+++++++++++

Python News

+++++++++++

What's New in Python 3.4.0 Beta 1?

==================================

Projected release date: 2013-11-24

Core and Builtins

-----------------

- Use the repr of a module name in more places in import, especially

exceptions.

- Issue #19619: str.encode, bytes.decode and bytearray.decode now use an

internal API to throw LookupError for known non-text encodings, rather

than attempting the encoding or decoding operation and then throwing a

TypeError for an unexpected output type. (The latter mechanism remains

in place for third party non-text encodings)

- Issue #19183: Implement PEP 456 'secure and interchangeable hash algorithm'.

Python now uses SipHash24 on all major platforms.

- Issue #12892: The utf-16* and utf-32* encoders no longer allow surrogate code

points (U+D800-U+DFFF) to be encoded. The utf-32* decoders no longer decode

byte sequences that correspond to surrogate code points. The surrogatepass

error handler now works with the utf-16* and utf-32* codecs. Based on

patches by Victor Stinner and Kang-Hao (Kenny) Lu.

- Issue #17806: Added keyword-argument support for "tabsize" to

str/bytes.expandtabs().

- Issue #17828: Output type errors in str.encode(), bytes.decode() and

bytearray.decode() now direct users to codecs.encode() or codecs.decode()

as appropriate.

- Issue #17828: The interpreter now attempts to chain errors that occur in

codec processing with a replacement exception of the same type that

includes the codec name in the error message. It ensures it only does this

when the creation of the replacement exception won't lose any information.

- Issue #19466: Clear the frames of daemon threads earlier during the

Python shutdown to call objects destructors. So "unclosed file" resource

warnings are now corretly emitted for daemon threads.

- Issue #19514: Deduplicate some _Py_IDENTIFIER declarations.

Patch by Andrei Dorian Duma.

- Issue #17936: Fix O(n**2) behaviour when adding or removing many subclasses

of a given type.

- Issue #19428: zipimport now handles errors when reading truncated or invalid

ZIP archive.

- Issue #18408: Add a new PyFrame_FastToLocalsWithError() function to handle

exceptions when merging fast locals into f_locals of a frame.

PyEval_GetLocals() now raises an exception and return NULL on failure.

- Issue #19369: Optimized the usage of __length_hint__().

- Issue #18603: Ensure that PyOS_mystricmp and PyOS_mystrnicmp are in the

Python executable and not removed by the linker's optimizer.

- Issue #19306: Add extra hints to the faulthandler module's stack

dumps that these are "upside down".

Library

-------

- Issue #19673: Add pathlib to the stdlib as a provisional module (PEP 428).

- Issue #17916: Added dis.Bytecode.from_traceback() and

dis.Bytecode.current_offset to easily display "current instruction"

markers in the new disassembly API (Patch by Claudiu Popa).

- Issue #19552: venv now supports bootstrapping pip into virtual environments

- Issue #17134: Finalize interface to Windows' certificate store. Cert and

CRL enumeration are now two functions. enum_certificates() also returns

purpose flags as set of OIDs.

- Issue #19555: Restore sysconfig.get_config_var('SO'), (and the distutils

equivalent) with a DeprecationWarning pointing people at $EXT_SUFFIX.

- Issue #8813: Add SSLContext.verify_flags to change the verification flags

of the context in order to enable certification revocation list (CRL)

checks or strict X509 rules.

- Issue #18294: Fix the zlib module to make it 64-bit safe.

- Issue #19682: Fix compatibility issue with old version of OpenSSL that

was introduced by Issue #18379.

- Issue #14455: plistlib now supports binary plists and has an updated API.

- Issue #19633: Fixed writing not compressed 16- and 32-bit wave files on

big-endian platforms.

- Issue #18379: SSLSocket.getpeercert() returns CA issuer AIA fields, OCSP

and CRL distribution points.

- Issue #18138: Implement cadata argument of SSLContext.load_verify_location()

to load CA certificates and CRL from memory. It supports PEM and DER

encoded strings.

- Issue #18775: Add name and block_size attribute to HMAC object. They now

provide the same API elements as non-keyed cryptographic hash functions.

- Issue #17276: MD5 as default digestmod for HMAC is deprecated. The HMAC

module supports digestmod names, e.g. hmac.HMAC('sha1').

- Issue #19449: in csv's writerow, handle non-string keys when generating the

error message that certain keys are not in the 'fieldnames' list.

- Issue #2927: Added the unescape() function to the html module.

- Issue #8402: Added the escape() function to the glob module.

- Issue #17618: Add Base85 and Ascii85 encoding/decoding to the base64 module.

- Issue #19634: time.strftime("%y") now raises a ValueError on AIX when given a

year before 1900.

- Fix test.support.bind_port() to not cause an error when Python was compiled

on a system with SO_REUSEPORT defined in the headers but run on a system

with an OS kernel that does not support that reasonably new socket option.

- Fix compilation error under gcc of the ctypes module bundled libffi for arm.

- Issue #19448: Add private API to SSL module to lookup ASN.1 objects by OID,

NID, short name and long name.

- Issue #19282: dbm.open now supports the context manager protocol. (Inital

patch by Claudiu Popa)

- Issue #8311: Added support for writing any bytes-like objects in the aifc,

sunau, and wave modules.

- Issue #5202: Added support for unseekable files in the wave module.

- Issue #19544 and Issue #1180: Restore global option to ignore

~/.pydistutils.cfg in Distutils, accidentally removed in backout of

distutils2 changes.

- Issue #19523: Closed FileHandler leak which occurred when delay was set.

- Issue #19544 and #6516: Restore support for --user and --group parameters to

sdist command accidentally rolled back as part of the distutils2 rollback.

- Issue #13674: Prevented time.strftime from crashing on Windows when given

a year before 1900 and a format of %y.

- Issue #19406: implementation of the ensurepip module (part of PEP 453).

Patch by Donald Stufft and Nick Coghlan.

- Issue #19544 and Issue #6286: Restore use of urllib over http allowing use

of http_proxy for Distutils upload command, a feature accidentally lost

in the rollback of distutils2.

- Issue #19544 and Issue #7457: Restore the read_pkg_file method to

distutils.dist.DistributionMetadata accidentally removed in the undo of

distutils2.

- Issue #16685: Added support for any bytes-like objects in the audioop module.

Removed support for strings.

- Issue #7171: Add Windows implementation of ``inet_ntop`` and ``inet_pton``

to socket module. Patch by Atsuo Ishimoto.

- Issue #19261: Added support for writing 24-bit samples in the sunau module.

- Issue #1097797: Added CP273 encoding, used on IBM mainframes in

Germany and Austria. Mapping provided by Michael Bierenfeld.

- Issue #1575020: Fixed support of 24-bit wave files on big-endian platforms.

- Issue #19378: Fixed a number of cases in the dis module where the new

"file" parameter was not being honoured correctly

- Issue #19378: Removed the "dis.Bytecode.show_info" method

- Issue #19378: Renamed the "dis.Bytecode.display_code" method to

"dis.Bytecode.dis" and converted it to returning a string rather than

printing output.

- Issue #19378: the "line_offset" parameter in the new "dis.get_instructions"

API has been renamed to "first_line" (and the default value and usage

changed accordingly). This should reduce confusion with the more common use

of "offset" in the dis docs to refer to bytecode offsets.

- Issue #18678: Corrected spwd struct member names in spwd module:

sp_nam->sp_namp, and sp_pwd->sp_pwdp. The old names are kept as extra

structseq members, for backward compatibility.

- Issue #6157: Fixed tkinter.Text.debug(). tkinter.Text.bbox() now raises

TypeError instead of TclError on wrong number of arguments. Original patch

by Guilherme Polo.

- Issue #10197: Rework subprocess.get[status]output to use subprocess

functionality and thus to work on Windows. Patch by Nick Coghlan

- Issue #6160: The bbox() method of tkinter.Spinbox now returns a tuple of

integers instead of a string. Based on patch by Guilherme Polo.

- Issue #19403: contextlib.redirect_stdout is now reentrant

- Issue #19286: Directories in ``package_data`` are no longer added to

the filelist, preventing failure outlined in the ticket.

- Issue #19480: HTMLParser now accepts all valid start-tag names as defined

by the HTML5 standard.

- Issue #15114: The html.parser module now raises a DeprecationWarning when the

strict argument of HTMLParser or the HTMLParser.error method are used.

- Issue #19410: Undo the special-casing removal of '' for

importlib.machinery.FileFinder.

- Issue #19424: Fix the warnings module to accept filename containing surrogate

characters.

- Issue #19435: Fix directory traversal attack on CGIHttpRequestHandler.

- Issue #19227: Remove pthread_atfork() handler. The handler was added to

solve #18747 but has caused issues.

- Issue #19420: Fix reference leak in module initalization code of

_hashopenssl.c

- Issue #19329: Optimized compiling charsets in regular expressions.

- Issue #19227: Try to fix deadlocks caused by re-seeding then OpenSSL

pseudo-random number generator on fork().

- Issue #16037: HTTPMessage.readheaders() raises an HTTPException when more than

100 headers are read. Adapted from patch by Jyrki Pulliainen.

- Issue #16040: CVE-2013-1752: nntplib: Limit maximum line lengths to 2048 to

prevent readline() calls from consuming too much memory. Patch by Jyrki

Pulliainen.

- Issue #16041: CVE-2013-1752: poplib: Limit maximum line lengths to 2048 to

prevent readline() calls from consuming too much memory. Patch by Jyrki

Pulliainen.

- Issue #17997: Change behavior of ``ssl.match_hostname()`` to follow RFC 6125,

for security reasons. It now doesn't match multiple wildcards nor wildcards

inside IDN fragments.

- Issue #16039: CVE-2013-1752: Change use of readline in imaplib module to limit

line length. Patch by Emil Lind.

- Issue #19330: the unnecessary wrapper functions have been removed from the

implementations of the new contextlib.redirect_stdout and

contextlib.suppress context managers, which also ensures they provide

reasonable help() output on instances

- Issue #19393: Fix symtable.symtable function to not be confused when there are

functions or classes named "top".

- Issue #18685: Restore re performance to pre-PEP 393 levels.

- Issue #19339: telnetlib module is now using time.monotonic() when available

to compute timeout.

- Issue #19399: fix sporadic test_subprocess failure.

- Issue #13234: Fix os.listdir to work with extended paths on Windows.

Patch by Santoso Wijaya.

- Issue #19375: The site module adding a "site-python" directory to sys.path,

if it exists, is now deprecated.

- Issue #19379: Lazily import linecache in the warnings module, to make

startup with warnings faster until a warning gets printed.

- Issue #19288: Fixed the "in" operator of dbm.gnu databases for string

argument. Original patch by Arfrever Frehtes Taifersar Arahesis.

- Issue #19287: Fixed the "in" operator of dbm.ndbm databases for string

argument. Original patch by Arfrever Frehtes Taifersar Arahesis.

- Issue #19327: Fixed the working of regular expressions with too big charset.

- Issue #17400: New 'is_global' attribute for ipaddress to tell if an address

is allocated by IANA for global or private networks.

- Issue #19350: Increasing the test coverage of macurl2path. Patch by Colin

Williams.

- Issue #19365: Optimized the parsing of long replacement string in re.sub*()

functions.

- Issue #19352: Fix unittest discovery when a module can be reached

through several paths (e.g. under Debian/Ubuntu with virtualenv).

- Issue #15207: Fix mimetypes to read from correct part of Windows registry

Original patch by Dave Chambers

- Issue #16595: Add prlimit() to resource module.

- Issue #19324: Expose Linux-specific constants in resource module.

- Issue #17400: ipaddress should make it easy to identify rfc6598 addresses.

- Load SSL's error strings in hashlib.

- Issue #18527: Upgrade internal copy of zlib to 1.2.8.

- Issue #19274: Add a filterfunc parameter to PyZipFile.writepy.

- Issue #8964: fix platform._sys_version to handle IronPython 2.6+.

Patch by Martin Matusiak.

- Issue #19413: Restore pre-3.3 reload() semantics of re-finding modules.

- Issue #18958: Improve error message for json.load(s) while passing a string

that starts with a UTF-8 BOM.

- Issue #19307: Improve error message for json.load(s) while passing objects

of the wrong type.

- Issue #16038: CVE-2013-1752: ftplib: Limit amount of data read by

limiting the call to readline(). Original patch by Michał

Jastrzębski and Giampaolo Rodola.

- Issue #17087: Improved the repr for regular expression match objects.

Tests

-----

- Issue #19664: test_userdict's repr test no longer depends on the order

of dict elements.

- Issue #19440: Clean up test_capi by removing an unnecessary __future__

import, converting from test_main to unittest.main, and running the

_testcapi module tests as subTests of a unittest TestCase method.

- Issue #19378: the main dis module tests are now run with both stdout

redirection *and* passing an explicit file parameter

- Issue #19378: removed the not-actually-helpful assertInstructionMatches

and assertBytecodeExactlyMatches helpers from bytecode_helper

- Issue #18702: All skipped tests now reported as skipped.

- Issue #19439: interpreter embedding tests are now executed on Windows

(Patch by Zachary Ware)

- Issue #19085: Added basic tests for all tkinter widget options.

- Issue 19384: Fix test_py_compile for root user, patch by Claudiu Popa.

Documentation

-------------

- Issue #18326: Clarify that list.sort's arguments are keyword-only. Also,

attempt to reduce confusion in the glossary by not saying there are

different "types" of arguments and parameters.

Build

-----

- Update SQLite to 3.8.1 and xz to 5.0.5 on Windows.

- Issue #16632: Enable DEP and ASLR on Windows.

- Issue #17791: Drop PREFIX and EXEC_PREFIX definitions from PC/pyconfig.h

- Add workaround for VS 2010 nmake clean issue. VS 2010 doesn't set up PATH

for nmake.exe correctly.

- Issue #19550: Implement Windows installer changes of PEP 453 (ensurepip).

- Issue #19520: Fix compiler warning in the _sha3 module on 32bit Windows.

- Issue #19356: Avoid using a C variabled named "_self", it's a reserved

word in some C compilers.

- Issue #15792: Correct build options on Win64. Patch by Jeremy Kloth.

- Issue #19373: Apply upstream change to Tk 8.5.15 fixing OS X 10.9

screen refresh problem for OS X installer build.

- Issue #19649: On OS X, the same set of file names are now installed

in bin directories for all configurations: non-framework vs framework,

and single arch vs universal builds. pythonx.y-32 is now always

installed for 64-bit/32-bit universal builds. The obsolete and

undocumented pythonw* symlinks are no longer installed anywhere.

- Issue #19553: PEP 453 - "make install" and "make altinstall" now install or

upgrade pip by default, using the bundled pip provided by the new ensurepip

module. A new configure option, --with-ensurepip[=upgrade|install|no], is

available to override the default ensurepip "--upgrade" option. The option

can also be set with "make [alt]install ENSUREPIP=[upgrade|install\no]".

Tools/Demos

-----------

- Issue #19552: pyvenv now bootstraps pip into virtual environments by

default (pass --without-pip to request the old behaviour)

- Issue #19390: Argument Clinic no longer accepts malformed Python

and C ids.

What's New in Python 3.4.0 Alpha 4?

===================================

Release date: 2013-10-20

Core and Builtins

-----------------

- Issue #19301: Give classes and functions that are explicitly marked global a

global qualname.

- Issue #19279: UTF-7 decoder no longer produces illegal strings.

- Issue #16612: Add "Argument Clinic", a compile-time preprocessor for

C files to generate argument parsing code. (See PEP 436.)

- Issue #18810: Shift stat calls in importlib.machinery.FileFinder such that

the code is optimistic that if something exists in a directory named exactly

like the possible package being searched for that it's in actuality a

directory.

- Issue #18416: importlib.machinery.PathFinder now treats '' as the cwd and

importlib.machinery.FileFinder no longer special-cases '' to '.'. This leads

to modules imported from cwd to now possess an absolute file path for

__file__ (this does not affect modules specified by path on the CLI but it

does affect -m/runpy). It also allows FileFinder to be more consistent by not

having an edge case.

- Issue #4555: All exported C symbols are now prefixed with either

"Py" or "_Py".

- Issue #19219: Speed up marshal.loads(), and make pyc files slightly

(5% to 10%) smaller.

- Issue #19221: Upgrade Unicode database to version 6.3.0.

- Issue #16742: The result of the C callback PyOS_ReadlineFunctionPointer must

now be a string allocated by PyMem_RawMalloc() or PyMem_RawRealloc() (or NULL

if an error occurred), instead of a string allocated by PyMem_Malloc() or

PyMem_Realloc().

- Issue #19199: Remove ``PyThreadState.tick_counter`` field

- Fix macro expansion of _PyErr_OCCURRED(), and make sure to use it in at

least one place so as to avoid regressions.

- Issue #19087: Improve bytearray allocation in order to allow cheap popping

of data at the front (slice deletion).

- Issue #19014: memoryview.cast() is now allowed on zero-length views.

- Issue #18690: memoryview is now automatically registered with

collections.abc.Sequence

- Issue #19078: memoryview now correctly supports the reversed builtin

(Patch by Claudiu Popa)

Library

-------

- Issue #18235: Fix the sysconfig variables LDSHARED and BLDSHARED under AIX.

Patch by David Edelsohn.

- Issue #18606: Add the new "statistics" module (PEP 450). Contributed

by Steven D'Aprano.

- Issue #12866: The audioop module now supports 24-bit samples.

- Issue #19254: Provide an optimized Python implementation of pbkdf2_hmac.

- Issues #19201, #19222, #19223: Add "x" mode (exclusive creation) in opening

file to bz2, gzip and lzma modules. Patches by Tim Heaney and Vajrasky Kok.

- Fix a reference count leak in _sre.

- Issue #19262: Initial check in of the 'asyncio' package (a.k.a. Tulip,

a.k.a. PEP 3156). There are no docs yet, and the PEP is slightly

out of date with the code. This module will have *provisional* status

in Python 3.4.

- Issue #19276: Fixed the wave module on 64-bit big-endian platforms.

- Issue #19266: Rename the new-in-3.4 ``contextlib.ignore`` context manager

to ``contextlib.suppress`` in order to be more consistent with existing

descriptions of that operation elsewhere in the language and standard

library documentation (Patch by Zero Piraeus).

- Issue #18891: Completed the new email package (provisional) API additions

by adding new classes EmailMessage, MIMEPart, and ContentManager.

- Issue #18281: Unused stat constants removed from `tarfile`.

- Issue #18468: The re.split, re.findall, and re.sub functions and the group()

and groups() methods of match object now always return a string or a bytes

object.

- Issue #18725: The textwrap module now supports truncating multiline text.

- Issue #18776: atexit callbacks now display their full traceback when they

raise an exception.

- Issue #17827: Add the missing documentation for ``codecs.encode`` and

``codecs.decode``.

- Issue #19218: Rename collections.abc to _collections_abc in order to

speed up interpreter start.

- Issue #18582: Add 'pbkdf2_hmac' to the hashlib module. It implements PKCS#5

password-based key derivation functions with HMAC as pseudorandom function.

- Issue #19131: The aifc module now correctly reads and writes sampwidth of

compressed streams.

- Issue #19209: Remove import of copyreg from the os module to speed up

interpreter startup. stat_result and statvfs_result are now hard-coded to

reside in the os module.

- Issue #19205: Don't import the 're' module in site and sysconfig module to

to speed up interpreter start.

- Issue #9548: Add a minimal "_bootlocale" module that is imported by the

_io module instead of the full locale module.

- Issue #18764: remove the 'print' alias for the PDB 'p' command so that it no

longer shadows the print function.

- Issue #19158: a rare race in BoundedSemaphore could allow .release() too

often.

- Issue #15805: Add contextlib.redirect_stdout().

- Issue #18716: Deprecate the formatter module.

- Issue #18037: 2to3 now escapes '\u' and '\U' in native strings.

- Issue #17839: base64.decodebytes and base64.encodebytes now accept any

object that exports a 1 dimensional array of bytes (this means the same

is now also true for base64_codec)

- Issue #19132: The pprint module now supports compact mode.

- Issue #19137: The pprint module now correctly formats instances of set and

frozenset subclasses.

- Issue #10042: functools.total_ordering now correctly handles

NotImplemented being returned by the underlying comparison function (Patch

by Katie Miller)

- Issue #19092: contextlib.ExitStack now correctly reraises exceptions

from the __exit__ callbacks of inner context managers (Patch by Hrvoje

Nikšić)

- Issue #12641: Avoid passing "-mno-cygwin" to the mingw32 compiler, except

when necessary. Patch by Oscar Benjamin.

- Issue #5845: In site.py, only load readline history from ~/.python_history

if no history has been read already. This avoids double writes to the

history file at shutdown.

- Properly initialize all fields of a SSL object after allocation.

- Issue #19095: SSLSocket.getpeercert() now raises ValueError when the

SSL handshake hasn't been done.

- Issue #4366: Fix building extensions on all platforms when --enable-shared

is used.

- Issue #19030: Fixed `inspect.getmembers` and `inspect.classify_class_attrs`

to attempt activating descriptors before falling back to a __dict__ search

for faulty descriptors. `inspect.classify_class_attrs` no longer returns

Attributes whose home class is None.

C API

-----

- Issue #1772673: The type of `char*` arguments now changed to `const char*`.

- Issue #16129: Added a `Py_SetStandardStreamEncoding` pre-initialization API

to allow embedding applications like Blender to force a particular

encoding and error handler for the standard IO streams (initial patch by

Bastien Montagne)

Tests

-----

- Issue #19275: Fix test_site on AMD64 Snow Leopard

- Issue #14407: Fix unittest test discovery in test_concurrent_futures.

- Issue #18919: Unified and extended tests for audio modules: aifc, sunau and

wave.

- Issue #18714: Added tests for ``pdb.find_function()``.

Documentation

-------------

- Issue #18758: Fixed and improved cross-references.

- Issue #18972: Modernize email examples and use the argparse module in them.

Build

-----

- Issue #19130: Correct PCbuild/readme.txt, Python 3.3 and 3.4 require VS 2010.

- Issue #15663: Update OS X 10.6+ installer to use Tcl/Tk 8.5.15.

- Issue #14499: Fix several problems with OS X universal build support:

1. ppc arch detection for extension module builds broke with Xcode 5

2. ppc arch detection in configure did not work on OS X 10.4

3. -sysroot and -arch flags were unnecessarily duplicated

4. there was no obvious way to configure an intel-32 only build.

- Issue #19019: Change the OS X installer build script to use CFLAGS instead

of OPT for special build options. By setting OPT, some compiler-specific

options like -fwrapv were overridden and thus not used, which could result

in broken interpreters when building with clang.

What's New in Python 3.4.0 Alpha 3?

===================================

Release date: 2013-09-29

Core and Builtins

-----------------

- Issue #18818: The "encodingname" part of PYTHONIOENCODING is now optional.

- Issue #19098: Prevent overflow in the compiler when the recursion limit is set

absurdly high.

Library

-------

- Issue #18929: `inspect.classify_class_attrs()` now correctly finds class

attributes returned by `dir()` that are located in the metaclass.

- Issue #18950: Fix miscellaneous bugs in the sunau module.

Au_read.readframes() now updates current file position and reads correct

number of frames from multichannel stream. Au_write.writeframesraw() now

correctly updates current file position. Au_read.getnframes() now returns an

integer (as in Python 2). Au_read and Au_write now correctly works with file

object if start file position is not a zero.

- Issue #18594: The fast path for collections.Counter() was never taken

due to an over-restrictive type check.

- Issue #19053: ZipExtFile.read1() with non-zero argument no more returns empty

bytes until end of data.

- logging: added support for Unix domain sockets to SocketHandler and

DatagramHandler.

- Issue #18996: TestCase.assertEqual() now more cleverly shorten differing

strings in error report.

- Issue #19034: repr() for tkinter.Tcl_Obj now exposes string reperesentation.

- Issue #18978: ``urllib.request.Request`` now allows the method to be

indicated on the class and no longer sets it to None in ``__init__``.

- Issue #18626: the inspect module now offers a basic command line

introspection interface (Initial patch by Claudiu Popa)

- Issue #3015: Fixed tkinter with wantobject=False. Any Tcl command call

returned empty string.

- Issue #19037: The mailbox module now makes all changes to maildir files

before moving them into place, to avoid race conditions with other programs

that may be accessing the maildir directory.

- Issue #14984: On POSIX systems, when netrc is called without a filename

argument (and therefore is reading the user's $HOME/.netrc file), it now

enforces the same security rules as typical ftp clients: the .netrc file must

be owned by the user that owns the process and must not be readable by any

other user.

- Issue #18873: The tokenize module now detects Python source code encoding

only in comment lines.

- Issue #17764: Enable http.server to bind to a user specified network

interface. Patch contributed by Malte Swart.

- Issue #18937: Add an assertLogs() context manager to unittest.TestCase

to ensure that a block of code emits a message using the logging module.

- Issue #17324: Fix http.server's request handling case on trailing '/'. Patch

contributed by Vajrasky Kok.

- Issue #19018: The heapq.merge() function no longer suppresses IndexError

in the underlying iterables.

- Issue #18784: The uuid module no more attempts to load libc via ctypes.CDLL,

if all necessary functions are already found in libuuid.

Patch by Evgeny Sologubov.

- The :envvar:`PYTHONFAULTHANDLER` environment variable now only enables the

faulthandler module if the variable is non-empty. Same behaviour than other

variables like :envvar:`PYTHONDONTWRITEBYTECODE`.

- Issue #1565525: New function ``traceback.clear_frames`` will clear

the local variables of all the stack frames referenced by a traceback

object.

Tests

-----

- Issue #18952: Fix regression in support data downloads introduced when

test.support was converted to a package. Regression noticed by Zachary

Ware.

IDLE

----

- Issue #18873: IDLE now detects Python source code encoding only in comment

lines.

- Issue #18988: The "Tab" key now works when a word is already autocompleted.

Documentation

-------------

- Issue #17003: Unified the size argument names in the io module with common

practice.

Build

-----

- Issue #18596: Support the use of address sanity checking in recent versions

of clang and GCC by appropriately marking known false alarms in the small

object allocator. Patch contributed by Dhiru Kholia.

Tools/Demos

-----------

- Issue #18873: 2to3 and the findnocoding.py script now detect Python source

code encoding only in comment lines.

What's New in Python 3.4.0 Alpha 2?

===================================

Release date: 2013-09-09

Core and Builtins

-----------------

- Issue #18942: sys._debugmallocstats() output was damaged on Windows.

- Issue #18780: %-formatting now prints value instead of str for

int subclasses when using %d, %i, and %u codes.

- Issue #18571: Implementation of the PEP 446: file descriptors and file

handles are now created non-inheritable; add functions

os.get/set_inheritable(), os.get/set_handle_inheritable() and

socket.socket.get/set_inheritable().

- Issue #11619: The parser and the import machinery do not encode Unicode

filenames anymore on Windows.

- Issue #18808: Non-daemon threads are now automatically joined when

a sub-interpreter is shutdown (it would previously dump a fatal error).

- Remove supporting for compiling on systems without getcwd().

- Issue #18774: Remove last bits of GNU PTH thread code and thread_pth.h.

- Issue #18771: Add optimization to set object lookups to reduce the cost

of hash collisions. The core idea is to inspect a second key/hash pair

for each cache line retrieved.

- Issue #16105: When a signal handler fails to write to the file descriptor

registered with ``signal.set_wakeup_fd()``, report an exception instead

of ignoring the error.

- Issue #18722: Remove uses of the "register" keyword in C code.

- Issue #18667: Add missing "HAVE_FCHOWNAT" symbol to posix._have_functions.

- Issue #16499: Add command line option for isolated mode.

- Issue #15301: Parsing fd, uid, and gid parameters for builtins

in Modules/posixmodule.c is now far more robust.

- Issue #18368: PyOS_StdioReadline() no longer leaks memory when realloc()

fail.

- Issue #17934: Add a clear() method to frame objects, to help clean up

expensive details (local variables) and break reference cycles.

- Issue #18780: %-formatting codes %d, %i, and %u now treat int-subclasses

as int (displays value of int-subclass instead of str(int-subclass) ).

Library

-------

- Issue #18808: Thread.join() now waits for the underlying thread state to

be destroyed before returning. This prevents unpredictable aborts in

Py_EndInterpreter() when some non-daemon threads are still running.

- Issue #18458: Prevent crashes with newer versions of libedit. Its readline

emulation has changed from 0-based indexing to 1-based like gnu readline.

- Issue #18852: Handle case of ``readline.__doc__`` being ``None`` in the new

readline activation code in ``site.py``.

- Issue #18672: Fixed format specifiers for Py_ssize_t in debugging output in

the _sre module.

- Issue #18830: inspect.getclasstree() no more produces duplicated entries even

when input list contains duplicates.

- Issue #18878: sunau.open now supports the context manager protocol. Based on

patches by Claudiu Popa and R. David Murray.

- Issue #18909: Fix _tkinter.tkapp.interpaddr() on Windows 64-bit, don't cast

64-bit pointer to long (32 bits).

- Issue #18876: The FileIO.mode attribute now better reflects the actual mode

under which the file was opened. Patch by Erik Bray.

- Issue #16853: Add new selectors module.

- Issue #18882: Add threading.main_thread() function.

- Issue #18901: The sunau getparams method now returns a namedtuple rather than

a plain tuple. Patch by Claudiu Popa.

- Issue #17487: The result of the wave getparams method now is pickleable again.

Patch by Claudiu Popa.

- Issue #18756: os.urandom() now uses a lazily-opened persistent file

descriptor, so as to avoid using many file descriptors when run in

parallel from multiple threads.

- Issue #18418: After fork(), reinit all threads states, not only active ones.

Patch by A. Jesse Jiryu Davis.

- Issue #17974: Switch unittest from using getopt to using argparse.

- Issue #11798: TestSuite now drops references to own tests after execution.

- Issue #16611: http.cookie now correctly parses the 'secure' and 'httponly'

cookie flags.

- Issue #11973: Fix a problem in kevent. The flags and fflags fields are now

properly handled as unsigned.

- Issue #18807: ``pyvenv`` now takes a --copies argument allowing copies

instead of symlinks even where symlinks are available and the default.

- Issue #18538: ``python -m dis`` now uses argparse for argument processing.

Patch by Michele Orrù.

- Issue #18394: Close cgi.FieldStorage's optional file.

- Issue #17702: On error, os.environb now removes suppress the except context

when raising a new KeyError with the original key.

- Issue #16809: Fixed some tkinter incompabilities with Tcl/Tk 8.6.

- Issue #16809: Tkinter's splitlist() and split() methods now accept Tcl_Obj

argument.

- Issue #18324: set_payload now correctly handles binary input. This also

supersedes the previous fixes for #14360, #1717, and #16564.

- Issue #18794: Add a fileno() method and a closed attribute to select.devpoll

objects.

- Issue #17119: Fixed integer overflows when processing large strings and tuples

in the tkinter module.

- Issue #18747: Re-seed OpenSSL's pseudo-random number generator after fork.

A pthread_atfork() parent handler is used to seed the PRNG with pid, time

and some stack data.

- Issue #8865: Concurrent invocation of select.poll.poll() now raises a

RuntimeError exception. Patch by Christian Schubert.

- Issue #18777: The ssl module now uses the new CRYPTO_THREADID API of

OpenSSL 1.0.0+ instead of the deprecated CRYPTO id callback function.

- Issue #18768: Correct doc string of RAND_edg(). Patch by Vajrasky Kok.

- Issue #18178: Fix ctypes on BSD. dlmalloc.c was compiled twice which broke

malloc weak symbols.

- Issue #18709: Fix CVE-2013-4238. The SSL module now handles NULL bytes

inside subjectAltName correctly. Formerly the module has used OpenSSL's

GENERAL_NAME_print() function to get the string represention of ASN.1

strings for ``rfc822Name`` (email), ``dNSName`` (DNS) and

``uniformResourceIdentifier`` (URI).

- Issue #18701: Remove support of old CPython versions (<3.0) from C code.

- Issue #18756: Improve error reporting in os.urandom() when the failure

is due to something else than /dev/urandom not existing (for example,

exhausting the file descriptor limit).

- Issue #18673: Add O_TMPFILE to os module. O_TMPFILE requires Linux kernel

3.11 or newer. It's only defined on system with 3.11 uapi headers, too.

- Issue #18532: Change the builtin hash algorithms' names to lower case names

as promised by hashlib's documentation.

- Issue #18405: Improve the entropy of crypt.mksalt().

- Issue #12015: The tempfile module now uses a suffix of 8 random characters

instead of 6, to reduce the risk of filename collision. The entropy was

reduced when uppercase letters were removed from the charset used to generate

random characters.

- Issue #18585: Add :func:`textwrap.shorten` to collapse and truncate a

piece of text to a given length.

- Issue #18598: Tweak exception message for importlib.import_module() to

include the module name when a key argument is missing.

- Issue #19151: Fix docstring and use of _get_supported_file_loaders() to

reflect 2-tuples.

- Issue #19152: Add ExtensionFileLoader.get_filename().

- Issue #18676: Change 'positive' to 'non-negative' in queue.py put and get

docstrings and ValueError messages. Patch by Zhongyue Luo

- Fix refcounting issue with extension types in tkinter.

- Issue #8112: xlmrpc.server's DocXMLRPCServer server no longer raises an error

if methods have annotations; it now correctly displays the annotations.

- Issue #18600: Added policy argument to email.message.Message.as_string,

and as_bytes and __bytes__ methods to Message.

- Issue #18671: Output more information when logging exceptions occur.

- Issue #18621: Prevent the site module's patched builtins from keeping

too many references alive for too long.

- Issue #4885: Add weakref support to mmap objects. Patch by Valerie Lambert.

- Issue #8860: Fixed rounding in timedelta constructor.

- Issue #18849: Fixed a Windows-specific tempfile bug where collision with an

existing directory caused mkstemp and related APIs to fail instead of

retrying. Report and fix by Vlad Shcherbina.

- Issue #18920: argparse's default destination for the version action (-v,

--version) has also been changed to stdout, to match the Python executable.

Tests

-----

- Issue #18623: Factor out the _SuppressCoreFiles context manager into

test.support. Patch by Valerie Lambert.

- Issue #12037: Fix test_email for desktop Windows.

- Issue #15507: test_subprocess's test_send_signal could fail if the test

runner were run in an environment where the process inherited an ignore

setting for SIGINT. Restore the SIGINT handler to the desired

KeyboardInterrupt raising one during that test.

- Issue #16799: Switched from getopt to argparse style in regrtest's argument

parsing. Added more tests for regrtest's argument parsing.

- Issue #18792: Use "127.0.0.1" or "::1" instead of "localhost" as much as

possible, since "localhost" goes through a DNS lookup under recent Windows

versions.

IDLE

----

- Issue #18489: Add tests for SearchEngine. Original patch by Phil Webster.

Documentation

-------------

- Issue #18743: Fix references to non-existant "StringIO" module.

- Issue #18783: Removed existing mentions of Python long type in docstrings,

error messages and comments.

Build

-----

- Issue #1584: Provide configure options to override default search paths for

Tcl and Tk when building _tkinter.

- Issue #15663: Tcl/Tk 8.5.14 is now included with the OS X 10.6+ 64-/32-bit

installer. It is no longer necessary to install a third-party version of

Tcl/Tk 8.5 to work around the problems in the Apple-supplied Tcl/Tk 8.5