofmultiple address spaces (domains).

bpo-24266: Ctrl+C during Readline history search now cancels the searchmode when compiled with Readline 7.

bpo-26590: Implement a safe finalizer for the _socket.socket type. It nowreleases the GIL to close the socket.

bpo-18787: spwd.getspnam() now raises a PermissionError if the userdoesn’t have privileges.

bpo-26560: Avoid potential ValueError in BaseHandler.start_response.Initial patch by Peter Inglesby.

bpo-26567: Add a new functionPyErr_ResourceWarning() function topass the destroyed object. Add asource attribute towarnings.WarningMessage. Add warnings._showwarnmsg() which usestracemalloc to get the traceback where source object was allocated.

bpo-26313: ssl.py _load_windows_store_certs fails if windows cert store isempty. Patch by Baji.

bpo-26569: Fixpyclbr.readmodule() andpyclbr.readmodule_ex()to support importing packages.

bpo-26499: Account for remaining Content-Length in HTTPResponse.readline()and read1(). Based on patch by Silent Ghost. Also document thatHTTPResponse now supports these methods.

bpo-25320: Handle sockets in directories unittest discovery is scanning.Patch from Victor van den Elzen.

bpo-16181: cookiejar.http2time() now returns None if year is higher thandatetime.MAXYEAR.

bpo-26513: Fixes platform module detection of Windows Server

bpo-23718: Fixed parsing time in week 0 before Jan 1. Original patch byTamás Bence Gedai.

bpo-26323: Add Mock.assert_called() and Mock.assert_called_once() methodsto unittest.mock. Patch written by Amit Saha.

bpo-20589: Invoking Path.owner() and Path.group() on Windows now raiseNotImplementedError instead of ImportError.

bpo-26177: Fixed the keys() method for Canvas and Scrollbar widgets.

bpo-15068: Got rid of excessive buffering in fileinput. The bufsizeparameter is now deprecated and ignored.

bpo-19475: Added an optional argument timespec to the datetime isoformat()method to choose the precision of the time component.

bpo-2202: Fix UnboundLocalError inAbstractDigestAuthHandler.get_algorithm_impls. Initial patch by MathieuDupuy.

bpo-26167: Minimized overhead in copy.copy() and copy.deepcopy().Optimized copying and deepcopying bytearrays, NotImplemented, slices,short lists, tuples, dicts, sets.

bpo-25718: Fixed pickling and copying the accumulate() iterator with totalis None.

bpo-26475: Fixed debugging output for regular expressions with the (?x)flag.

bpo-26482: Allowed pickling recursive dequeues.

bpo-26335: Make mmap.write() return the number of bytes written like otherwrite methods. Patch by Jakub Stasiak.

bpo-26457: Fixed the subnets() methods in IP network classes for the casewhen resulting prefix length is equal to maximal prefix length. Based onpatch by Xiang Zhang.

bpo-26385: Remove the file if the internal open() call inNamedTemporaryFile() fails. Patch by Silent Ghost.

bpo-26402: Fix XML-RPC client to retry when the server shuts down apersistent connection. This was a regression related to the newhttp.client.RemoteDisconnected exception in 3.5.0a4.

bpo-25913: Leading<~ is optional now in base64.a85decode() withadobe=True. Patch by Swati Jaiswal.

bpo-26186: Remove an invalid type check in importlib.util.LazyLoader.

bpo-26367: importlib.__import__() raises ImportError likebuiltins.__import__() whenlevel is specified but without anaccompanying package specified.

bpo-26309: In the “socketserver” module, shut down the request (closingthe connected socket) when verify_request() returns false. Patch by AvivPalivoda.

bpo-23430: Change the socketserver module to only catch exceptions raisedfrom a request handler that are derived from Exception (instead ofBaseException). Therefore SystemExit and KeyboardInterrupt no longertrigger the handle_error() method, and will now to stop a single-threadedserver.

bpo-25939: On Windows open the cert store readonly inssl.enum_certificates.

bpo-25995: os.walk() no longer uses FDs proportional to the tree depth.

bpo-25994: Added the close() method and the support of the context managerprotocol for the os.scandir() iterator.

bpo-23992: multiprocessing: make MapResult not fail-fast upon exception.

bpo-26243: Support keyword arguments to zlib.compress(). Patch by AvivPalivoda.

bpo-26117: The os.scandir() iterator now closes file descriptor not onlywhen the iteration is finished, but when it was failed with error.

bpo-25949: __dict__ for an OrderedDict instance is now created only whenneeded.

bpo-25911: Restored support of bytes paths in os.walk() on Windows.

bpo-26045: Add UTF-8 suggestion to error message when posting anon-Latin-1 string with http.client.

bpo-26039: Added zipfile.ZipInfo.from_file() and zipinfo.ZipInfo.is_dir().Patch by Thomas Kluyver.

bpo-12923: Reset FancyURLopener’s redirect counter even if there is anexception. Based on patches by Brian Brazil and Daniel Rocco.

bpo-25945: Fixed a crash when unpickle the functools.partial object withwrong state. Fixed a leak in failed functools.partial constructor. “args”and “keywords” attributes of functools.partial have now always types tupleand dict correspondingly.

bpo-26202: copy.deepcopy() now correctly copies range() objects withnon-atomic attributes.

bpo-23076: Path.glob() now raises a ValueError if it’s called with aninvalid pattern. Patch by Thomas Nyberg.

bpo-19883: Fixed possible integer overflows in zipimport.

bpo-26227: On Windows, getnameinfo(), gethostbyaddr() andgethostbyname_ex() functions of the socket module now decode the hostnamefrom the ANSI code page rather than UTF-8.

bpo-26099: The site module now writes an error into stderr ifsitecustomize module can be imported but executing the module raise anImportError. Same change for usercustomize.

bpo-26147: xmlrpc now works with strings not encodable with used non-UTF-8encoding.

bpo-25935: Garbage collector now breaks reference loops with OrderedDict.

bpo-16620: Fixed AttributeError in msilib.Directory.glob().

bpo-26013: Added compatibility with broken protocol 2 pickles created inold Python 3 versions (3.4.3 and lower).

bpo-26129: Deprecated accepting non-integers in grp.getgrgid().

bpo-25850: Use cross-compilation by default for 64-bit Windows.

bpo-25822: Add docstrings to the fields of urllib.parse results. Patchcontributed by Swati Jaiswal.

bpo-22642: Convert trace module option parsing mechanism to argparse.Patch contributed by SilentGhost.

bpo-24705: Fix sysconfig._parse_makefile not expanding ${} vars appearingbefore $() vars.

bpo-26069: Remove the deprecated apis in the trace module.

bpo-22138: Fix mock.patch behavior when patching descriptors. Restoreoriginal values after patching. Patch contributed by Sean McCully.

bpo-25672: In the ssl module, enable the SSL_MODE_RELEASE_BUFFERS modeoption if it is safe to do so.

bpo-26012: Don’t traverse into symlinks for** pattern inpathlib.Path.[r]glob().

bpo-24120: Ignore PermissionError when traversing a tree withpathlib.Path.[r]glob(). Patch by Ulrich Petri.

bpo-21815: Accept ] characters in the data portion of imap responses, inorder to handle the flags with square brackets accepted and produced byservers such as gmail.

bpo-25447: fileinput now uses sys.stdin as-is if it does not have a bufferattribute (restores backward compatibility).

bpo-25971: Optimized creating Fractions from floats by 2 times and fromDecimals by 3 times.

bpo-25802: Document as deprecated the remaining implementations ofimportlib.abc.Loader.load_module().

bpo-25928: Add Decimal.as_integer_ratio().

bpo-25447: Copying the lru_cache() wrapper object now always works,independently from the type of the wrapped object (by returning theoriginal object unchanged).

bpo-25768: Have the functions in compileall return booleans instead ofints and add proper documentation and tests for the return values.

bpo-24103: Fixed possible use after free in ElementTree.XMLPullParser.

bpo-25860: os.fwalk() no longer skips remaining directories when erroroccurs. Original patch by Samson Lee.

bpo-25914: Fixed and simplified OrderedDict.__sizeof__.

bpo-25869: Optimized deepcopying ElementTree; it is now 20 times faster.

bpo-25873: Optimized iterating ElementTree. Iterating elementsElement.iter() is now 40% faster, iterating text Element.itertext() is nowup to 2.5 times faster.

bpo-25902: Fixed various refcount issues in ElementTree iteration.

bpo-22227: The TarFile iterator is reimplemented using generator. Thisimplementation is simpler that using class.

bpo-25638: Optimized ElementTree.iterparse(); it is now 2x faster.Optimized ElementTree parsing; it is now 10% faster.

bpo-25761: Improved detecting errors in broken pickle data.

bpo-25717: Restore the previous behaviour of tolerating most fstat()errors when opening files. This was a regression in 3.5a1, and stoppedanonymous temporary files from working in special cases.

bpo-24903: Fix regression in number of arguments compileall accepts when‘-d’ is specified. The check on the number of arguments has been droppedcompletely as it never worked correctly anyway.

bpo-25764: In the subprocess module, preserve any exception caused byfork() failure when preexec_fn is used.

bpo-25771: Tweak the exception message for importlib.util.resolve_name()when ‘package’ isn’t specified but necessary.

bpo-6478: _strptime’s regexp cache now is reset after changing timezonewith time.tzset().

bpo-14285: When executing a package with the “python -m package” option,and package initialization fails, a proper traceback is now reported. The“runpy” module now lets exceptions from package initialization pass backto the caller, rather than raising ImportError.

bpo-19771: Also in runpy and the “-m” option, omit the irrelevant message“… is a package and cannot be directly executed” if the package couldnot even be initialized (e.g. due to a bad*.pyc file).

bpo-25177: Fixed problem with the mean of very small and very largenumbers. As a side effect, statistics.mean and statistics.variance shouldbe significantly faster.

bpo-25718: Fixed copying object with state with boolean value is false.

bpo-10131: Fixed deep copying of minidom documents. Based on patch byMarian Ganisin.

bpo-7990: dir() on ElementTree.Element now lists properties: “tag”,“text”, “tail” and “attrib”. Original patch by Santoso Wijaya.

bpo-25725: Fixed a reference leak in pickle.loads() when unpicklinginvalid data including tuple instructions.

bpo-25663: In the Readline completer, avoid listing duplicate globalnames, and search the global namespace before searching builtins.

bpo-25688: Fixed file leak in ElementTree.iterparse() raising an error.

bpo-23914: Fixed SystemError raised by unpickler on broken pickle data.

bpo-25691: Fixed crash on deleting ElementTree.Element attributes.

bpo-25624: ZipFile now always writes a ZIP_STORED header for directoryentries. Patch by Dingyuan Wang.

bpo-25626: Change three zlib functions to accept sizes that fit inPy_ssize_t, but internally cap those sizes to UINT_MAX. This resolves aregression in 3.5 where GzipFile.read() failed to read chunks larger than2 or 4 GiB. The change affects the zlib.Decompress.decompress()max_length parameter, the zlib.decompress() bufsize parameter, and thezlib.Decompress.flush() length parameter.

bpo-25583: Avoid incorrect errors raised by os.makedirs(exist_ok=True)when the OS gives priority to errors such as EACCES over EEXIST.

bpo-25593: Change semantics of EventLoop.stop() in asyncio.

bpo-6973: When we know a subprocess.Popen process has died, do not allowthe send_signal(), terminate(), or kill() methods to do anything as theycould potentially signal a different process.

bpo-23883: Added missing APIs to __all__ to match the documented APIs forthe following modules: calendar, csv, enum, fileinput, ftplib, logging,optparse, tarfile, threading and wave. Also added atest.support.check__all__() helper. Patches by Jacek Kołodziej, Mauro S.M. Rodrigues and Joel Taddei.

bpo-25590: In the Readline completer, only call getattr() once perattribute. Also complete names of attributes such as properties and slotswhich are listed by dir() but not yet created on an instance.

bpo-25498: Fix a crash when garbage-collecting ctypes objects created bywrapping a memoryview. This was a regression made in 3.5a1. Based onpatch by Eryksun.

bpo-25584: Added “escape” to the __all__ list in the glob module.

bpo-25584: Fixed recursive glob() with patterns starting with**.

bpo-25446: Fix regression in smtplib’s AUTH LOGIN support.

bpo-18010: Fix the pydoc web server’s module search function to handleexceptions from importing packages.

bpo-25554: Got rid of circular references in regular expression parsing.

bpo-18973: Command-line interface of the calendar module now uses argparseinstead of optparse.

bpo-25510: fileinput.FileInput.readline() now returns b’’ instead of ‘’ atthe end if the FileInput was opened with binary mode. Patch by RyosukeIto.

bpo-25503: Fixed inspect.getdoc() for inherited docstrings of properties.Original patch by John Mark Vandenberg.

bpo-25515: Always use os.urandom as a source of randomness in uuid.uuid4.

bpo-21827: Fixed textwrap.dedent() for the case when largest commonwhitespace is a substring of smallest leading whitespace. Based on patchby Robert Li.

bpo-25447: The lru_cache() wrapper objects now can be copied and pickled(by returning the original object unchanged).

bpo-25390: typing: Don’t crash on Union[str, Pattern].

bpo-25441: asyncio: Raise error from drain() when socket is closed.

bpo-25410: Cleaned up and fixed minor bugs in C implementation ofOrderedDict.

bpo-25411: Improved Unicode support in SMTPHandler through better use ofthe email package. Thanks to user simon04 for the patch.

Move the imp module from a PendingDeprecationWarning toDeprecationWarning.

bpo-25407: Remove mentions of the formatter module being removed in Python3.6.

bpo-25406: Fixed a bug in C implementation of OrderedDict.move_to_end()that caused segmentation fault or hang in iterating after moving severalitems to the start of ordered dict.

bpo-25382: pickletools.dis() now outputs implicit memo index for theMEMOIZE opcode.

bpo-25357: Add an optional newline parameter to binascii.b2a_base64().base64.b64encode() uses it to avoid a memory copy.

bpo-24164: Objects that need calling__new__ with keyword arguments,can now be pickled using pickle protocols older than protocol version 4.

bpo-25364: zipfile now works in threads disabled builds.

bpo-25328: smtpd’s SMTPChannel now correctly raises a ValueError if bothdecode_data and enable_SMTPUTF8 are set to true.

bpo-16099: RobotFileParser now supports Crawl-delay and Request-rateextensions. Patch by Nikolay Bogoychev.

bpo-25316: distutils raises OSError instead of DistutilsPlatformError whenMSVC is not installed.

bpo-25380: Fixed protocol for the STACK_GLOBAL opcode inpickletools.opcodes.

bpo-23972: Updates asyncio datagram create method allowing reuseport andreuseaddr socket options to be set prior to binding the socket. Mirroringthe existing asyncio create_server method the reuseaddr option fordatagram sockets defaults to True if the O/S is ‘posix’ (except if theplatform is Cygwin). Patch by Chris Laws.

bpo-25304: Add asyncio.run_coroutine_threadsafe(). This lets you submit acoroutine to a loop from another thread, returning aconcurrent.futures.Future. By Vincent Michel.

bpo-25232: Fix CGIRequestHandler to split the query from the URL at thefirst question mark (?) rather than the last. Patch from Xiang Zhang.

bpo-24657: Prevent CGIRequestHandler from collapsing slashes in the querypart of the URL as if it were a path. Patch from Xiang Zhang.

bpo-25287: Don’t add crypt.METHOD_CRYPT to crypt.methods if it’s notsupported. Check if it is supported, it may not be supported on OpenBSDfor example.

bpo-23600: Default implementation of tzinfo.fromutc() was returning wrongresults in some cases.

bpo-25203: Failed readline.set_completer_delims() no longer left themodule in inconsistent state.

bpo-25011: rlcompleter now omits private and special attribute namesunless the prefix starts with underscores.

bpo-25209: rlcompleter now can add a space or a colon after completedkeyword.

bpo-22241: timezone.utc name is now plain ‘UTC’, not ‘UTC-00:00’.

bpo-23517: fromtimestamp() and utcfromtimestamp() methods ofdatetime.datetime now round microseconds to nearest with ties going tonearest even integer (ROUND_HALF_EVEN), as round(float), instead ofrounding towards -Infinity (ROUND_FLOOR).

bpo-23552: Timeit now warns when there is substantial (4x) variancebetween best and worst times. Patch from Serhiy Storchaka.

bpo-24633: site-packages/README -> README.txt.

bpo-24879: help() and pydoc can now list named tuple fields in the orderthey were defined rather than alphabetically. The ordering is determinedby the _fields attribute if present.

bpo-24874: Improve speed of itertools.cycle() and make its pickle morecompact.

Fix crash in itertools.cycle.__setstate__() when the first argument wasn’ta list.

bpo-20059: urllib.parse raises ValueError on all invalid ports. Patch byMartin Panter.

bpo-24360: Improve __repr__ of argparse.Namespace() for invalididentifiers. Patch by Matthias Bussonnier.

bpo-23426: run_setup was broken in distutils. Patch from AlexanderBelopolsky.

bpo-13938: 2to3 converts StringTypes to a tuple. Patch from Mark Hammond.

bpo-2091: open() accepted a ‘U’ mode string containing ‘+’, but ‘U’ canonly be used with ‘r’. Patch from Jeff Balogh and John O’Connor.

bpo-8585: improved tests for zipimporter2. Patch from Mark Lawrence.

bpo-18622: unittest.mock.mock_open().reset_mock would recurse infinitely.Patch from Nicola Palumbo and Laurent De Buyst.

bpo-24426: Fast searching optimization in regular expressions now worksfor patterns that starts with capturing groups. Fast searchingoptimization now can’t be disabled at compile time.

bpo-23661: unittest.mock side_effects can now be exceptions again. Thiswas a regression vs Python 3.4. Patch from Ignacio Rossi

bpo-13248: Remove deprecated inspect.getmoduleinfo function.

bpo-25578: Fix (another) memory leak in SSLSocket.getpeercer().

bpo-25530: Disable the vulnerable SSLv3 protocol by default when creatingssl.SSLContext.

bpo-25569: Fix memory leak in SSLSocket.getpeercert().

bpo-25471: Sockets returned from accept() shouldn’t appear to benonblocking.

bpo-25319: When threading.Event is reinitialized, the underlying conditionshould use a regular lock rather than a recursive lock.

Skip getaddrinfo if host is already resolved. Patch by A. Jesse JiryuDavis.

bpo-26050: Add asyncio.StreamReader.readuntil() method. Patch by МаркКоренберг.

bpo-25924: Avoid unnecessary serialization of getaddrinfo(3) calls on OS Xversions 10.5 or higher. Original patch by A. Jesse Jiryu Davis.

bpo-26406: Avoid unnecessary serialization of getaddrinfo(3) calls oncurrent versions of OpenBSD and NetBSD. Patch by A. Jesse Jiryu Davis.

bpo-26848: Fix asyncio/subprocess.communicate() to handle empty input.Patch by Jack O’Connor.

bpo-27040: Add loop.get_exception_handler method

bpo-27041: asyncio: Add loop.create_future method

bpo-20640: Add tests for idlelib.configHelpSourceEdit. Patch by SaimadhavHeblikar.

In the ‘IDLE-console differences’ section of the IDLE doc, clarify howrunning with IDLE affects sys.modules and the standard streams.

bpo-25507: fix incorrect change in IOBinding that prevented printing.Augment IOBinding htest to include all major IOBinding functions.

bpo-25905: Revert unwanted conversion of ‘ to ’ RIGHT SINGLE QUOTATIONMARK in README.txt and open this and NEWS.txt with ‘ascii’. Re-encodeCREDITS.txt to utf-8 and open it with ‘utf-8’.

bpo-15348: Stop the debugger engine (normally in a user process) beforeclosing the debugger window (running in the IDLE process). This preventsthe RuntimeErrors that were being caught and ignored.

bpo-24455: Prevent IDLE from hanging when a) closing the shell while thedebugger is active (15347); b) closing the debugger with the [X] button(15348); and c) activating the debugger when already active (24455). Thepatch by Mark Roseman does this by making two changes. 1. Suspend andresume the gui.interaction method with the tcl vwait mechanism intendedfor this purpose (instead of root.mainloop & .quit). 2. In gui.run, allowany existing interaction to terminate first.

Change ‘The program’ to ‘Your program’ in an IDLE ‘kill program?’ messageto make it clearer that the program referred to is the currently runninguser program, not IDLE itself.

bpo-24750: Improve the appearance of the IDLE editor window status bar.Patch by Mark Roseman.

bpo-25313: Change the handling of new built-in text color themes to betteraddress the compatibility problem introduced by the addition of IDLE Dark.Consistently use the revised idleConf.CurrentTheme everywhere in idlelib.

bpo-24782: Extension configuration is now a tab in the IDLE Preferencesdialog rather than a separate dialog. The former tabs are now a sortedlist. Patch by Mark Roseman.

bpo-22726: Re-activate the config dialog help button with some contentabout the other buttons and the new IDLE Dark theme.

bpo-24820: IDLE now has an ‘IDLE Dark’ built-in text color theme. It ismore or less IDLE Classic inverted, with a cobalt blue background.Strings, comments, keywords, … are still green, red, orange, … . Touse it with IDLEs released before November 2015, hit the ‘Save as NewCustom Theme’ button and enter a new name, such as ‘Custom Dark’. Thecustom theme will work with any IDLE release, and can be modified.

bpo-25224: README.txt is now an idlelib index for IDLE developers andcurious users. The previous user content is now in the IDLE doc chapter.‘IDLE’ now means ‘Integrated Development and Learning Environment’.

bpo-24820: Users can now set breakpoint colors in Settings -> CustomHighlighting. Original patch by Mark Roseman.

bpo-24972: Inactive selection background now matches active selectionbackground, as configured by users, on all systems. Found items are nowalways highlighted on Windows. Initial patch by Mark Roseman.

bpo-24570: Idle: make calltip and completion boxes appear on Macs affectedby a tk regression. Initial patch by Mark Roseman.

bpo-24988: Idle ScrolledList context menus (used in debugger) now work onMac Aqua. Patch by Mark Roseman.

bpo-24801: Make right-click for context menu work on Mac Aqua. Patch byMark Roseman.

bpo-25173: Associate tkinter messageboxes with a specific widget. For MacOSX, make them a ‘sheet’. Patch by Mark Roseman.

bpo-25198: Enhance the initial html viewer now used for Idle Help.Properly indent fixed-pitch text (patch by Mark Roseman). Give codesnippet a very Sphinx-like light blueish-gray background. Re-use initialwidth and height set by users for shell and editor. When the Table ofContents (TOC) menu is used, put the section header at the top of thescreen.

bpo-25225: Condense and rewrite Idle doc section on text colors.

bpo-21995: Explain some differences between IDLE and console Python.

bpo-22820: Explain need forprint when running file from Idle editor.

bpo-25224: Doc: augment Idle feature list and no-subprocess section.

bpo-25219: Update doc for Idle command line options. Some were missing andnotes were not correct.

bpo-24861: Most of idlelib is private and subject to change. Useidleib.idle.* to start Idle. See idlelib.__init__.__doc__.

bpo-25199: Idle: add synchronization comments for future maintainers.

bpo-16893: Replace help.txt with help.html for Idle doc display. The newidlelib/help.html is rstripped Doc/build/html/library/idle.html. It looksbetter than help.txt and will better document Idle as released. Thetkinter html viewer that works for this file was written by Rose Roseman.The now unused EditorWindow.HelpDialog class and helt.txt file aredeprecated.

bpo-24199: Deprecate unused idlelib.idlever with possible removal in 3.6.

bpo-24790: Remove extraneous code (which also create 2 & 3 conflicts).

bpo-26736: Used HTTPS for external links in the documentation if possible.

bpo-6953: Rework the Readline module documentation to group relatedfunctions together, and add more details such as what underlying Readlinefunctions and variables are accessed.

bpo-23606: Adds note to ctypes documentation regarding cdll.msvcrt.

bpo-24952: Clarify the default size argument of stack_size() in the“threading” and “_thread” modules. Patch from Mattip.

bpo-26014: Update 3.x packaging documentation: * “See also” links to thenew docs are now provided in the legacy pages * links to setuptoolsdocumentation have been updated

bpo-21916: Added tests for the turtle module. Patch by ingrid, GregoryLoyse and Jelle Zijlstra.

bpo-26295: When using “python3 -m test –testdir=TESTDIR”, regrtestdoesn’t add “test.” prefix to test module names.

bpo-26523: The multiprocessing thread pool (multiprocessing.dummy.Pool)was untested.

bpo-26015: Added new tests for pickling iterators of mutable sequences.

bpo-26325: Added test.support.check_no_resource_warning() to check that noResourceWarning is emitted.

bpo-25940: Changed test_ssl to use its internal local server more. Thisavoids relying on svn.python.org, which recently changed root certificate.

bpo-25616: Tests for OrderedDict are extracted from test_collections intoseparate file test_ordered_dict.

bpo-25449: Added tests for OrderedDict subclasses.

bpo-25188: Add -P/–pgo to test.regrtest to suppress error output whenrunning the test suite for the purposes of a PGO build. Initial patch byAlecsandru Patrascu.

bpo-22806: Addpython-mtest--list-tests command to list tests.

bpo-18174:python-mtest--huntrleaks... now also checks for leak offile descriptors. Patch written by Richard Oudkerk.

bpo-25260: Fixpython-mtest--coverage on Windows. Remove the listof ignored directories.

PCbuild\rt.bat now accepts an unlimited number of arguments to passalong to regrtest.py. Previously there was a limit of 9.

bpo-26583: Skip test_timestamp_overflow in test_import if bytecode filescannot be written.

bpo-21277: Don’t try to link _ctypes with a ffi_convenience library.

bpo-26884: Fix linking extension modules for cross builds. Patch by Xavierde Gaye.

bpo-26932: Fixed support of RTLD_* constants defined as enum values, notvia macros (in particular on Android). Patch by Chi Hsuan Yen.

bpo-22359: Disable the rules for running _freeze_importlib and pgen whencross-compiling. The output of these programs is normally saved with thesource code anyway, and is still regenerated when doing a native build.Patch by Xavier de Gaye.

bpo-21668: Link audioop, _datetime, _ctypes_test modules to libm, excepton Mac OS X. Patch written by Chi Hsuan Yen.

bpo-25702: A –with-lto configure option has been added that will enablelink time optimizations at build time during a make profile-opt. Somecompilers and toolchains are known to not produce stable code when usingLTO, be sure to test things thoroughly before relying on it. It canprovide a few % speed up over profile-opt alone.

bpo-26624: Adds validation of ucrtbase[d].dll version with warning for oldversions.

bpo-17603: Avoid error about nonexistant fileblocks.o file by using alower-level check for st_blocks in struct stat.

bpo-26079: Fixing the build output folder for tix-8.4.3.6. Patch by BjoernThiel.

bpo-26465: Update Windows builds to use OpenSSL 1.0.2g.

bpo-25348: Added--pgo and--pgo-job arguments toPCbuild\build.bat for building with Profile-Guided Optimization. TheoldPCbuild\build_pgo.bat script is removed.

bpo-25827: Add support for building with ICC toconfigure, including anew--with-icc flag.

bpo-25696: Fix installation of Python on UNIX with make -j9.

bpo-24986: It is now possible to build Python on Windows without errorswhen external libraries are not available.

bpo-24421: Compile Modules/_math.c once, before building extensions.Previously it could fail to compile properly if the math and cmath buildswere concurrent.

bpo-26465: Update OS X 10.5+ 32-bit-only installer to build and link withOpenSSL 1.0.2g.

bpo-26268: Update Windows builds to use OpenSSL 1.0.2f.

bpo-25136: Support Apple Xcode 7’s new textual SDK stub libraries.

bpo-24324: Do not enable unreachable code warnings when using gcc as theoption does not work correctly in older versions of gcc and has beensilently removed as of gcc-4.5.

bpo-27053: Updates make_zip.py to correctly generate library ZIP file.

bpo-26268: Update the prepare_ssl.py script to handle OpenSSL releasesthat don’t include the contents of the include directory (that is, 1.0.2eand later).

bpo-26071: bdist_wininst created binaries fail to start and find 32bitPython

bpo-26073: Update the list of magic numbers in launcher

bpo-26065: Excludes venv from library when generating embeddable distro.

bpo-25022: Removed very outdated PC/example_nt/ directory.

bpo-26799: Fix python-gdb.py: don’t get C types once when the Python codeis loaded, but get C types on demand. The C types can change ifpython-gdb.py is loaded before the Python executable. Patch written byThomas Ilsche.

bpo-26271: Fix the Freeze tool to properly use flags passed throughconfigure. Patch by Daniel Shaulov.

bpo-26489: Add dictionary unpacking support to Tools/parser/unparse.py.Patch by Guo Ci Teo.

bpo-26316: Fix variable name typo in Argument Clinic.

bpo-25440: Fix output of python-config –extension-suffix.

bpo-25154: The pyvenv script has been deprecated in favour ofpython3-mvenv.