3.7.0a2 - Cpython — ContextQMD

.. bpo: 31558 .. date: 2017-10-16-14-27-25 .. nonce: K-uRRm .. release date: 2017-10-16 .. section: Core and Builtins

gc.freeze() is a new API that allows for moving all objects currently tracked by the garbage collector to a permanent generation, effectively removing them from future collection events. This can be used to protect those objects from having their PyGC_Head mutated. In effect, this enables great copy-on-write stability at fork().

.. bpo: 31642 .. date: 2017-10-08-10-00-55 .. nonce: 1IKqgs .. section: Core and Builtins

Restored blocking "from package import module" by setting sys.modules["package.module"] to None.

.. bpo: 31708 .. date: 2017-10-06-02-10-48 .. nonce: 66CCVU .. section: Core and Builtins

Allow use of asynchronous generator expressions in synchronous functions.

.. bpo: 31709 .. date: 2017-10-06-00-27-04 .. nonce: _PmU51 .. section: Core and Builtins

Drop support of asynchronous aiter.

.. bpo: 30404 .. date: 2017-10-03-23-46-39 .. nonce: _9Yi5u .. section: Core and Builtins

The -u option now makes the stdout and stderr streams unbuffered rather than line-buffered.

.. bpo: 31619 .. date: 2017-09-29-20-32-24 .. nonce: 6gQ1kv .. section: Core and Builtins

Fixed a ValueError when convert a string with large number of underscores to integer with binary base.

.. bpo: 31602 .. date: 2017-09-27-09-30-03 .. nonce: MtgLCn .. section: Core and Builtins

Fix an assertion failure in zipimporter.get_source() in case of a bad zlib.decompress(). Patch by Oren Milman.

.. bpo: 31592 .. date: 2017-09-26-16-05-04 .. nonce: IFBZj9 .. section: Core and Builtins

Fixed an assertion failure in Python parser in case of a bad unicodedata.normalize(). Patch by Oren Milman.

.. bpo: 31588 .. date: 2017-09-26-13-03-16 .. nonce: wT9Iy7 .. section: Core and Builtins

Raise a TypeError with a helpful error message when class creation fails due to a metaclass with a bad __prepare__() method. Patch by Oren Milman.

.. bpo: 31574 .. date: 2017-09-25-12-35-48 .. nonce: 5yX5r5 .. section: Core and Builtins

Importlib was instrumented with two dtrace probes to profile import timing.

.. bpo: 31566 .. date: 2017-09-24-09-57-04 .. nonce: OxwINs .. section: Core and Builtins

Fix an assertion failure in _warnings.warn() in case of a bad __name__ global. Patch by Oren Milman.

.. bpo: 31506 .. date: 2017-09-19-10-29-36 .. nonce: pRVTRB .. section: Core and Builtins

Improved the error message logic for object.__new__ and object.__init__.

.. bpo: 31505 .. date: 2017-09-18-12-07-39 .. nonce: VomaFa .. section: Core and Builtins

Fix an assertion failure in json, in case _json.make_encoder() received a bad encoder() argument. Patch by Oren Milman.

.. bpo: 31492 .. date: 2017-09-16-22-49-16 .. nonce: RtyteL .. section: Core and Builtins

Fix assertion failures in case of failing to import from a module with a bad __name__ attribute, and in case of failing to access an attribute of such a module. Patch by Oren Milman.

.. bpo: 31478 .. date: 2017-09-15-09-13-07 .. nonce: o06iKD .. section: Core and Builtins

Fix an assertion failure in _random.Random.seed() in case the argument has a bad __abs__() method. Patch by Oren Milman.

.. bpo: 31336 .. date: 2017-09-13-12-04-23 .. nonce: gi2ahY .. section: Core and Builtins

Speed up class creation by 10-20% by reducing the overhead in the necessary special method lookups. Patch by Stefan Behnel.

.. bpo: 31415 .. date: 2017-09-11-14-28-56 .. nonce: GBdz7o .. section: Core and Builtins

Add -X importtime option to show how long each import takes. It can be used to optimize application's startup time. Support the :envvar:PYTHONPROFILEIMPORTTIME as an equivalent way to enable this.

.. bpo: 31410 .. date: 2017-09-10-20-58-51 .. nonce: wD_RbH .. section: Core and Builtins

Optimized calling wrapper and classmethod descriptors.

.. bpo: 31353 .. date: 2017-09-05-14-19-02 .. nonce: oGZUeJ .. section: Core and Builtins

:pep:553 - Add a new built-in called breakpoint() which calls sys.breakpointhook(). By default this imports pdb and calls pdb.set_trace(), but users may override sys.breakpointhook() to call whatever debugger they want. The original value of the hook is saved in sys.__breakpointhook__.

.. bpo: 17852 .. date: 2017-09-04-12-46-25 .. nonce: OxAtCg .. section: Core and Builtins

Maintain a list of open buffered files, flush them before exiting the interpreter. Based on a patch from Armin Rigo.

.. bpo: 31315 .. date: 2017-09-01-00-40-58 .. nonce: ZX20bl .. section: Core and Builtins

Fix an assertion failure in imp.create_dynamic(), when spec.name is not a string. Patch by Oren Milman.

.. bpo: 31311 .. date: 2017-08-31-17-52-56 .. nonce: bNE2l- .. section: Core and Builtins

Fix a crash in the __setstate__() method of ctypes._CData, in case of a bad __dict__. Patch by Oren Milman.

.. bpo: 31293 .. date: 2017-08-28-17-51-42 .. nonce: eMYZXj .. section: Core and Builtins

Fix crashes in true division and multiplication of a timedelta object by a float with a bad as_integer_ratio() method. Patch by Oren Milman.

.. bpo: 31285 .. date: 2017-08-27-21-18-30 .. nonce: 7lzaKV .. section: Core and Builtins

Fix an assertion failure in warnings.warn_explicit, when the return value of the received loader's get_source() has a bad splitlines() method. Patch by Oren Milman.

.. bpo: 30406 .. date: 2017-07-20-22-03-44 .. nonce: _kr47t .. section: Core and Builtins

Make async and await proper keywords, as specified in :pep:492.

.. bpo: 30058 .. date: 2017-10-12-19-00-53 .. nonce: cENtry .. section: Library

Fixed buffer overflow in select.kqueue.control().

.. bpo: 31672 .. date: 2017-10-12-02-47-16 .. nonce: DaOkVd .. section: Library

idpattern in string.Template matched some non-ASCII characters. Now it uses -i regular expression local flag to avoid non-ASCII characters.

.. bpo: 31701 .. date: 2017-10-09-17-42-30 .. nonce: NRrVel .. section: Library

On Windows, faulthandler.enable() now ignores MSC and COM exceptions.

.. bpo: 31728 .. date: 2017-10-08-23-28-30 .. nonce: XrVMME .. section: Library

Prevent crashes in _elementtree due to unsafe cleanup of Element.text and Element.tail. Patch by Oren Milman.

.. bpo: 31671 .. date: 2017-10-04-21-28-44 .. nonce: E-zfc9 .. section: Library

Now re.compile() converts passed RegexFlag to normal int object before compiling. bm_regex_compile benchmark shows 14% performance improvements.

.. bpo: 30397 .. date: 2017-10-03-22-45-50 .. nonce: e4F7Kr .. section: Library

The types of compiled regular objects and match objects are now exposed as re.Pattern and re.Match. This adds information in pydoc output for the re module.

.. bpo: 31675 .. date: 2017-10-03-15-06-24 .. nonce: Nh7jJ3 .. section: Library

Fixed memory leaks in Tkinter's methods splitlist() and split() when pass a string larger than 2 GiB.

.. bpo: 31673 .. date: 2017-10-03-14-37-46 .. nonce: RFCrka .. section: Library

Fixed typo in the name of Tkinter's method adderrorinfo().

.. bpo: 31648 .. date: 2017-09-30-10-45-12 .. nonce: Cai7ji .. section: Library

Improvements to path predicates in ElementTree: Allow whitespace around predicate parts, i.e. "[a = 'text']" instead of requiring the less readable "[a='text']". Add support for text comparison of the current node, like "[.='text']". Patch by Stefan Behnel.

.. bpo: 30806 .. date: 2017-09-29 .. nonce: lP5GrH .. section: Library

Fix the string representation of a netrc object.

.. bpo: 31638 .. date: 2017-09-29-07-14-28 .. nonce: jElfhl .. section: Library

Add optional argument compressed to zipapp.create_archive, and add option --compress to the command line interface of zipapp.

.. bpo: 25351 .. date: 2017-09-28-23-10-51 .. nonce: 2JmFpF .. section: Library

Avoid venv activate failures with undefined variables

.. bpo: 20519 .. date: 2017-09-28-13-17-33 .. nonce: FteeQQ .. section: Library

Avoid ctypes use (if possible) and improve import time for uuid.

.. bpo: 28293 .. date: 2017-09-26-17-51-17 .. nonce: UC5pm4 .. section: Library

The regular expression cache is no longer completely dumped when it is full.

.. bpo: 31596 .. date: 2017-09-26-11-38-52 .. nonce: 50Eyel .. section: Library

Added pthread_getcpuclockid() to the time module

.. bpo: 27494 .. date: 2017-09-26-01-43-17 .. nonce: 37QnaT .. section: Library

Make 2to3 accept a trailing comma in generator expressions. For example, set(x for x in [],) is now allowed.

.. bpo: 30347 .. date: 2017-09-25-14-04-30 .. nonce: B4--_D .. section: Library

Stop crashes when concurrently iterate over itertools.groupby() iterators.

.. bpo: 30346 .. date: 2017-09-24-13-08-46 .. nonce: Csse77 .. section: Library

An iterator produced by itertools.groupby() iterator now becomes exhausted after advancing the groupby iterator.

.. bpo: 31556 .. date: 2017-09-22-23-48-49 .. nonce: 9J0u5H .. section: Library

Cancel asyncio.wait_for future faster if timeout <= 0

.. bpo: 31540 .. date: 2017-09-22-16-02-00 .. nonce: ybDHT5 .. section: Library

Allow passing a context object in :class:concurrent.futures.ProcessPoolExecutor constructor. Also, free job resources in :class:concurrent.futures.ProcessPoolExecutor earlier to improve memory usage when a worker waits for new jobs.

.. bpo: 31516 .. date: 2017-09-20-18-43-01 .. nonce: 23Yuq3 .. section: Library

threading.current_thread() should not return a dummy thread at shutdown.

.. bpo: 31525 .. date: 2017-09-19-18-48-21 .. nonce: O2TIL2 .. section: Library

In the sqlite module, require the sqlite3_prepare_v2 API. Thus, the sqlite module now requires sqlite version at least 3.3.9.

.. bpo: 26510 .. date: 2017-09-19-13-29-29 .. nonce: oncW6V .. section: Library

argparse subparsers are now required by default. This matches behaviour in Python 2. For optional subparsers, use the new parameter add_subparsers(required=False). Patch by Anthony Sottile. (As of 3.7.0rc1, the default was changed to not required as had been the case since Python 3.3.)

.. bpo: 27541 .. date: 2017-09-17-19-59-04 .. nonce: cIMFJW .. section: Library

Reprs of subclasses of some collection and iterator classes (bytearray, array.array, collections.deque, collections.defaultdict, itertools.count, itertools.repeat) now contain actual type name instead of hardcoded names of the base class.

.. bpo: 31351 .. date: 2017-09-17-15-24-25 .. nonce: yQdKv- .. section: Library

python -m ensurepip now exits with non-zero exit code if pip bootstrapping has failed.

.. bpo: 31389 .. date: 2017-09-07-15-31-47 .. nonce: jNFYqB .. section: Library

pdb.set_trace() now takes an optional keyword-only argument header. If given, this is printed to the console just before debugging begins.

.. bpo: 31537 .. date: 2017-10-08-23-02-14 .. nonce: SiFNM8 .. section: Documentation

Fix incorrect usage of get_history_length in readline documentation example code. Patch by Brad Smith.

.. bpo: 30085 .. date: 2017-09-14-18-44-50 .. nonce: 0J9w-u .. section: Documentation

The operator functions without double underscores are preferred for clarity. The one with underscores are only kept for back-compatibility.

.. bpo: 31696 .. date: 2017-10-04-23-40-32 .. nonce: Y3_aBV .. section: Build

Improve compiler version information in :data:sys.version when Python is built with Clang.

.. bpo: 31625 .. date: 2017-09-28-23-21-20 .. nonce: Bb2NXr .. section: Build

Stop using ranlib on static libraries. Instead, we assume ar supports the 's' flag.

.. bpo: 31624 .. date: 2017-09-28-20-54-52 .. nonce: 11w91_ .. section: Build

Remove support for BSD/OS.

.. bpo: 22140 .. date: 2017-09-26-22-39-58 .. nonce: ZRf7Wn .. section: Build

Prevent double substitution of prefix in python-config.sh.

.. bpo: 31569 .. date: 2017-09-25-00-25-23 .. nonce: TS49pM .. section: Build

Correct PCBuild/ case to PCbuild/ in build scripts and documentation.

.. bpo: 31536 .. date: 2017-09-20-21-32-21 .. nonce: KUDjno .. section: Build

Avoid wholesale rebuild after make regen-all if nothing changed.

.. bpo: 31460 .. date: 2017-09-30-19-03-26 .. nonce: HpveI6 .. section: IDLE

Simplify the API of IDLE's Module Browser. Passing a widget instead of an flist with a root widget opens the option of creating a browser frame that is only part of a window. Passing a full file name instead of pieces assumed to come from a .py file opens the possibility of browsing python files that do not end in .py.

.. bpo: 31649 .. date: 2017-09-30-13-59-18 .. nonce: LxN4Vb .. section: IDLE

IDLE - Make _htest, _utest parameters keyword only.

.. bpo: 31559 .. date: 2017-09-23-12-52-24 .. nonce: ydckYX .. section: IDLE

Remove test order dependence in idle_test.test_browser.

.. bpo: 31459 .. date: 2017-09-22-20-26-23 .. nonce: L0pnH9 .. section: IDLE

Rename IDLE's module browser from Class Browser to Module Browser. The original module-level class and method browser became a module browser, with the addition of module-level functions, years ago. Nested classes and functions were added yesterday. For back-compatibility, the virtual event <<open-class-browser>>, which appears on the Keys tab of the Settings dialog, is not changed. Patch by Cheryl Sabella.

.. bpo: 31500 .. date: 2017-09-18-10-43-03 .. nonce: Y_YDxA .. section: IDLE

Default fonts now are scaled on HiDPI displays.

.. bpo: 1612262 .. date: 2017-08-14-15-13-50 .. nonce: -x_Oyq .. section: IDLE

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

.. bpo: 28280 .. date: 2017-09-30-19-41-44 .. nonce: K_EjpO .. section: C API

Make PyMapping_Keys(), PyMapping_Values() and PyMapping_Items() always return a list (rather than a list or a tuple). Patch by Oren Milman.

.. bpo: 31532 .. date: 2017-09-20-21-59-52 .. nonce: s9Cw9_ .. section: C API

Fix memory corruption due to allocator mix in getpath.c between Py_GetPath() and Py_SetPath()

.. bpo: 25658 .. date: 2017-06-24-14-30-44 .. nonce: vm8vGE .. section: C API

Implement :pep:539 for Thread Specific Storage (TSS) API: it is a new Thread Local Storage (TLS) API to CPython which would supersede use of the existing TLS API within the CPython interpreter, while deprecating the existing API. PEP written by Erik M. Bray, patch by Masayuki Yamamoto.