Python Changelog

What's new in Python 3.7.0

Aug 1, 2018

PEP 539, new C API for thread-local storage
PEP 545, Python documentation translations
New documentation translations: Japanese, French, and Korean.
PEP 552, Deterministic pyc files
PEP 553, Built-in breakpoint()
PEP 557, Data Classes
PEP 560, Core support for typing module and generic types
PEP 562, Customization of access to module attributes
PEP 563, Postponed evaluation of annotations
PEP 564, Time functions with nanosecond resolution
PEP 565, Improved DeprecationWarning handling
PEP 567, Context Variables
Avoiding the use of ASCII as a default text encoding (PEP 538, legacy C locale coercion and PEP 540, forced UTF-8 runtime mode)
The insertion-order preservation nature of dict objects is now an official part of the Python language spec.
Notable performance improvements in many areas.

New in Python 3.6.4 (Dec 19, 2017)

New in Python 3.6.3 (Oct 4, 2017)

New in Python 3.6.2 (Jul 17, 2017)

New in Python 3.6.0 (Dec 23, 2016)

New in Python 3.6.0 Beta 2 (Oct 11, 2016)

New in Python 3.6.0 Alpha 3 (Jul 12, 2016)

New in Python 3.5.2 (Jun 27, 2016)

New in Python 3.5.1 (Dec 7, 2015)

Core and Builtins:
Issue #25709: Fixed problem with in-place string concatenation and utf-8 cache.
Issue #24097: Fixed crash in object.__reduce__() if slot name is freed inside __getattr__.
Issue #24731: Fixed crash on converting objects with special methods __bytes__, __trunc__, and __float__ returning instances of subclasses of bytes, int, and float to subclasses of bytes, int, and float correspondingly.
Library:
Issue #25717: Restore the previous behaviour of tolerating most fstat() errors when opening files. This was a regression in 3.5a1, and stopped anonymous temporary files from working in special cases.
Issue #24903: Fix regression in number of arguments compileall accepts when ‘-d’ is specified. The check on the number of arguments has been dropped completely as it never worked correctly anyway.
Issue #25764: In the subprocess module, preserve any exception caused by fork() failure when preexec_fn is used.
Issue #6478: _strptime’s regexp cache now is reset after changing timezone with time.tzset().
Issue #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 back to the caller, rather than raising ImportError.
Issue #25177: Fixed problem with the mean of very small and very large numbers. As a side effect, statistics.mean and statistics.variance should be significantly faster.
Issue #25718: Fixed copying object with state with boolean value is false.
Issue #10131: Fixed deep copying of minidom documents. Based on patch by Marian Ganisin.
Issue #25725: Fixed a reference leak in pickle.loads() when unpickling invalid data including tuple instructions.
Issue #25663: In the Readline completer, avoid listing duplicate global names, and search the global namespace before searching builtins.
Issue #25688: Fixed file leak in ElementTree.iterparse() raising an error.
Issue #23914: Fixed SystemError raised by unpickler on broken pickle data.
Issue #25691: Fixed crash on deleting ElementTree.Element attributes.
Issue #25624: ZipFile now always writes a ZIP_STORED header for directory entries. Patch by Dingyuan Wang.

New in Python 2.7.11 (Dec 7, 2015)

Core and BuiltinsL:
Issue #25678: Avoid buffer overreads when int(), long(), float(), and
compile() are passed buffer objects. These objects are not necessarily
terminated by a null byte, but the functions assumed they were.
Issue #25388: Fixed tokenizer hang when processing undecodable source code
with a null byte.
Issue #22995: Default implementation of __reduce__ and __reduce_ex__ now
rejects builtin types with not defined __new__.
Issue #7267: format(int, 'c') now raises OverflowError when the argument is
not in range(0, 256).
Issue #24806: Prevent builtin types that are not allowed to be subclassed from
being subclassed through multiple inheritance.
Issue #24848: Fixed a number of bugs in UTF-7 decoding of misformed data.
Issue #25003: os.urandom() doesn't use getentropy() on Solaris because
getentropy() is blocking, whereas os.urandom() should not block. getentropy()
is supported since Solaris 11.3.
Issue #21167: NAN operations are now handled correctly when python is
compiled with ICC even if -fp-model strict is not specified.
Issue #24467: Fixed possible buffer over-read in bytearray. The bytearray
object now always allocates place for trailing null byte and it's buffer now
is always null-terminated.
Issue #19543: encode() and decode() methods and constructors of str,
unicode and bytearray classes now emit deprecation warning for known
non-text encodings when Python is ran with the -3 option.
Issue #24115: Update uses of PyObject_IsTrue(), PyObject_Not(),
PyObject_IsInstance(), PyObject_RichCompareBool() and _PyDict_Contains()
to check for and handle errors correctly.
Issue #4753: On compilers where it is supported, use "computed gotos" for
bytecode dispatch in the interpreter. This improves interpretation
performance.
Issue #22939: Fixed integer overflow in iterator object. Original patch by
Clement Rouault.
Issue #24102: Fixed exception type checking in standard error handlers.
Library:
Issue #10128: backport issue #10845's mitigation of incompatibilities between
the multiprocessing module and directory and zipfile execution.
Multiprocessing on Windows will now automatically skip rerunning __main__ in
spawned processes, rather than failing with AssertionError.
Issue #25578: Fix (another) memory leak in SSLSocket.getpeercer().
Issue #25590: In the Readline completer, only call getattr() once per
attribute.
Issue #25530: Disable the vulnerable SSLv3 protocol by default when creating
ssl.SSLContext.
Issue #25569: Fix memory leak in SSLSocket.getpeercert().
Issue #7759: Fixed the mhlib module on filesystems that doesn't support
link counting for directories.
Issue #892902: Fixed pickling recursive objects.
Issue #18010: Fix the pydoc GUI's search function to handle exceptions
from importing packages.
Issue #25515: Always use os.urandom as a source of randomness in uuid.uuid4.
Issue #21827: Fixed textwrap.dedent() for the case when largest common
whitespace is a substring of smallest leading whitespace.
Based on patch by Robert Li.
Issue #21709: Fix the logging module to not depend upon __file__ being set
properly to get the filename of its caller from the stack. This allows it
to work if run in a frozen or embedded environment where the module's
.__file__ attribute does not match its code object's .co_filename.
Issue #25319: When threading.Event is reinitialized, the underlying condition
should use a regular lock rather than a recursive lock.
Issue #25232: Fix CGIRequestHandler to split the query from the URL at the
first question mark (?) rather than the last. Patch from Xiang Zhang.
Issue #24657: Prevent CGIRequestHandler from collapsing slashes in the
query part of the URL as if it were a path. Patch from Xiang Zhang.
Issue #22958: Constructor and update method of weakref.WeakValueDictionary
now accept the self keyword argument.
Issue #22609: Constructor and the update method of collections.UserDict now
accept the self keyword argument.
Issue #25203: Failed readline.set_completer_delims() no longer left the
module in inconsistent state.
Issue #19143: platform module now reads Windows version from kernel32.dll to
avoid compatibility shims.
Issue #25135: Make deque_clear() safer by emptying the deque before clearing.
This helps avoid possible reentrancy issues.
Issue #24684: socket.socket.getaddrinfo() now calls
PyUnicode_AsEncodedString() instead of calling the encode() method of the
host, to handle correctly custom unicode string with an encode() method
which doesn't return a byte string. The encoder of the IDNA codec is now
called directly instead of calling the encode() method of the string.
Issue #24982: shutil.make_archive() with the "zip" format now adds entries
for directories (including empty directories) in ZIP file.
Issue #17849: Raise a sensible exception if an invalid response is
received for a HTTP tunnel request, as seen with some servers that
do not support tunnelling. Initial patch from Cory Benfield.
Issue #16180: Exit pdb if file has syntax error, instead of trapping user
in an infinite loop. Patch by Xavier de Gaye.
Issue #22812: Fix unittest discovery examples.
Patch from Pam McA'Nulty.
Issue #24634: Importing uuid should not try to load libc on Windows
Issue #23652: Make it possible to compile the select module against the
libc headers from the Linux Standard Base, which do not include some
EPOLL macros. Initial patch by Matt Frank.
Issue #15138: Speed up base64.urlsafe_b64{en,de}code considerably.
Issue #23319: Fix ctypes.BigEndianStructure, swap correctly bytes. Patch
written by Matthieu Gautier.
Issue #23254: Document how to close the TCPServer listening socket.
Patch from Martin Panter.
Issue #17527: Add PATCH to wsgiref.validator. Patch from Luca Sbardella.
Issue #24613: Calling array.fromstring() with self is no longer allowed
to prevent the use-after-free error. Patch by John Leitch.
Issue #24708: Fix possible integer overflow in strop.replace().
Issue #24620: Random.setstate() now validates the value of state last element.
Issue #13938: 2to3 converts StringTypes to a tuple. Patch from Mark Hammond.
Issue #24611: Fixed compiling the posix module on non-Windows platforms
without mknod() or makedev() (e.g. on Unixware).
Issue #18684: Fixed reading out of the buffer in the re module.
Issue #24259: tarfile now raises a ReadError if an archive is truncated
inside a data segment.
Issue #24514: tarfile now tolerates number fields consisting of only
whitespace.
Issue #20387: Restore semantic round-trip correctness in tokenize/untokenize
for tab-indented blocks.
Issue #24456: Fixed possible buffer over-read in adpcm2lin() and lin2adpcm()
functions of the audioop module. Fixed SystemError when the state is not a
tuple. Fixed possible memory leak.
Issue #24481: Fix possible memory corruption with large profiler info strings
in hotshot.
Issue #24489: ensure a previously set C errno doesn't disturb cmath.polar().
Issue #19543: io.TextIOWrapper (and hence io.open()) now uses the internal
codec marking system added to emit deprecation warning for known non-text
encodings at stream construction time when Python is ran with the -3 option.
Issue #24264: Fixed buffer overflow in the imageop module.
Issue #5633: Fixed timeit when the statement is a string and the setup is not.
Issue #24326: Fixed audioop.ratecv() with non-default weightB argument.
Original patch by David Moore.
Issue #22095: Fixed HTTPConnection.set_tunnel with default port. The port
value in the host header was set to "None". Patch by Demian Brecht.
Issue #24257: Fixed segmentation fault in sqlite3.Row constructor with faked
cursor type.
Issue #24286: Dict view were not registered with the MappingView abstract
base classes. This caused key and item views in OrderedDict to not be equal
to their regular dict counterparts.
Issue #22107: tempfile.gettempdir() and tempfile.mkdtemp() now try again
when a directory with the chosen name already exists on Windows as well as
on Unix. tempfile.mkstemp() now fails early if parent directory is not
valid (not exists or is a file) on Windows.
Issue #6598: Increased time precision and random number range in
email.utils.make_msgid() to strengthen the uniqueness of the message ID.
Issue #24091: Fixed various crashes in corner cases in cElementTree.
Issue #15267: HTTPConnection.request() now is compatibile with old-style
classes (such as TemporaryFile). Original patch by Atsuo Ishimoto.
Issue #20014: array.array() now accepts unicode typecodes. Based on patch by
Vajrasky Kok.
Issue #23637: Showing a warning no longer fails with UnicodeErrror.
Formatting unicode warning in the file with the path containing non-ascii
characters no longer fails with UnicodeErrror.
Issue #24134: Reverted issue #24134 changes.
IDLE:
Issue 15348: Stop the debugger engine (normally in a user process)
before closing the debugger window (running in the IDLE process).
This prevents the RuntimeErrors that were being caught and ignored.
Issue #24455: Prevent IDLE from hanging when a) closing the shell while the
debugger is active (15347); b) closing the debugger with the [X] button
(15348); and c) activating the debugger when already active (24455).
The patch by Mark Roseman does this by making two changes.
1. Suspend and resume the gui.interaction method with the tcl vwait
mechanism intended for this purpose (instead of root.mainloop & .quit).
2. In gui.run, allow any existing interaction to terminate first.
Change 'The program' to 'Your program' in an IDLE 'kill program?' message
to make it clearer that the program referred to is the currently running
user program, not IDLE itself.
Issue #24750: Improve the appearance of the IDLE editor window status bar.
Patch by Mark Roseman.
Issue #25313: Change the handling of new built-in text color themes to better
address the compatibility problem introduced by the addition of IDLE Dark.
Consistently use the revised idleConf.CurrentTheme everywhere in idlelib.
Issue #24782: Extension configuration is now a tab in the IDLE Preferences
dialog rather than a separate dialog. The former tabs are now a sorted
list. Patch by Mark Roseman.
Issue #22726: Re-activate the config dialog help button with some content
about the other buttons and the new IDLE Dark theme.
Issue #24820: IDLE now has an 'IDLE Dark' built-in text color theme.
It is more or less IDLE Classic inverted, with a cobalt blue background.
Strings, comments, keywords, ... are still green, red, orange, ... .
To use it with IDLEs released before November 2015, hit the
'Save as New Custom Theme' button and enter a new name,
such as 'Custom Dark'. The custom theme will work with any IDLE
release, and can be modified.
Issue #25224: README.txt is now an idlelib index for IDLE developers and
curious users. The previous user content is now in the IDLE doc chapter.
'IDLE' now means 'Integrated Development and Learning Environment'.
Issue #24820: Users can now set breakpoint colors in
Settings -> Custom Highlighting. Original patch by Mark Roseman.
Issue #24972: Inactive selection background now matches active selection
background, as configured by users, on all systems. Found items are now
always highlighted on Windows. Initial patch by Mark Roseman.
Issue #24570: Idle: make calltip and completion boxes appear on Macs
affected by a tk regression. Initial patch by Mark Roseman.
Issue #24988: Idle ScrolledList context menus (used in debugger)
now work on Mac Aqua. Patch by Mark Roseman.
Issue #24801: Make right-click for context menu work on Mac Aqua.
Patch by Mark Roseman.
Issue #25173: Associate tkinter messageboxes with a specific widget.
For Mac OSX, make them a 'sheet'. Patch by Mark Roseman.
Issue #25198: Enhance the initial html viewer now used for Idle Help.
Properly indent fixed-pitch text (patch by Mark Roseman).
Give code snippet a very Sphinx-like light blueish-gray background.
Re-use initial width and height set by users for shell and editor.
When the Table of Contents (TOC) menu is used, put the section header
at the top of the screen.
Issue #25225: Condense and rewrite Idle doc section on text colors.
Issue #21995: Explain some differences between IDLE and console Python.
Issue #22820: Explain need for *print* when running file from Idle editor.
Issue #25224: Doc: augment Idle feature list and no-subprocess section.
Issue #25219: Update doc for Idle command line options.
Some were missing and notes were not correct.
Issue #24861: Most of idlelib is private and subject to change.
Use idleib.idle.* to start Idle. See idlelib.__init__.__doc__.
Issue #25199: Idle: add synchronization comments for future maintainers.
Issue #16893: Replace help.txt with help.html for Idle doc display.
The new idlelib/help.html is rstripped Doc/build/html/library/idle.html.
It looks better than help.txt and will better document Idle as released.
The tkinter html viewer that works for this file was written by Mark Roseman.
The now unused EditorWindow.HelpDialog class and helt.txt file are deprecated.
Issue #24199: Deprecate unused idlelib.idlever with possible removal in 3.6.
Issue #24790: Remove extraneous code (which also create 2 & 3 conflicts).
Issue #23672: Allow Idle to edit and run files with astral chars in name.
Patch by Mohd Sanad Zaki Rizvi.
Issue 24745: Idle editor default font. Switch from Courier to
platform-sensitive TkFixedFont. This should not affect current customized
font selections. If there is a problem, edit $HOME/.idlerc/config-main.cfg
and remove 'fontxxx' entries from [Editor Window]. Patch by Mark Roseman.
Issue #21192: Idle editor. When a file is run, put its name in the restart bar.
Do not print false prompts. Original patch by Adnan Umer.
Issue #13884: Idle menus. Remove tearoff lines. Patch by Roger Serwy.
Issue #15809: IDLE shell now uses locale encoding instead of Latin1 for
decoding unicode literals.
Documentation:
Issue #24952: Clarify the default size argument of stack_size() in
the "threading" and "thread" modules. Patch from Mattip.
Issue #20769: Improve reload() docs. Patch by Dorian Pula.
Issue #23589: Remove duplicate sentence from the FAQ. Patch by Yongzhi Pan.
Issue #22155: Add File Handlers subsection with createfilehandler to Tkinter
doc. Remove obsolete example from FAQ. Patch by Martin Panter.
Tests:
Issue #24751: When running regrtest with the ``-w`` command line option,
a test run is no longer marked as a failure if all tests succeed when
re-run.
PCbuild\rt.bat now accepts an unlimited number of arguments to pass along
to regrtest.py. Previously there was a limit of 9.
Build:
Issue #24915: When doing a PGO build, the test suite is now used instead of
pybench; Clang support was also added as part off this work. Initial patch by
Alecsandru Patrascu of Intel.
Issue #24986: It is now possible to build Python on Windows without errors
when external libraries are not available.
Issue #24508: Backported the MSBuild project files from Python 3.5. The
backported files replace the old project files in PCbuild; the old files moved
to PC/VS9.0 and remain supported.
Issue #24603: Update Windows builds and OS X 10.5 installer to use OpenSSL
1.0.2d.
Windows:
Issue #25022: Removed very outdated PC/example_nt/ directory.

New in Python 2.7.11 RC1 (Dec 1, 2015)

Core and Builtins:
Issue #25678: Avoid buffer overreads when int(), long(), float(), and
compile() are passed buffer objects. These objects are not necessarily
terminated by a null byte, but the functions assumed they were.
Issue #25388: Fixed tokenizer hang when processing undecodable source code
with a null byte.
Issue #22995: Default implementation of __reduce__ and __reduce_ex__ now
rejects builtin types with not defined __new__.
Issue #7267: format(int, 'c') now raises OverflowError when the argument is
not in range(0, 256).
Issue #24806: Prevent builtin types that are not allowed to be subclassed from
being subclassed through multiple inheritance.
Issue #24848: Fixed a number of bugs in UTF-7 decoding of misformed data.
Issue #25003: os.urandom() doesn't use getentropy() on Solaris because
getentropy() is blocking, whereas os.urandom() should not block. getentropy()
is supported since Solaris 11.3.
Issue #21167: NAN operations are now handled correctly when python is
compiled with ICC even if -fp-model strict is not specified.
Issue #24467: Fixed possible buffer over-read in bytearray. The bytearray
object now always allocates place for trailing null byte and it's buffer now
is always null-terminated.
Issue #19543: encode() and decode() methods and constructors of str,
unicode and bytearray classes now emit deprecation warning for known
non-text encodings when Python is ran with the -3 option.
Issue #24115: Update uses of PyObject_IsTrue(), PyObject_Not(),
PyObject_IsInstance(), PyObject_RichCompareBool() and _PyDict_Contains()
to check for and handle errors correctly.
Issue #4753: On compilers where it is supported, use "computed gotos" for
bytecode dispatch in the interpreter. This improves interpretation
performance.
Issue #22939: Fixed integer overflow in iterator object. Original patch by
Clement Rouault.
Issue #24102: Fixed exception type checking in standard error handlers.
Library:
Issue #10128: backport issue #10845's mitigation of incompatibilities between
the multiprocessing module and directory and zipfile execution.
Multiprocessing on Windows will now automatically skip rerunning __main__ in
spawned processes, rather than failing with AssertionError.
Issue #25578: Fix (another) memory leak in SSLSocket.getpeercer().
Issue #25590: In the Readline completer, only call getattr() once per
attribute.
Issue #25530: Disable the vulnerable SSLv3 protocol by default when creating
ssl.SSLContext.
Issue #25569: Fix memory leak in SSLSocket.getpeercert().
Issue #7759: Fixed the mhlib module on filesystems that doesn't support
link counting for directories.
Issue #892902: Fixed pickling recursive objects.
Issue #18010: Fix the pydoc GUI's search function to handle exceptions
from importing packages.
Issue #25515: Always use os.urandom as a source of randomness in uuid.uuid4.
Issue #21827: Fixed textwrap.dedent() for the case when largest common
whitespace is a substring of smallest leading whitespace.
Based on patch by Robert Li.
Issue #21709: Fix the logging module to not depend upon __file__ being set
properly to get the filename of its caller from the stack. This allows it
to work if run in a frozen or embedded environment where the module's
.__file__ attribute does not match its code object's .co_filename.
Issue #25319: When threading.Event is reinitialized, the underlying condition
should use a regular lock rather than a recursive lock.
Issue #25232: Fix CGIRequestHandler to split the query from the URL at the
first question mark (?) rather than the last. Patch from Xiang Zhang.
Issue #24657: Prevent CGIRequestHandler from collapsing slashes in the
query part of the URL as if it were a path. Patch from Xiang Zhang.
Issue #22958: Constructor and update method of weakref.WeakValueDictionary
now accept the self keyword argument.
Issue #22609: Constructor and the update method of collections.UserDict now
accept the self keyword argument.
Issue #25203: Failed readline.set_completer_delims() no longer left the
module in inconsistent state.
Issue #19143: platform module now reads Windows version from kernel32.dll to
avoid compatibility shims.
Issue #25135: Make deque_clear() safer by emptying the deque before clearing.
This helps avoid possible reentrancy issues.
Issue #24684: socket.socket.getaddrinfo() now calls
PyUnicode_AsEncodedString() instead of calling the encode() method of the
host, to handle correctly custom unicode string with an encode() method
which doesn't return a byte string. The encoder of the IDNA codec is now
called directly instead of calling the encode() method of the string.
Issue #24982: shutil.make_archive() with the "zip" format now adds entries
for directories (including empty directories) in ZIP file.
Issue #17849: Raise a sensible exception if an invalid response is
received for a HTTP tunnel request, as seen with some servers that
do not support tunnelling. Initial patch from Cory Benfield.
Issue #16180: Exit pdb if file has syntax error, instead of trapping user
in an infinite loop. Patch by Xavier de Gaye.
Issue #22812: Fix unittest discovery examples.
Patch from Pam McA'Nulty.
Issue #24634: Importing uuid should not try to load libc on Windows
Issue #23652: Make it possible to compile the select module against the
libc headers from the Linux Standard Base, which do not include some
EPOLL macros. Initial patch by Matt Frank.
Issue #15138: Speed up base64.urlsafe_b64{en,de}code considerably.
Issue #23319: Fix ctypes.BigEndianStructure, swap correctly bytes. Patch
written by Matthieu Gautier.
Issue #23254: Document how to close the TCPServer listening socket.
Patch from Martin Panter.
Issue #17527: Add PATCH to wsgiref.validator. Patch from Luca Sbardella.
Issue #24613: Calling array.fromstring() with self is no longer allowed
to prevent the use-after-free error. Patch by John Leitch.
Issue #24708: Fix possible integer overflow in strop.replace().
Issue #24620: Random.setstate() now validates the value of state last element.
Issue #13938: 2to3 converts StringTypes to a tuple. Patch from Mark Hammond.
Issue #24611: Fixed compiling the posix module on non-Windows platforms
without mknod() or makedev() (e.g. on Unixware).
Issue #18684: Fixed reading out of the buffer in the re module.
Issue #24259: tarfile now raises a ReadError if an archive is truncated
inside a data segment.
Issue #24514: tarfile now tolerates number fields consisting of only
whitespace.
Issue #20387: Restore semantic round-trip correctness in tokenize/untokenize
for tab-indented blocks.
Issue #24456: Fixed possible buffer over-read in adpcm2lin() and lin2adpcm()
functions of the audioop module. Fixed SystemError when the state is not a
tuple. Fixed possible memory leak.
Issue #24481: Fix possible memory corruption with large profiler info strings
in hotshot.
Issue #24489: ensure a previously set C errno doesn't disturb cmath.polar().
Issue #19543: io.TextIOWrapper (and hence io.open()) now uses the internal
codec marking system added to emit deprecation warning for known non-text
encodings at stream construction time when Python is ran with the -3 option.
Issue #24264: Fixed buffer overflow in the imageop module.
Issue #5633: Fixed timeit when the statement is a string and the setup is not.
Issue #24326: Fixed audioop.ratecv() with non-default weightB argument.
Original patch by David Moore.
Issue #22095: Fixed HTTPConnection.set_tunnel with default port. The port
value in the host header was set to "None". Patch by Demian Brecht.
Issue #24257: Fixed segmentation fault in sqlite3.Row constructor with faked
cursor type.
Issue #24286: Dict view were not registered with the MappingView abstract
base classes. This caused key and item views in OrderedDict to not be equal
to their regular dict counterparts.
Issue #22107: tempfile.gettempdir() and tempfile.mkdtemp() now try again
when a directory with the chosen name already exists on Windows as well as
on Unix. tempfile.mkstemp() now fails early if parent directory is not
valid (not exists or is a file) on Windows.
Issue #6598: Increased time precision and random number range in
email.utils.make_msgid() to strengthen the uniqueness of the message ID.
Issue #24091: Fixed various crashes in corner cases in cElementTree.
Issue #15267: HTTPConnection.request() now is compatibile with old-style
classes (such as TemporaryFile). Original patch by Atsuo Ishimoto.
Issue #20014: array.array() now accepts unicode typecodes. Based on patch by
Vajrasky Kok.
Issue #23637: Showing a warning no longer fails with UnicodeErrror.
Formatting unicode warning in the file with the path containing non-ascii
characters no longer fails with UnicodeErrror.
Issue #24134: Reverted issue #24134 changes.
IDLE:
Issue 15348: Stop the debugger engine (normally in a user process)
before closing the debugger window (running in the IDLE process).
This prevents the RuntimeErrors that were being caught and ignored.
Issue #24455: Prevent IDLE from hanging when a) closing the shell while the
debugger is active (15347); b) closing the debugger with the [X] button
(15348); and c) activating the debugger when already active (24455).
The patch by Mark Roseman does this by making two changes.
1. Suspend and resume the gui.interaction method with the tcl vwait
mechanism intended for this purpose (instead of root.mainloop & .quit).
2. In gui.run, allow any existing interaction to terminate first.
Change 'The program' to 'Your program' in an IDLE 'kill program?' message
to make it clearer that the program referred to is the currently running
user program, not IDLE itself.
Issue #24750: Improve the appearance of the IDLE editor window status bar.
Patch by Mark Roseman.
Issue #25313: Change the handling of new built-in text color themes to better
address the compatibility problem introduced by the addition of IDLE Dark.
Consistently use the revised idleConf.CurrentTheme everywhere in idlelib.
Issue #24782: Extension configuration is now a tab in the IDLE Preferences
dialog rather than a separate dialog. The former tabs are now a sorted
list. Patch by Mark Roseman.
Issue #22726: Re-activate the config dialog help button with some content
about the other buttons and the new IDLE Dark theme.
Issue #24820: IDLE now has an 'IDLE Dark' built-in text color theme.
It is more or less IDLE Classic inverted, with a cobalt blue background.
Strings, comments, keywords, ... are still green, red, orange, ... .
To use it with IDLEs released before November 2015, hit the
'Save as New Custom Theme' button and enter a new name,
such as 'Custom Dark'. The custom theme will work with any IDLE
release, and can be modified.
Issue #25224: README.txt is now an idlelib index for IDLE developers and
curious users. The previous user content is now in the IDLE doc chapter.
'IDLE' now means 'Integrated Development and Learning Environment'.
Issue #24820: Users can now set breakpoint colors in
Settings -> Custom Highlighting. Original patch by Mark Roseman.
Issue #24972: Inactive selection background now matches active selection
background, as configured by users, on all systems. Found items are now
always highlighted on Windows. Initial patch by Mark Roseman.
Issue #24570: Idle: make calltip and completion boxes appear on Macs
affected by a tk regression. Initial patch by Mark Roseman.
Issue #24988: Idle ScrolledList context menus (used in debugger)
now work on Mac Aqua. Patch by Mark Roseman.
Issue #24801: Make right-click for context menu work on Mac Aqua.
Patch by Mark Roseman.
Issue #25173: Associate tkinter messageboxes with a specific widget.
For Mac OSX, make them a 'sheet'. Patch by Mark Roseman.
Issue #25198: Enhance the initial html viewer now used for Idle Help.
Properly indent fixed-pitch text (patch by Mark Roseman).
Give code snippet a very Sphinx-like light blueish-gray background.
Re-use initial width and height set by users for shell and editor.
When the Table of Contents (TOC) menu is used, put the section header
at the top of the screen.
Issue #25225: Condense and rewrite Idle doc section on text colors.
Issue #21995: Explain some differences between IDLE and console Python.
Issue #22820: Explain need for *print* when running file from Idle editor.
Issue #25224: Doc: augment Idle feature list and no-subprocess section.
Issue #25219: Update doc for Idle command line options.
Some were missing and notes were not correct.
Issue #24861: Most of idlelib is private and subject to change.
Use idleib.idle.* to start Idle. See idlelib.__init__.__doc__.
Issue #25199: Idle: add synchronization comments for future maintainers.
Issue #16893: Replace help.txt with help.html for Idle doc display.
The new idlelib/help.html is rstripped Doc/build/html/library/idle.html.
It looks better than help.txt and will better document Idle as released.
The tkinter html viewer that works for this file was written by Mark Roseman.
The now unused EditorWindow.HelpDialog class and helt.txt file are deprecated.
Issue #24199: Deprecate unused idlelib.idlever with possible removal in 3.6.
Issue #24790: Remove extraneous code (which also create 2 & 3 conflicts).
Issue #23672: Allow Idle to edit and run files with astral chars in name.
Patch by Mohd Sanad Zaki Rizvi.
Issue 24745: Idle editor default font. Switch from Courier to
platform-sensitive TkFixedFont. This should not affect current customized
font selections. If there is a problem, edit $HOME/.idlerc/config-main.cfg
and remove 'fontxxx' entries from [Editor Window]. Patch by Mark Roseman.
Issue #21192: Idle editor. When a file is run, put its name in the restart bar.
Do not print false prompts. Original patch by Adnan Umer.
Issue #13884: Idle menus. Remove tearoff lines. Patch by Roger Serwy.
Issue #15809: IDLE shell now uses locale encoding instead of Latin1 for
decoding unicode literals.
Documentation:
Issue #24952: Clarify the default size argument of stack_size() in
the "threading" and "thread" modules. Patch from Mattip.
Issue #20769: Improve reload() docs. Patch by Dorian Pula.
Issue #23589: Remove duplicate sentence from the FAQ. Patch by Yongzhi Pan.
Issue #22155: Add File Handlers subsection with createfilehandler to Tkinter
doc. Remove obsolete example from FAQ. Patch by Martin Panter.
Tests:
Issue #24751: When running regrtest with the ``-w`` command line option,
a test run is no longer marked as a failure if all tests succeed when
re-run.
PCbuild\rt.bat now accepts an unlimited number of arguments to pass along
to regrtest.py. Previously there was a limit of 9.
Build:
Issue #24915: When doing a PGO build, the test suite is now used instead of
pybench; Clang support was also added as part off this work. Initial patch by
Alecsandru Patrascu of Intel.
Issue #24986: It is now possible to build Python on Windows without errors
when external libraries are not available.
Issue #24508: Backported the MSBuild project files from Python 3.5. The
backported files replace the old project files in PCbuild; the old files moved
to PC/VS9.0 and remain supported.
Issue #24603: Update Windows builds and OS X 10.5 installer to use OpenSSL
1.0.2d.
Windows:
Issue #25022: Removed very outdated PC/example_nt/ directory.

New in Python 3.5.0 (Sep 14, 2015)

New in Python 3.5.0 RC 4 (Sep 10, 2015)

New in Python 3.5.0 RC 3 (Sep 8, 2015)

New in Python 3.5.0 RC 2 (Aug 25, 2015)

New in Python 3.5.0 RC (Aug 11, 2015)

Core and Builtins:
Issue #24667: Resize odict in all cases that the underlying dict resizes.
Library:
Issue #24824: Signatures of codecs.encode() and codecs.decode() now are compatible with pydoc.
Issue #24634: Importing uuid should not try to load libc on Windows
Issue #24798: _msvccompiler.py doesn’t properly support manifests
Issue #4395: Better testing and documentation of binary operators. Patch by Martin Panter.
Issue #23973: Update typing.py from GitHub repo.
Issue #23004: mock_open() now reads binary data correctly when the type of read_data is bytes. Initial patch by Aaron Hill.
Issue #23888: Handle fractional time in cookie expiry. Patch by ssh.
Issue #23652: Make it possible to compile the select module against the libc headers from the Linux Standard Base, which do not include some EPOLL macros. Patch by Matt Frank.
Issue #22932: Fix timezones in email.utils.formatdate. Patch from Dmitry Shachnev.
Issue #23779: imaplib raises TypeError if authenticator tries to abort. Patch from Craig Holmquist.
Issue #23319: Fix ctypes.BigEndianStructure, swap correctly bytes. Patch written by Matthieu Gautier.
Issue #23254: Document how to close the TCPServer listening socket. Patch from Martin Panter.
Issue #19450: Update Windows and OS X installer builds to use SQLite 3.8.11.
Issue #17527: Add PATCH to wsgiref.validator. Patch from Luca Sbardella.
Issue #23812: Fix asyncio.Queue.get() to avoid loosing items on cancellation. Patch by Gustavo J. A. M. Carneiro.
Issue #24791: Fix grammar regression for call syntax: ‘g(*a or b)’.
Documentation:
Issue #24129: Clarify the reference documentation for name resolution. This includes removing the assumption that readers will be familiar with the name resolution scheme Python used prior to the introduction of lexical scoping for function namespaces. Patch by Ivan Levkivskyi.
Issue #20769: Improve reload() docs. Patch by Dorian Pula.
Issue #23589: Remove duplicate sentence from the FAQ. Patch by Yongzhi Pan.
Issue #24729: Correct IO tutorial to match implementation regarding encoding parameter to open function.
Tests:
Issue #24751: When running regrtest with the -w command line option, a test run is no longer marked as a failure if all tests succeed when re-run.

New in Python 2.7.10 (Jul 6, 2015)

New in Python 3.5.0 Beta 2 (Jun 1, 2015)

New in Python 3.5.0 Alpha 4 (Apr 20, 2015)

Core and Builtins:
Issue #22980: Under Linux, GNU/KFreeBSD and the Hurd, C extensions now include the architecture triplet in the extension name, to make it easy to test builds for different ABIs in the same working tree. Under OS X, the extension name now includes PEP 3149-style information.
Issue #22631: Added Linux-specific socket constant CAN_RAW_FD_FRAMES. Patch courtesy of Joe Jevnik.
Issue #23731: Implement PEP 488: removal of .pyo files.
Issue #23726: Don’t enable GC for user subclasses of non-GC types that don’t add any new fields. Patch by Eugene Toder.
Issue #23309: Avoid a deadlock at shutdown if a daemon thread is aborted while it is holding a lock to a buffered I/O object, and the main thread tries to use the same I/O object (typically stdout or stderr). A fatal error is emitted instead.
Issue #22977: Fixed formatting Windows error messages on Wine. Patch by Martin Panter.
Issue #23466: %c, %o, %x, and %X in bytes formatting now raise TypeError on non-integer input.
Library:
Issue #16914: new debuglevel 2 in smtplib adds timestamps to debug output.
Issue #7159: urllib.request now supports sending auth credentials automatically after the first 401. This enhancement is a superset of the enhancement from issue #19494 and supersedes that change.
Issue #23703: Fix a regression in urljoin() introduced in 901e4e52b20a. Patch by Demian Brecht.
Issue #4254: Adds _curses.update_lines_cols() Patch by Arnon Yaari
Issue 19933: Provide default argument for ndigits in round. Patch by Vajrasky Kok.
Issue #23193: Add a numeric_owner parameter to tarfile.TarFile.extract and tarfile.TarFile.extractall. Patch by Michael Vogt and Eric Smith.
Issue #23342: Add a subprocess.run() function than returns a CalledProcess instance for a more consistent API than the existing call* functions.
Issue #21217: inspect.getsourcelines() now tries to compute the start and end lines from the code object, fixing an issue when a lambda function is used as decorator argument. Patch by Thomas Ballinger and Allison Kaptur.
Issue #23811: Add missing newline to the PyCompileError error message. Patch by Alex Shkop.
Issue #21116: Avoid blowing memory when allocating a multiprocessing shared array that’s larger than 50% of the available RAM. Patch by Médéric Boquien.
Issue #22982: Improve BOM handling when seeking to multiple positions of a writable text file.
Issue #23464: Removed deprecated asyncio JoinableQueue.
Issue #23529: Limit the size of decompressed data when reading from GzipFile, BZ2File or LZMAFile. This defeats denial of service attacks using compressed bombs (i.e. compressed payloads which decompress to a huge size). Patch by Martin Panter and Nikolaus Rath.
Issue #21859: Added Python implementation of io.FileIO.
Issue #23865: close() methods in multiple modules now are idempotent and more robust at shutdown. If they need to release multiple resources, all are released even if errors occur.
Issue #23400: Raise same exception on both Python 2 and 3 if sem_open is not available. Patch by Davin Potts.
Issue #10838: The subprocess now module includes SubprocessError and TimeoutError in its list of exported names for the users wild enough to use from subprocess import *.
Issue #23411: Added DefragResult, ParseResult, SplitResult, DefragResultBytes, ParseResultBytes, and SplitResultBytes to urllib.parse.__all__. Patch by Martin Panter.
Issue #23881: urllib.request.ftpwrapper constructor now closes the socket if the FTP connection failed to fix a ResourceWarning.
Issue #23853: socket.socket.sendall() does no more reset the socket timeout each time data is sent successfuly. The socket timeout is now the maximum total duration to send all data.
Issue #22721: An order of multiline pprint output of set or dict containing orderable and non-orderable elements no longer depends on iteration order of set or dict.
Issue #15133: _tkinter.tkapp.getboolean() now supports Tcl_Obj and always returns bool. tkinter.BooleanVar now validates input values (accepted bool, int, str, and Tcl_Obj). tkinter.BooleanVar.get() now always returns bool.
Issue #10590: xml.sax.parseString() now supports string argument.
Issue #23338: Fixed formatting ctypes error messages on Cygwin. Patch by Makoto Kato.
Issue #15582: inspect.getdoc() now follows inheritance chains.
Issue #2175: SAX parsers now support a character stream of InputSource object.
Issue #16840: Tkinter now supports 64-bit integers added in Tcl 8.4 and arbitrary precision integers added in Tcl 8.5.
Issue #23834: Fix socket.sendto(), use the C Py_ssize_t type to store the result of sendto() instead of the C int type.
Issue #23618: socket.socket.connect() now waits until the connection completes instead of raising InterruptedError if the connection is interrupted by signals, signal handlers don’t raise an exception and the socket is blocking or has a timeout. socket.socket.connect() still raise InterruptedError for non-blocking sockets.
Issue #21526: Tkinter now supports new boolean type in Tcl 8.5.
Issue #23836: Fix the faulthandler module to handle reentrant calls to its signal handlers.
Issue #23838: linecache now clears the cache and returns an empty result on MemoryError.
Issue #10395: Added os.path.commonpath(). Implemented in posixpath and ntpath. Based on patch by Rafik Draoui.
Issue #23611: Serializing more “lookupable” objects (such as unbound methods or nested classes) now are supported with pickle protocols < 4.
Issue #13583: sqlite3.Row now supports slice indexing.
Issue #18473: Fixed 2to3 and 3to2 compatible pickle mappings. Fixed ambigious reverse mappings. Added many new mappings. Import mapping is no longer applied to modules already mapped with full name mapping.
Issue #23485: select.select() is now retried automatically with the recomputed timeout when interrupted by a signal, except if the signal handler raises an exception. This change is part of the PEP 475.
Issue #23752: When built from an existing file descriptor, io.FileIO() now only calls fstat() once. Before fstat() was called twice, which was not necessary.
Issue #23704: collections.deque() objects now support __add__, __mul__, and __imul__().
Issue #23171: csv.Writer.writerow() now supports arbitrary iterables.
Issue #23745: The new email header parser now handles duplicate MIME parameter names without error, similar to how get_param behaves.
Issue #22117: Fix os.utime(), it now rounds the timestamp towards minus infinity (-inf) instead of rounding towards zero.
Issue #23310: Fix MagicMock’s initializer to work with __methods__, just like configure_mock(). Patch by Kasia Jachim.
Build:
Issue #23817: FreeBSD now uses “1.0” the the SOVERSION as other operating systems, instead of just “1”.
Issue #23501: Argument Clinic now generates code into separate files by default.
Tests:
Issue #23799: Added test.support.start_threads() for running and cleaning up multiple threads.
Issue #22390: test.regrtest now emits a warning if temporary files or directories are left after running a test.
Tools/Demos:
Issue #18128: pygettext now uses standard +NNNN format in the POT-Creation-Date header.
Issue #23935: Argument Clinic’s understanding of format units accepting bytes, bytearrays, and buffers is now consistent with both the documentation and the implementation.
Issue #23944: Argument Clinic now wraps long impl prototypes at column 78.
Issue #20586: Argument Clinic now ensures that functions without docstrings have signatures.
Issue #23492: Argument Clinic now generates argument parsing code with PyArg_Parse instead of PyArg_ParseTuple if possible.
Issue #23500: Argument Clinic is now smarter about generating the “#ifndef” (empty) definition of the methoddef macro: it’s only generated once, even if Argument Clinic processes the same symbol multiple times, and it’s emitted at the end of all processing rather than immediately after the first use.
C API:
Issue #23998: PyImport_ReInitLock() now checks for lock allocation error

New in Python 3.5.0 Alpha 3 (Mar 30, 2015)

Core and Builtins:
Issue #23466: %c, %o, %x, and %X in bytes formatting now raise TypeError on non-integer input.
Issue #23573: Increased performance of string search operations (str.find, str.index, str.count, the in operator, str.split, str.partition) with arguments of different kinds (UCS1, UCS2, UCS4).
Issue #23753: Python doesn’t support anymore platforms without stat() or fstat(), these functions are always required.
Issue #23681: The -b option now affects comparisons of bytes with int.
Issue #23632: Memoryviews now allow tuple indexing (including for multi-dimensional memoryviews).
Issue #23192: Fixed generator lambdas. Patch by Bruno Cauet.
Issue #23629: Fix the default __sizeof__ implementation for variable-sized objects.
Library:
Issue #23171: csv.Writer.writerow() now supports arbitrary iterables.
Issue #23745: The new email header parser now handles duplicate MIME parameter names without error, similar to how get_param behaves.
Issue #22117: Fix os.utime(), it now rounds the timestamp towards minus infinity (-inf) instead of rounding towards zero.
Issue #14260: The groupindex attribute of regular expression pattern object now is non-modifiable mapping.
Issue #23792: Ignore KeyboardInterrupt when the pydoc pager is active. This mimics the behavior of the standard unix pagers, and prevents pipepager from shutting down while the pager itself is still running.
Issue #23775: pprint() of OrderedDict now outputs the same representation as repr().
Issue #23765: Removed IsBadStringPtr calls in ctypes
Issue #22364: Improved some re error messages using regex for hints.
Issue #23742: ntpath.expandvars() no longer loses unbalanced single quotes.
Issue #21717: The zipfile.ZipFile.open function now supports ‘x’ (exclusive creation) mode.
Issue #21802: The reader in BufferedRWPair now is closed even when closing writer failed in BufferedRWPair.close().
Issue #23622: Unknown escapes in regular expressions that consist of '\' and ASCII letter now raise a deprecation warning and will be forbidden in Python 3.6.
Issue #23671: string.Template now allows to specify the “self” parameter as keyword argument. string.Formatter now allows to specify the “self” and the “format_string” parameters as keyword arguments.
Issue #23502: The pprint module now supports mapping proxies.
Issue #17530: pprint now wraps long bytes objects and bytearrays.
Issue #22687: Fixed some corner cases in breaking words in tetxtwrap. Got rid of quadratic complexity in breaking long words.
Issue #4727: The copy module now uses pickle protocol 4 (PEP 3154) and supports copying of instances of classes whose __new__ method takes keyword-only arguments.
Issue #23491: Added a zipapp module to support creating executable zip file archives of Python code. Registered ”.pyz” and ”.pyzw” extensions on Windows for these archives (PEP 441).
Issue #23657: Avoid explicit checks for str in zipapp, adding support for pathlib.Path objects as arguments.
Issue #23688: Added support of arbitrary bytes-like objects and avoided unnecessary copying of memoryview in gzip.GzipFile.write(). Original patch by Wolfgang Maier.
Issue #23252: Added support for writing ZIP files to unseekable streams.
Issue #21526: Tkinter now supports new boolean type in Tcl 8.5.
Issue #23647: Increase impalib’s MAXLINE to accommodate modern mailbox sizes.
Issue #23539: If body is None, http.client.HTTPConnection.request now sets Content-Length to 0 for PUT, POST, and PATCH headers to avoid 411 errors from some web servers.
Issue #22351: The nntplib.NNTP constructor no longer leaves the connection and socket open until the garbage collector cleans them up. Patch by Martin Panter.
Issue #23704: collections.deque() objects now support methods for index(), insert(), and copy(). This allows deques to be registered as a MutableSequence and it improves their substitutablity for lists.
Issue #23715: signal.sigwaitinfo() and signal.sigtimedwait() are now retried when interrupted by a signal not in the sigset parameter, if the signal handler does not raise an exception. signal.sigtimedwait() recomputes the timeout with a monotonic clock when it is retried.
Issue #23001: Few functions in modules mmap, ossaudiodev, socket, ssl, and codecs, that accepted only read-only bytes-like object now accept writable bytes-like object too.
Issue #23646: If time.sleep() is interrupted by a signal, the sleep is now retried with the recomputed delay, except if the signal handler raises an exception (PEP 475).
Issue #23136: _strptime now uniformly handles all days in week 0, including Dec 30 of previous year. Based on patch by Jim Carroll.
Issue #23700: Iterator of NamedTemporaryFile now keeps a reference to NamedTemporaryFile instance. Patch by Bohuslav Kabrda.
Issue #22903: The fake test case created by unittest.loader when it fails importing a test module is now picklable.
Issue #22181: On Linux, os.urandom() now uses the new getrandom() syscall if available, syscall introduced in the Linux kernel 3.17. It is more reliable and more secure, because it avoids the need of a file descriptor and waits until the kernel has enough entropy.
Issue #2211: Updated the implementation of the http.cookies.Morsel class. Setting attributes key, value and coded_value directly now is deprecated. update() and setdefault() now transform and check keys. Comparing for equality now takes into account attributes key, value and coded_value. copy() now returns a Morsel, not a dict. repr() now contains all attributes. Optimized checking keys and quoting values. Added new tests. Original patch by Demian Brecht.
Issue #18983: Allow selection of output units in timeit. Patch by Julian Gindi.
Issue #23631: Fix traceback.format_list when a traceback has been mutated.
Issue #23568: Add rdivmod support to MagicMock() objects. Patch by Håkan Lövdahl.
Issue #2052: Add charset parameter to HtmlDiff.make_file().
Issue #23138: Fixed parsing cookies with absent keys or values in cookiejar. Patch by Demian Brecht.
Issue #23051: multiprocessing.Pool methods imap() and imap_unordered() now handle exceptions raised by an iterator. Patch by Alon Diamant and Davin Potts.
Issue #23581: Add matmul support to MagicMock. Patch by Håkan Lövdahl.
Issue #23566: enable(), register(), dump_traceback() and dump_traceback_later() functions of faulthandler now accept file descriptors. Patch by Wei Wu.
Issue #22928: Disabled HTTP header injections in http.client. Original patch by Demian Brecht.
Issue #23615: Modules bz2, tarfile and tokenize now can be reloaded with imp.reload(). Patch by Thomas Kluyver.
Issue #23605: os.walk() now calls os.scandir() instead of os.listdir(). The usage of os.scandir() reduces the number of calls to os.stat(). Initial patch written by Ben Hoyt.
Build:
Issue #23585: make patchcheck will ensure the interpreter is built.
Tests:
Issue #22390: test.regrtest now emits a warning if temporary files or directories are left after running a test.
Issue #23583: Added tests for standard IO streams in IDLE.
Issue #22289: Prevent test_urllib2net failures due to ftp connection timeout.

New in Python 3.5.0 Alpha 2 (Mar 9, 2015)

Core and Builtins:
Issue #22980: Under Linux, C extensions now include bitness in the file name, to make it easy to test 32-bit and 64-bit builds in the same working tree.
Issue #23571: PyObject_Call() and PyCFunction_Call() now raise a SystemError if a function returns a result and raises an exception. The SystemError is chained to the previous exception.
Library:
Issue #22524: New os.scandir() function, part of the PEP 471: “os.scandir() function – a better and faster directory iterator”. Patch written by Ben Hoyt.
Issue #23103: Reduced the memory consumption of IPv4Address and IPv6Address.
Issue #21793: BaseHTTPRequestHandler again logs response code as numeric, not as stringified enum. Patch by Demian Brecht.
Issue #23476: In the ssl module, enable OpenSSL’s X509_V_FLAG_TRUSTED_FIRST flag on certificate stores when it is available.
Issue #23576: Avoid stalling in SSL reads when EOF has been reached in the SSL layer but the underlying connection hasn’t been closed.
Issue #23504: Added an __all__ to the types module.
Issue #23563: Optimized utility functions in urllib.parse.
Issue #7830: Flatten nested functools.partial.
Issue #20204: Added the __module__ attribute to _tkinter classes.
Issue #19980: Improved help() for non-recognized strings. help(‘’) now shows the help on str. help(‘help’) now shows the help on help(). Original patch by Mark Lawrence.
Issue #23521: Corrected pure python implementation of timedelta division.
Eliminated OverflowError from timedelta * float for some floats;
Corrected rounding in timedlta true division.
Issue #21619: Popen objects no longer leave a zombie after exit in the with statement if the pipe was broken. Patch by Martin Panter.
Issue #22936: Make it possible to show local variables in tracebacks for both the traceback module and unittest.
Issue #15955: Add an option to limit the output size in bz2.decompress(). Patch by Nikolaus Rath.
Issue #6639: Module-level turtle functions no longer raise TclError after closing the window.
Issues #814253, #9179: Group references and conditional group references now work in lookbehind assertions in regular expressions.
Issue #23215: Multibyte codecs with custom error handlers that ignores errors consumed too much memory and raised SystemError or MemoryError. Original patch by Aleksi Torhamo.
Issue #5700: io.FileIO() called flush() after closing the file. flush() was not called in close() if closefd=False.
Issue #23374: Fixed pydoc failure with non-ASCII files when stdout encoding differs from file system encoding (e.g. on Mac OS).
Issue #23481: Remove RC4 from the SSL module’s default cipher list.
Issue #21548: Fix pydoc.synopsis() and pydoc.apropos() on modules with empty docstrings.
Issue #22885: Fixed arbitrary code execution vulnerability in the dbm.dumb module. Original patch by Claudiu Popa.
Issue #23239: ssl.match_hostname() now supports matching of IP addresses.
Issue #23146: Fix mishandling of absolute Windows paths with forward slashes in pathlib.
Issue #23096: Pickle representation of floats with protocol 0 now is the same for both Python and C implementations.
Issue #19105: pprint now more efficiently uses free space at the right.
Issue #14910: Add allow_abbrev parameter to argparse.ArgumentParser. Patch by Jonathan Paugh, Steven Bethard, paul j3 and Daniel Eriksson.
Issue #21717: tarfile.open() now supports ‘x’ (exclusive creation) mode.
Issue #23344: marshal.dumps() is now 20-25% faster on average.
Issue #20416: marshal.dumps() with protocols 3 and 4 is now 40-50% faster on average.
Issue #23421: Fixed compression in tarfile CLI. Patch by wdv4758h.
Issue #23367: Fix possible overflows in the unicodedata module.
Issue #23361: Fix possible overflow in Windows subprocess creation code.
logging.handlers.QueueListener now takes a respect_handler_level keyword argument which, if set to True, will pass messages to handlers taking handler levels into account.
Issue #19705: turtledemo now has a visual sorting algorithm demo. Original patch from Jason Yeo.
Build:
Issue #23445: pydebug builds now use “gcc -Og” where possible, to make the resulting executable faster.
C API:
Issue #20204: Deprecation warning is now raised for builtin type without the __module__ attribute.
Windows:
Issue #23465: Implement PEP 486 - Make the Python Launcher aware of virtual environments. Patch by Paul Moore.
Issue #23437: Make user scripts directory versioned on Windows. Patch by Paul Moore.

New in Python 3.4.3 (Feb 25, 2015)

New in Python 3.5.0 Alpha 1 (Feb 9, 2015)

Core and Builtins:
Issue #23285: PEP 475 - EINTR handling.
Issue #22735: Fix many edge cases (including crashes) involving custom mro() implementations.
Issue #22896: Avoid using PyObject_AsCharBuffer(), PyObject_AsReadBuffer() and PyObject_AsWriteBuffer().
Issue #21295: Revert some changes (issue #16795) to AST line numbers and column offsets that constituted a regression.
Issue #22986: Allow changing an object’s __class__ between a dynamic type and static type in some cases.
Issue #15859: PyUnicode_EncodeFSDefault(), PyUnicode_EncodeMBCS() and PyUnicode_EncodeCodePage() now raise an exception if the object is not an Unicode object. For PyUnicode_EncodeFSDefault(), it was already the case on platforms other than Windows. Patch written by Campbell Barton.
Issue #21408: The default __ne__() now returns NotImplemented if __eq__() returned NotImplemented. Original patch by Martin Panter.
Issue #23321: Fixed a crash in str.decode() when error handler returned replacment string longer than mailformed input data.
Issue #22286: The “backslashreplace” error handlers now works with decoding and translating.
Issue #23253: Delay-load ShellExecute[AW] in os.startfile for reduced startup overhead on Windows.
Issue #22038: pyatomic.h now uses stdatomic.h or GCC built-in functions for atomic memory access if available. Patch written by Vitor de Lima and Gustavo Temple.
Issue #20284: %-interpolation (aka printf) formatting added for bytes and bytearray.
Issue #23048: Fix jumping out of an infinite while loop in the pdb.
Issue #20335: bytes constructor now raises TypeError when encoding or errors is specified with non-string argument. Based on patch by Renaud Blanch.
Issue #22834: If the current working directory ends up being set to a non-existent directory then import will no longer raise FileNotFoundError.
Issue #22869: Move the interpreter startup & shutdown code to a new dedicated pylifecycle.c module
Issue #22847: Improve method cache efficiency.
Issue #22335: Fix crash when trying to enlarge a bytearray to 0x7fffffff bytes on a 32-bit platform.
Issue #22653: Fix an assertion failure in debug mode when doing a reentrant dict insertion in debug mode.
Issue #22643: Fix integer overflow in Unicode case operations (upper, lower, title, swapcase, casefold).
Issue #17636: Circular imports involving relative imports are now supported.
Issue #22604: Fix assertion error in debug mode when dividing a complex number by (nan+0j).
Issue #21052: Do not raise ImportWarning when sys.path_hooks or sys.meta_path are set to None.
Issue #16518: Use ‘bytes-like object required’ in error messages that previously used the far more cryptic “‘x’ does not support the buffer protocol.
Issue #22470: Fixed integer overflow issues in “backslashreplace”, “xmlcharrefreplace”, and “surrogatepass” error handlers.
Issue #22540: speed up PyObject_IsInstance and PyObject_IsSubclass in the common case that the second argument has metaclass type.
Issue #18711: Add a new PyErr_FormatV function, similar to PyErr_Format but accepting a va_list argument.
Issue #22520: Fix overflow checking when generating the repr of a unicode object.
Issue #22519: Fix overflow checking in PyBytes_Repr.
Issue #22518: Fix integer overflow issues in latin-1 encoding.
Issue #16324: _charset parameter of MIMEText now also accepts email.charset.Charset instances. Initial patch by Claude Paroz.
Issue #1764286: Fix inspect.getsource() to support decorated functions. Patch by Claudiu Popa.
Issue #18554: os.__all__ includes posix functions.
Issue #21391: Use os.path.abspath in the shutil module.
Issue #11471: avoid generating a JUMP_FORWARD instruction at the end of an if-block if there is no else-clause. Original patch by Eugene Toder.
Issue #22215: Now ValueError is raised instead of TypeError when str or bytes argument contains not permitted null character or byte.
Issue #22258: Fix the internal function set_inheritable() on Illumos. This platform exposes the function ioctl(FIOCLEX), but calling it fails with errno is ENOTTY: “Inappropriate ioctl for device”. set_inheritable() now falls back to the slower fcntl() (F_GETFD and then F_SETFD).
Issue #21389: Displaying the __qualname__ of the underlying function in the repr of a bound method.
Issue #22206: Using pthread, PyThread_create_key() now sets errno to ENOMEM and returns -1 (error) on integer overflow.
Issue #20184: Argument Clinic based signature introspection added for 30 of the builtin functions.
Issue #22116: C functions and methods (of the ‘builtin_function_or_method’ type) can now be weakref’ed. Patch by Wei Wu.
Issue #22077: Improve index error messages for bytearrays, bytes, lists, and tuples by adding ‘or slices’. Added ‘, not 0. Patch by Demian Brecht.
Issue #15381: Optimized io.BytesIO to make less allocations and copyings.
Issue #22818: Splitting on a pattern that could match an empty string now raises a warning. Patterns that can only match empty strings are now rejected.
Issue #23099: Closing io.BytesIO with exported buffer is rejected now to prevent corrupting exported buffer.
Issue #23326: Removed __ne__ implementations. Since fixing default __ne__ implementation in issue #21408 they are redundant.
Issue #23363: Fix possible overflow in itertools.permutations.
Issue #23364: Fix possible overflow in itertools.product.
Issue #23366: Fixed possible integer overflow in itertools.combinations.
Issue #23366: Fixed possible integer overflow in itertools.combinations.
Issue #23369: Fixed possible integer overflow in _json.encode_basestring_ascii.
Issue #23353: Fix the exception handling of generators in PyEval_EvalFrameEx(). At entry, save or swap the exception state even if PyEval_EvalFrameEx() is called with throwflag=0. At exit, the exception state is now always restored or swapped, not only if why is WHY_YIELD or WHY_RETURN. Patch co-written with Antoine Pitrou.
Issue #14099: Restored support of writing ZIP files to tellable but non-seekable streams.
Issue #14099: Writing to ZipFile and reading multiple ZipExtFiles is threadsafe now.
Issue #19361: JSON decoder now raises JSONDecodeError instead of ValueError.
Issue #18518: timeit now rejects statements which can’t be compiled outside a function or a loop (e.g. “return” or “break”).
Issue #23094: Fixed readline with frames in Python implementation of pickle.
Issue #23268: Fixed bugs in the comparison of ipaddress classes.
Issue #21408: Removed incorrect implementations of __ne__() which didn’t returned NotImplemented if __eq__() returned NotImplemented. The default __ne__() now works correctly.
Issue #19996: email.feedparser.FeedParser now handles (malformed) headers with no key rather than amusing the body has started.
Issue #20188: Support Application-Layer Protocol Negotiation (ALPN) in the ssl module.
Issue #23133: Pickling of ipaddress objects now produces more compact and portable representation.
Issue #23248: Update ssl error codes from latest OpenSSL git master.
Issue #23266: Much faster implementation of ipaddress.collapse_addresses() when there are many non-consecutive addresses.
Issue #23098: 64-bit dev_t is now supported in the os module.
Issue #21817: When an exception is raised in a task submitted to a ProcessPoolExecutor, the remote traceback is now displayed in the parent process. Patch by Claudiu Popa.
Issue #15955: Add an option to limit output size when decompressing LZMA data. Patch by Nikolaus Rath and Martin Panter.
Issue #23250: In the http.cookies module, capitalize “HttpOnly” and “Secure” as they are written in the standard.
Issue #23063: In the disutils’ check command, fix parsing of reST with code or code-block directives.
Issue #23209, #23225: selectors.BaseSelector.get_key() now raises a RuntimeError if the selector is closed. And selectors.BaseSelector.close() now clears its internal reference to the selector mapping to break a reference cycle. Initial patch written by Martin Richard.
Issue #19777: Provide a home() classmethod on Path objects. Contributed by Victor Salgado and Mayank Tripathi.
Issue #23206: Make json.dumps(..., ensure_ascii=False) as fast as the default case of ensure_ascii=True. Patch by Naoki Inada.
Issue #23185: Add math.inf and math.nan constants.
Issue #23186: Add ssl.SSLObject.shared_ciphers() and ssl.SSLSocket.shared_ciphers() to fetch the client’s list ciphers sent at handshake.
Issue #23143: Remove compatibility with OpenSSLs older than 0.9.8.
Issue #23132: Improve performance and introspection support of comparison methods created by functool.total_ordering.
Issue #19776: Add a expanduser() method on Path objects.
Issue #23112: Fix SimpleHTTPServer to correctly carry the query string and fragment when it redirects to add a trailing slash.
Issue #21793: Added http.HTTPStatus enums (i.e. HTTPStatus.OK, HTTPStatus.NOT_FOUND). Patch by Demian Brecht.
Issue #23093: In the io, module allow more operations to work on detached streams.
Issue #23111: In the ftplib, make ssl.PROTOCOL_SSLv23 the default protocol version.
Issue #22585: On OpenBSD 5.6 and newer, os.urandom() now calls getentropy(), instead of reading /dev/urandom, to get pseudo-random bytes.
Issue #19104: pprint now produces evaluable output for wrapped strings.
Issue #23071: Added missing names to codecs.__all__. Patch by Martin Panter.
Issue #22783: Pickling now uses the NEWOBJ opcode instead of the NEWOBJ_EX opcode if possible.
Issue #15513: Added a __sizeof__ implementation for pickle classes.
Issue #19858: pickletools.optimize() now aware of the MEMOIZE opcode, can produce more compact result and no longer produces invalid output if input data contains MEMOIZE opcodes together with PUT or BINPUT opcodes.
Issue #22095: Fixed HTTPConnection.set_tunnel with default port. The port value in the host header was set to “None”. Patch by Demian Brecht.
Issue #23016: A warning no longer produces an AttributeError when the program is run with pythonw.exe.
Issue #21775: shutil.copytree(): fix crash when copying to VFAT. An exception handler assumed that that OSError objects always have a ‘winerror’ attribute. That is not the case, so the exception handler itself raised AttributeError when run on Linux (and, presumably, any other non-Windows OS). Patch by Greg Ward.
Issue #1218234: Fix inspect.getsource() to load updated source of reloaded module. Initial patch by Berker Peksag.
Issue #21740: Support wrapped callables in doctest. Patch by Claudiu Popa.
Issue #23009: Make sure selectors.EpollSelecrtor.select() works when no FD is registered.
Issue #22959: In the constructor of http.client.HTTPSConnection, prefer the context’s check_hostname attribute over the check_hostname parameter.
Issue #22696: Add function sys.is_finalizing() to know about interpreter shutdown.
Issue #16043: Add a default limit for the amount of data xmlrpclib.gzip_decode will return. This resolves CVE-2013-1753.
Issue #14099: ZipFile.open() no longer reopen the underlying file. Objects returned by ZipFile.open() can now operate independently of the ZipFile even if the ZipFile was created by passing in a file-like object as the first argument to the constructor.
Issue #22966: Fix __pycache__ pyc file name clobber when pyc_compile is asked to compile a source file containing multiple dots in the source file name.
Issue #21971: Update turtledemo doc and add module to the index.
Issue #21032. Fixed socket leak if HTTPConnection.getresponse() fails. Original patch by Martin Panter.
Issue #22407: Deprecated the use of re.LOCALE flag with str patterns or re.ASCII. It was newer worked.
Issue #22902: The “ip” command is now used on Linux to determine MAC address in uuid.getnode(). Pach by Bruno Cauet.
Issue #22960: Add a context argument to xmlrpclib.ServerProxy constructor.
Issue #22389: Add contextlib.redirect_stderr().
Issue #21356: Make ssl.RAND_egd() optional to support LibreSSL. The availability of the function is checked during the compilation. Patch written by Bernard Spil.
Issue #22915: SAX parser now supports files opened with file descriptor or bytes path.
Issue #22609: Constructors and update methods of mapping classes in the collections module now accept the self keyword argument.
Issue #22940: Add readline.append_history_file.
Issue #19676: Added the “namereplace” error handler.
Issue #22788: Add context parameter to logging.handlers.HTTPHandler.
Issue #22921: Allow SSLContext to take the hostname parameter even if OpenSSL doesn’t support SNI.
Issue #22894: TestCase.subTest() would cause the test suite to be stopped when in failfast mode, even in the absence of failures.
Issue #22796: HTTP cookie parsing is now stricter, in order to protect against potential injection attacks.
Issue #22370: Windows detection in pathlib is now more robust.
Issue #22841: Reject coroutines in asyncio add_signal_handler(). Patch by Ludovic.Gasc.
Issue #19494: Added urllib.request.HTTPBasicPriorAuthHandler. Patch by Matej Cepl.
Issue #22578: Added attributes to the re.error class.
Issue #22849: Fix possible double free in the io.TextIOWrapper constructor.
Issue #12728: Different Unicode characters having the same uppercase but different lowercase are now matched in case-insensitive regular expressions.
Issue #22821: Fixed fcntl() with integer argument on 64-bit big-endian platforms.
Issue #21650: Add an --sort-keys option to json.tool CLI.
Issue #22824: Updated reprlib output format for sets to use set literals. Patch contributed by Berker Peksag.
Issue #22824: Updated reprlib output format for arrays to display empty arrays without an unnecessary empty list. Suggested by Serhiy Storchaka.
Issue #22406: Fixed the uu_codec codec incorrectly ported to 3.x. Based on patch by Martin Panter.
Issue #17293: uuid.getnode() now determines MAC address on AIX using netstat. Based on patch by Aivars Kalvāns.
Issue #22769: Fixed ttk.Treeview.tag_has() when called without arguments.
Issue #22417: Verify certificates by default in httplib (PEP 476).
Issue #22775: Fixed unpickling of http.cookies.SimpleCookie with protocol 2 and above. Patch by Tim Graham.
Issue #22776: Brought excluded code into the scope of a try block in SysLogHandler.emit().
Issue #22665: Add missing get_terminal_size and SameFileError to shutil.__all__.
Issue #6623: Remove deprecated Netrc class in the ftplib module. Patch by Matt Chaput.
Issue #17381: Fixed handling of case-insensitive ranges in regular expressions.
Issue #22410: Module level functions in the re module now cache compiled locale-dependent regular expressions taking into account the locale.
Issue #22759: Query methods on pathlib.Path() (exists(), is_dir(), etc.) now return False when the underlying stat call raises NotADirectoryError.
Issue #8876: distutils now falls back to copying files when hard linking doesn’t work. This allows use with special filesystems such as VirtualBox shared folders.
Issue #22217: Implemented reprs of classes in the zipfile module.
Issue #22457: Honour load_tests in the start_dir of discovery.
Issue #18216: gettext now raises an error when a .mo file has an unsupported major version number. Patch by Aaron Hill.
Issue #13918: Provide a locale.delocalize() function which can remove locale-specific number formatting from a string representing a number, without then converting it to a specific type. Patch by Cédric Krier.
Issue #22676: Make the pickling of global objects which don’t have a __module__ attribute less slow.
Issue #18853: Fixed ResourceWarning in shlex.__nain__.
Issue #9351: Defaults set with set_defaults on an argparse subparser are no longer ignored when also set on the parent parser.
Issue #7559: unittest test loading ImportErrors are reported as import errors with their import exception rather than as attribute errors after the import has already failed.
Issue #19746: Make it possible to examine the errors from unittest discovery without executing the test suite. The new errors attribute on TestLoader exposes these non-fatal errors encountered during discovery.
Issue #21991: Make email.headerregistry’s header ‘params’ attributes be read-only (MappingProxyType). Previously the dictionary was modifiable but a new one was created on each access of the attribute.
Issue #22638: SSLv3 is now disabled throughout the standard library. It can still be enabled by instantiating a SSLContext manually.
Issue #22641: In asyncio, the default SSL context for client connections is now created using ssl.create_default_context(), for stronger security.
Issue #17401: Include closefd in io.FileIO repr.
Issue #21338: Add silent mode for compileall. quiet parameters of compile_{dir, file, path} functions now have a multilevel value. Also, -q option of the CLI now have a multilevel value. Patch by Thomas Kluyver.
Issue #20152: Convert the array and cmath modules to Argument Clinic.
Issue #18643: Add socket.socketpair() on Windows.
Issue #22435: Fix a file descriptor leak when SocketServer bind fails.
Issue #13096: Fixed segfault in CTypes POINTER handling of large values.
Issue #11694: Raise ConversionError in xdrlib as documented. Patch by Filip Gruszczyński and Claudiu Popa.
Issue #19380: Optimized parsing of regular expressions.
Issue #1519638: Now unmatched groups are replaced with empty strings in re.sub() and re.subn().
Issue #18615: sndhdr.what/whathdr now return a namedtuple.
Issue #22462: Fix pyexpat’s creation of a dummy frame to make it appear in exception tracebacks.
Issue #21965: Add support for in-memory SSL to the ssl module. Patch by Geert Jansen.
Issue #21173: Fix len() on a WeakKeyDictionary when .clear() was called with an iterator alive.
Issue #11866: Eliminated race condition in the computation of names for new threads.
Issue #21905: Avoid RuntimeError in pickle.whichmodule() when sys.modules is mutated while iterating. Patch by Olivier Grisel.
Issue #11271: concurrent.futures.Executor.map() now takes a chunksize argument to allow batching of tasks in child processes and improve performance of ProcessPoolExecutor. Patch by Dan O’Reilly.
Issue #21883: os.path.join() and os.path.relpath() now raise a TypeError with more helpful error message for unsupported or mismatched types of arguments.
Issue #22219: The zipfile module CLI now adds entries for directories (including empty directories) in ZIP file.
Issue #22449: In the ssl.SSLContext.load_default_certs, consult the enviromental variables SSL_CERT_DIR and SSL_CERT_FILE on Windows.
Issue #22508: The email.__version__ variable has been removed; the email code is no longer shipped separately from the stdlib, and __version__ hasn’t been updated in several releases.
Issue #20076: Added non derived UTF-8 aliases to locale aliases table.
Issue #20079: Added locales supported in glibc 2.18 to locale alias table.
Issue #20218: Added convenience methods read_text/write_text and read_bytes/ write_bytes to pathlib.Path objects.
Issue #22437: Number of capturing groups in regular expression is no longer limited by 100.
Issue #17442: InteractiveInterpreter now displays the full chained traceback in its showtraceback method, to match the built in interactive interpreter.
Issue #23392: Added tests for marshal C API that works with FILE*.
Issue #10510: distutils register and upload methods now use HTML standards compliant CRLF line endings.
Issue #9850: Fixed macpath.join() for empty first component. Patch by Oleg Oshmyan.
Issue #5309: distutils’ build and build_ext commands now accept a -j option to enable parallel building of extension modules.
Issue #22448: Improve canceled timer handles cleanup to prevent unbound memory usage. Patch by Joshua Moore-Oliva.
Issue #22427: TemporaryDirectory no longer attempts to clean up twice when used in the with statement in generator.
Issue #22362: Forbidden ambiguous octal escapes out of range 0-0o377 in regular expressions.
Issue #20912: Now directories added to ZIP file have correct Unix and MS-DOS directory attributes.
Issue #21866: ZipFile.close() no longer writes ZIP64 central directory records if allowZip64 is false.
Issue #22278: Fix urljoin problem with relative urls, a regression observed after changes to issue22118 were submitted.
Issue #22415: Fixed debugging output of the GROUPREF_EXISTS opcode in the re module. Removed trailing spaces in debugging output.
Issue #22423: Unhandled exception in thread no longer causes unhandled AttributeError when sys.stderr is None.
Issue #21332: Ensure that bufsize=1 in subprocess.Popen() selects line buffering, rather than block buffering. Patch by Akira Li.
Issue #21091: Fix API bug: email.message.EmailMessage.is_attachment is now a method.
Issue #21079: Fix email.message.EmailMessage.is_attachment to return the correct result when the header has parameters as well as a value.
Issue #22247: Add NNTPError to nntplib.__all__.
Issue #22366: urllib.request.urlopen will accept a context object (SSLContext) as an argument which will then used be for HTTPS connection. Patch by Alex Gaynor.
Issue #4180: The warnings registries are now reset when the filters are modified.
Issue #22419: Limit the length of incoming HTTP request in wsgiref server to 65536 bytes and send a 414 error code for higher lengths. Patch contributed by Devin Cook.
Lax cookie parsing in http.cookies could be a security issue when combined with non-standard cookie handling in some Web browsers. Reported by Sergey Bobrov.
Issue #20537: logging methods now accept an exception instance as well as a Boolean value or exception tuple. Thanks to Yury Selivanov for the patch.
Issue #22384: An exception in Tkinter callback no longer crashes the program when it is run with pythonw.exe.
Issue #22168: Prevent turtle AttributeError with non-default Canvas on OS X.
Issue #21147: sqlite3 now raises an exception if the request contains a null character instead of truncate it. Based on patch by Victor Stinner.
Issue #13968: The glob module now supports recursive search in subdirectories using the “**” pattern.
Issue #21951: Fixed a crash in Tkinter on AIX when called Tcl command with empty string or tuple argument.
Issue #21951: Tkinter now most likely raises MemoryError instead of crash if the memory allocation fails.
Issue #22338: Fix a crash in the json module on memory allocation failure.
Issue #12410: imaplib.IMAP4 now supports the context management protocol. Original patch by Tarek Ziadé.
Issue #21270: We now override tuple methods in mock.call objects so that they can be used as normal call attributes.
Issue #16662: load_tests() is now unconditionally run when it is present in a package’s __init__.py. TestLoader.loadTestsFromModule() still accepts use_load_tests, but it is deprecated and ignored. A new keyword-only attribute pattern is added and documented. Patch given by Robert Collins, tweaked by Barry Warsaw.
Issue #22226: First letter no longer is stripped from the “status” key in the result of Treeview.heading().
Issue #19524: Fixed resource leak in the HTTP connection when an invalid response is received. Patch by Martin Panter.
Issue #20421: Add a .version() method to SSL sockets exposing the actual protocol version in use.
Issue #19546: configparser exceptions no longer expose implementation details. Chained KeyErrors are removed, which leads to cleaner tracebacks. Patch by Claudiu Popa.
Issue #22051: turtledemo no longer reloads examples to re-run them. Initialization of variables and gui setup should be done in main(), which is called each time a demo is run, but not on import.
Issue #21933: Turtledemo users can change the code font size with a menu selection or control(command) ‘-‘ or ‘+’ or control-mousewheel. Original patch by Lita Cho.
Issue #21597: The separator between the turtledemo text pane and the drawing canvas can now be grabbed and dragged with a mouse. The code text pane can be widened to easily view or copy the full width of the text. The canvas can be widened on small screens. Original patches by Jan Kanis and Lita Cho.
Issue #18132: Turtledemo buttons no longer disappear when the window is shrunk. Original patches by Jan Kanis and Lita Cho.
Issue #22043: time.monotonic() is now always available. threading.Lock.acquire(), threading.RLock.acquire() and socket operations now use a monotonic clock, instead of the system clock, when a timeout is used.
Issue #21527: Add a default number of workers to ThreadPoolExecutor equal to 5 times the number of CPUs. Patch by Claudiu Popa.
Issue #22216: smtplib now resets its state more completely after a quit. The most obvious consequence of the previous behavior was a STARTTLS failure during a connect/starttls/quit/connect/starttls sequence.
Issue #22098: ctypes’ BigEndianStructure and LittleEndianStructure now define an empty __slots__ so that subclasses don’t always get an instance dict. Patch by Claudiu Popa.
Issue #22185: Fix an occasional RuntimeError in threading.Condition.wait() caused by mutation of the waiters queue without holding the lock. Patch by Doug Zongker.
Issue #22287: On UNIX, _PyTime_gettimeofday() now uses clock_gettime(CLOCK_REALTIME) if available. As a side effect, Python now depends on the librt library on Solaris and on Linux (only with glibc older than 2.17).
Issue #22182: Use e.args to unpack exceptions correctly in distutils.file_util.move_file. Patch by Claudiu Popa.
The webbrowser module now uses subprocess’s start_new_session=True rather than a potentially risky preexec_fn=os.setsid call.
Issue #22042: signal.set_wakeup_fd(fd) now raises an exception if the file descriptor is in blocking mode.
Issue #16808: inspect.stack() now returns a named tuple instead of a tuple. Patch by Daniel Shahaf.
Issue #22236: Fixed Tkinter images copying operations in NoDefaultRoot mode.
Issue #2527: Add a globals argument to timeit functions, in order to override the globals namespace in which the timed code is executed. Patch by Ben Roberts.
Issue #22118: Switch urllib.parse to use RFC 3986 semantics for the resolution of relative URLs, rather than RFCs 1808 and 2396. Patch by Demian Brecht.
Issue #21549: Added the “members” parameter to TarFile.list().
Issue #19628: Allow compileall recursion depth to be specified with a -r option.
Issue #15696: Add a __sizeof__ implementation for mmap objects on Windows.
Issue #22068: Avoided reference loops with Variables and Fonts in Tkinter.
Issue #22165: SimpleHTTPRequestHandler now supports undecodable file names.
Issue #15381: Optimized line reading in io.BytesIO.
Issue #8797: Raise HTTPError on failed Basic Authentication immediately. Initial patch by Sam Bull.
Issue #20729: Restored the use of lazy iterkeys()/itervalues()/iteritems() in the mailbox module.
Issue #21448: Changed FeedParser feed() to avoid O(N**2) behavior when parsing long line. Original patch by Raymond Hettinger.
Issue #22184: The functools LRU Cache decorator factory now gives an earlier and clearer error message when the user forgets the required parameters.
Issue #17923: glob() patterns ending with a slash no longer match non-dirs on AIX. Based on patch by Delhallt.
Issue #21725: Added support for RFC 6531 (SMTPUTF8) in smtpd.
Issue #22176: Update the ctypes module’s libffi to v3.1. This release adds support for the Linux AArch64 and POWERPC ELF ABIv2 little endian architectures.
Issue #5411: Added support for the “xztar” format in the shutil module.
Issue #21121: Don’t force 3rd party C extensions to be built with -Werror=declaration-after-statement.
Issue #21975: Fixed crash when using uninitialized sqlite3.Row (in particular when unpickling pickled sqlite3.Row). sqlite3.Row is now initialized in the __new__() method.
Issue #20170: Convert posixmodule to use Argument Clinic.
Issue #21539: Add a exists_ok argument to Pathlib.mkdir() to mimic mkdir -p and os.makedirs() functionality. When true, ignore FileExistsErrors. Patch by Berker Peksag.
Issue #22127: Bypass IDNA for pure-ASCII host names in the socket module (in particular for numeric IPs).
Issue #21047: set the default value for the convert_charrefs argument of HTMLParser to True. Patch by Berker Peksag.
Add an __all__ to html.entities.
Issue #15114: the strict mode and argument of HTMLParser, HTMLParser.error, and the HTMLParserError exception have been removed.
Issue #22085: Dropped support of Tk 8.3 in Tkinter.
Issue #21580: Now Tkinter correctly handles bytes arguments passed to Tk. In particular this allows to initialize images from binary data.
Issue #22003: When initialized from a bytes object, io.BytesIO() now defers making a copy until it is mutated, improving performance and memory use on some use cases. Patch by David Wilson.
Issue #22018: On Windows, signal.set_wakeup_fd() now also supports sockets. A side effect is that Python depends to the WinSock library.
Issue #22054: Add os.get_blocking() and os.set_blocking() functions to get and set the blocking mode of a file descriptor (False if the O_NONBLOCK flag is set, True otherwise). These functions are not available on Windows.
Issue #17172: Make turtledemo start as active on OS X even when run with subprocess. Patch by Lita Cho.
Issue #21704: Fix build error for _multiprocessing when semaphores are not available. Patch by Arfrever Frehtes Taifersar Arahesis.
Issue #20173: Convert sha1, sha256, sha512 and md5 to ArgumentClinic. Patch by Vajrasky Kok.
Fix repr(_socket.socket) on Windows 64-bit: don’t fail with OverflowError on closed socket. repr(socket.socket) already works fine.
Issue #22033: Reprs of most Python implemened classes now contain actual class name instead of hardcoded one.
Issue #21947: The dis module can now disassemble generator-iterator objects based on their gi_code attribute. Patch by Clement Rouault.
Issue #16133: The asynchat.async_chat.handle_read() method now ignores BlockingIOError exceptions.
Issue #22044: Fixed premature DECREF in call_tzinfo_method. Patch by Tom Flanagan.
Issue #19884: readline: Disable the meta modifier key if stdout is not a terminal to not write the ANSI sequence “033[1034h” into stdout. This sequence is used on some terminal (ex: TERM=xterm-256color”) to enable support of 8 bit characters.
Issue #4350: Removed a number of out-of-dated and non-working for a long time Tkinter methods.
Issue #6167: Scrollbar.activate() now returns the name of active element if the argument is not specified. Scrollbar.set() now always accepts only 2 arguments.
Issue #15275: Clean up and speed up the ntpath module.
Issue #21888: plistlib’s load() and loads() now work if the fmt parameter is specified.
Issue #22032: __qualname__ instead of __name__ is now always used to format fully qualified class names of Python implemented classes.
Issue #22031: Reprs now always use hexadecimal format with the “0x” prefix when contain an id in form ” at 0x...”.
Issue #22018: signal.set_wakeup_fd() now raises an OSError instead of a ValueError on fstat() failure.
Issue #21044: tarfile.open() now handles fileobj with an integer ‘name’ attribute. Based on patch by Antoine Pietri.
Issue #21966: Respect -q command-line option when code module is ran.
Issue #19076: Don’t pass the redundant ‘file’ argument to self.error().
Issue #16382: Improve exception message of warnings.warn() for bad category. Initial patch by Phil Elson.
Issue #21932: os.read() now uses a Py_ssize_t() type instead of int for the size to support reading more than 2 GB at once. On Windows, the size is truncted to INT_MAX. As any call to os.read(), the OS may read less bytes than the number of requested bytes.
Issue #21942: Fixed source file viewing in pydoc’s server mode on Windows.
Issue #11259: asynchat.async_chat().set_terminator() now raises a ValueError if the number of received bytes is negative.
Issue #12523: asynchat.async_chat.push() now raises a TypeError if it doesn’t get a bytes string
Issue #21707: Add missing kwonlyargcount argument to ModuleFinder.replace_paths_in_code().
Issue #20639: calling Path.with_suffix(‘’) allows removing the suffix again. Patch by July Tikhonov.
Issue #21714: Disallow the construction of invalid paths using Path.with_name(). Original patch by Antony Lee.
Issue #15014: Added ‘auth’ method to smtplib to make implementing auth mechanisms simpler, and used it internally in the login method.
Issue #21151: Fixed a segfault in the winreg module when None is passed as a REG_BINARY value to SetValueEx. Patch by John Ehresman.
Issue #21090: io.FileIO.readall() does not ignore I/O errors anymore. Before, it ignored I/O errors if at least the first C call read() succeed.
Issue #5800: headers parameter of wsgiref.headers.Headers is now optional. Initial patch by Pablo Torres Navarrete and SilentGhost.
Issue #21781: ssl.RAND_add() now supports strings longer than 2 GB.
Issue #21679: Prevent extraneous fstat() calls during open(). Patch by Bohuslav Kabrda.
Issue #21863: cProfile now displays the module name of C extension functions, in addition to their own name.
Issue #11453: asyncore: emit a ResourceWarning when an unclosed file_wrapper object is destroyed. The destructor now closes the file if needed. The close() method can now be called twice: the second call does nothing.
Issue #21858: Better handling of Python exceptions in the sqlite3 module.
Issue #21476: Make sure the email.parser.BytesParser TextIOWrapper is discarded after parsing, so the input file isn’t unexpectedly closed.
Issue #20295: imghdr now recognizes OpenEXR format images.
Issue #21729: Used the “with” statement in the dbm.dumb module to ensure files closing. Patch by Claudiu Popa.
Issue #21491: socketserver: Fix a race condition in child processes reaping.
Issue #21719: Added the st_file_attributes field to os.stat_result on Windows.
Issue #21832: Require named tuple inputs to be exact strings.
Issue #21722: The distutils “upload” command now exits with a non-zero return code when uploading fails. Patch by Martin Dengler.
Issue #21723: asyncio.Queue: support any type of number (ex: float) for the maximum size. Patch written by Vajrasky Kok.
Issue #21711: support for “site-python” directories has now been removed from the site module (it was deprecated in 3.4).
Issue #17552: new socket.sendfile() method allowing to send a file over a socket by using high-performance os.sendfile() on UNIX. Patch by Giampaolo Rodola’.
Issue #18039: dbm.dump.open() now always creates a new database when the flag has the value ‘n’. Patch by Claudiu Popa.
Issue #21326: Add a new is_closed() method to asyncio.BaseEventLoop. run_forever() and run_until_complete() methods of asyncio.BaseEventLoop now raise an exception if the event loop was closed.
Issue #21766: Prevent a security hole in CGIHTTPServer by URL unquoting paths before checking for a CGI script at that path.
Issue #21310: Fixed possible resource leak in failed open().
Issue #21256: Printout of keyword args should be in deterministic order in a mock function call. This will help to write better doctests.
Issue #21677: Fixed chaining nonnormalized exceptions in io close() methods.
Issue #11709: Fix the pydoc.help function to not fail when sys.stdin is not a valid file.
Issue #21515: tempfile.TemporaryFile now uses os.O_TMPFILE flag is available.
Issue #13223: Fix pydoc.writedoc so that the HTML documentation for methods that use ‘self’ in the example code is generated correctly.
Issue #21463: In urllib.request, fix pruning of the FTP cache.
Issue #21618: The subprocess module could fail to close open fds that were inherited by the calling process and already higher than POSIX resource limits would otherwise allow. On systems with a functioning /proc/self/fd or /dev/fd interface the max is now ignored and all fds are closed.
Issue #20383: Introduce importlib.util.module_from_spec() as the preferred way to create a new module.
Issue #21552: Fixed possible integer overflow of too long string lengths in the tkinter module on 64-bit platforms.
Issue #14315: The zipfile module now ignores extra fields in the central directory that are too short to be parsed instead of letting a struct.unpack error bubble up as this “bad data” appears in many real world zip files in the wild and is ignored by other zip tools.
Issue #13742: Added “key” and “reverse” parameters to heapq.merge(). (First draft of patch contributed by Simon Sapin.)
Issue #21402: tkinter.ttk now works when default root window is not set.
Issue #3015: _tkinter.create() now creates tkapp object with wantobject=1 by default.
Issue #10203: sqlite3.Row now truly supports sequence protocol. In particulr it supports reverse() and negative indices. Original patch by Claudiu Popa.
Issue #18807: If copying (no symlinks) specified for a venv, then the python interpreter aliases (python, python3) are now created by copying rather than symlinking.
Issue #20197: Added support for the WebP image type in the imghdr module. Patch by Fabrice Aneche and Claudiu Popa.
Issue #21513: Speedup some properties of IP addresses (IPv4Address, IPv6Address) such as .is_private or .is_multicast.
Issue #21137: Improve the repr for threading.Lock() and its variants by showing the “locked” or “unlocked” status. Patch by Berker Peksag.
Issue #21538: The plistlib module now supports loading of binary plist files when reference or offset size is not a power of two.
Issue #21455: Add a default backlog to socket.listen().
Issue #21525: Most Tkinter methods which accepted tuples now accept lists too.
Issue #22166: with the assistance of a new internal _codecs._forget_codec helping function, test_codecs now clears the encoding caches to avoid the appearance of a reference leak
Issue #22236: Tkinter tests now don’t reuse default root window. New root window is created for every test class.
Issue #10744: Fix PEP 3118 format strings on ctypes objects with a nontrivial shape.
Issue #20826: Optimize ipaddress.collapse_addresses().
Issue #21487: Optimize ipaddress.summarize_address_range() and ipaddress.{IPv4Network,IPv6Network}.subnets().
Issue #21486: Optimize parsing of netmasks in ipaddress.IPv4Network and ipaddress.IPv6Network.
Issue #13916: Disallowed the surrogatepass error handler for non UTF-* encodings.
Issue #20998: Fixed re.fullmatch() of repeated single character pattern with ignore case. Original patch by Matthew Barnett.
Issue #21075: fileinput.FileInput now reads bytes from standard stream if binary mode is specified. Patch by Sam Kimbrel.
Issue #19775: Add a samefile() method to pathlib Path objects. Initial patch by Vajrasky Kok.
Issue #21226: Set up modules properly in PyImport_ExecCodeModuleObject (and friends).
Issue #21398: Fix an unicode error in the pydoc pager when the documentation contains characters not encodable to the stdout encoding.
Issue #16531: ipaddress.IPv4Network and ipaddress.IPv6Network now accept an (address, netmask) tuple argument, so as to easily construct network objects from existing addresses.
Issue #21156: importlib.abc.InspectLoader.source_to_code() is now a staticmethod.
Issue #21424: Simplified and optimized heaqp.nlargest() and nmsmallest() to make fewer tuple comparisons.
Issue #21396: Fix TextIOWrapper(..., write_through=True) to not force a flush() on the underlying binary stream. Patch by akira.
Issue #18314: Unlink now removes junctions on Windows. Patch by Kim Gräsman
Issue #21088: Bugfix for curses.window.addch() regression in 3.4.0. In porting to Argument Clinic, the first two arguments were reversed.
Issue #21407: _decimal: The module now supports function signatures.
Issue #10650: Remove the non-standard ‘watchexp’ parameter from the Decimal.quantize() method in the Python version. It had never been present in the C version.
Issue #21469: Reduced the risk of false positives in robotparser by checking to make sure that robots.txt has been read or does not exist prior to returning True in can_fetch().
Issue #19414: Have the OrderedDict mark deleted links as unusable. This gives an early failure if the link is deleted during iteration.
Issue #21421: Add __slots__ to the MappingViews ABC. Patch by Josh Rosenberg.
Issue #21101: Eliminate double hashing in the C speed-up code for collections.Counter().
Issue #21321: itertools.islice() now releases the reference to the source iterator when the slice is exhausted. Patch by Anton Afanasyev.
Issue #21057: TextIOWrapper now allows the underlying binary stream’s read() or read1() method to return an arbitrary bytes-like object (such as a memoryview). Patch by Nikolaus Rath.
Issue #20951: SSLSocket.send() now raises either SSLWantReadError or SSLWantWriteError on a non-blocking socket if the operation would block. Previously, it would return 0. Patch by Nikolaus Rath.
Issue #13248: removed previously deprecated asyncore.dispatcher __getattr__ cheap inheritance hack.
Issue #9815: assertRaises now tries to clear references to local variables in the exception’s traceback.
Issue #19940: ssl.cert_time_to_seconds() now interprets the given time string in the UTC timezone (as specified in RFC 5280), not the local timezone.
Issue #13204: Calling sys.flags.__new__ would crash the interpreter, now it raises a TypeError.
Issue #19385: Make operations on a closed dbm.dumb database always raise the same exception.
Issue #21207: Detect when the os.urandom cached fd has been closed or replaced, and open it anew.
Issue #21291: subprocess’s Popen.wait() is now thread safe so that multiple threads may be calling wait() or poll() on a Popen instance at the same time without losing the Popen.returncode value.
Issue #21127: Path objects can now be instantiated from str subclass instances (such as numpy.str_).
Issue #15002: urllib.response object to use _TemporaryFileWrapper (and _TemporaryFileCloser) facility. Provides a better way to handle file descriptor close. Patch contributed by Christian Theune.
Issue #12220: mindom now raises a custom ValueError indicating it doesn’t support spaces in URIs instead of letting a ‘split’ ValueError bubble up.
Issue #21068: The ssl.PROTOCOL* constants are now enum members.
Issue #21276: posixmodule: Don’t define USE_XATTRS on KFreeBSD and the Hurd.
Issue #21262: New method assert_not_called for Mock. It raises AssertionError if the mock has been called.
Issue #21238: New keyword argument unsafe to Mock. It raises AttributeError incase of an attribute startswith assert or assret.
Issue #20896: ssl.get_server_certificate() now uses PROTOCOL_SSLv23, not PROTOCOL_SSLv3, for maximum compatibility.
Issue #21239: patch.stopall() didn’t work deterministically when the same name was patched more than once.
Issue #21203: Updated fileConfig and dictConfig to remove inconsistencies. Thanks to Jure Koren for the patch.
Issue #21222: Passing name keyword argument to mock.create_autospec now works.
Issue #21197: Add lib64 -> lib symlink in venvs on 64-bit non-OS X POSIX.
Issue #17498: Some SMTP servers disconnect after certain errors, violating strict RFC conformance. Instead of losing the error code when we issue the subsequent RSET, smtplib now returns the error code and defers raising the SMTPServerDisconnected error until the next command is issued.
Issue #17826: setting an iterable side_effect on a mock function created by create_autospec now works. Patch by Kushal Das.
Issue #7776: Fix Host: header and reconnection when using http.client.HTTPConnection.set_tunnel(). Patch by Nikolaus Rath.
Issue #20968: unittest.mock.MagicMock now supports division. Patch by Johannes Baiter.
Fix arbitrary memory access in JSONDecoder.raw_decode with a negative second parameter. Bug reported by Guido Vranken.
Issue #21169: getpass now handles non-ascii characters that the input stream encoding cannot encode by re-encoding using the replace error handler.
Issue #21171: Fixed undocumented filter API of the rot13 codec. Patch by Berker Peksag.
Issue #20539: Improved math.factorial error message for large positive inputs and changed exception type (OverflowError -> ValueError) for large negative inputs.
Issue #21172: isinstance check relaxed from dict to collections.Mapping.
Issue #21155: asyncio.EventLoop.create_unix_server() now raises a ValueError if path and sock are specified at the same time.
Issue #21136: Avoid unnecessary normalization of Fractions resulting from power and other operations. Patch by Raymond Hettinger.
Issue #17621: Introduce importlib.util.LazyLoader.
Issue #21076: signal module constants were turned into enums. Patch by Giampaolo Rodola’.
Issue #20636: Improved the repr of Tkinter widgets.
Issue #19505: The items, keys, and values views of OrderedDict now support reverse iteration using reversed().
Issue #21149: Improved thread-safety in logging cleanup during interpreter shutdown. Thanks to Devin Jeanpierre for the patch.
Issue #21058: Fix a leak of file descriptor in tempfile.NamedTemporaryFile(), close the file descriptor if io.open() fails
Issue #21200: Return None from pkgutil.get_loader() when __spec__ is missing.
Issue #21013: Enhance ssl.create_default_context() when used for server side sockets to provide better security by default.
Issue #20145: assertRaisesRegex and assertWarnsRegex now raise a TypeError if the second argument is not a string or compiled regex.
Issue #20633: Replace relative import by absolute import.\
Issue #20980: Stop wrapping exception when using ThreadPool.
Issue #21082: In os.makedirs, do not set the process-wide umask. Note this changes behavior of makedirs when exist_ok=True.
Issue #20990: Fix issues found by pyflakes for multiprocessing.
Issue #21015: SSL contexts will now automatically select an elliptic curve for ECDH key exchange on OpenSSL 1.0.2 and later, and otherwise default to “prime256v1”.
Issue #21000: Improve the command-line interface of json.tool.
Issue #20995: Enhance default ciphers used by the ssl module to enable better security an prioritize perfect forward secrecy.
Issue #20884: Don’t assume that __file__ is defined on importlib.__init__.
Issue #21499: Ignore __builtins__ in several test_importlib.test_api tests.
Issue #20627: xmlrpc.client.ServerProxy is now a context manager.
Issue #19165: The formatter module now raises DeprecationWarning instead of PendingDeprecationWarning.
Issue #13936: Remove the ability of datetime.time instances to be considered false in boolean contexts.
Issue 18931: selectors module now supports /dev/poll on Solaris. Patch by Giampaolo Rodola’.
Issue #19977: When the LC_TYPE locale is the POSIX locale (C locale), sys.stdin and sys.stdout are now using the surrogateescape error handler, instead of the strict error handler.
Issue #20574: Implement incremental decoder for cp65001 code (Windows code page 65001, Microsoft UTF-8).
Issue #20879: Delay the initialization of encoding and decoding tables for base32, ascii85 and base85 codecs in the base64 module, and delay the initialization of the unquote_to_bytes() table of the urllib.parse module, to not waste memory if these modules are not used.
Issue #19157: Include the broadcast address in the usuable hosts for IPv6 in ipaddress.
Issue #11599: When an external command (e.g. compiler) fails, distutils now prints out the whole command line (instead of just the command name) if the environment variable DISTUTILS_DEBUG is set.
Issue #4931: distutils should not produce unhelpful “error: None” messages anymore. distutils.util.grok_environment_error is kept but doc-deprecated.
Issue #20875: Prevent possible gzip “‘read’ is not defined” NameError. Patch by Claudiu Popa.
Issue #11558: email.message.Message.attach now returns a more useful error message if attach is called on a message for which is_multipart is False.
Issue #20283: RE pattern methods now accept the string keyword parameters as documented. The pattern and source keyword parameters are left as deprecated aliases.
Issue #20778: Fix modulefinder to work with bytecode-only modules.
Issue #20791: copy.copy() now doesn’t make a copy when the input is a bytes object. Initial patch by Peter Otten.
Issue #19748: On AIX, time.mktime() now raises an OverflowError for year outsize range [1902; 2037].
Issue #19573: inspect.signature: Use enum for parameter kind constants.
Issue #20726: inspect.signature: Make Signature and Parameter picklable.
Issue #17373: Add inspect.Signature.from_callable method.
Issue #20378: Improve repr of inspect.Signature and inspect.Parameter.
Issue #20816: Fix inspect.getcallargs() to raise correct TypeError for missing keyword-only arguments. Patch by Jeremiah Lowin.
Issue #20817: Fix inspect.getcallargs() to fail correctly if more than 3 arguments are missing. Patch by Jeremiah Lowin.
Issue #6676: Ensure a meaningful exception is raised when attempting to parse more than one XML document per pyexpat xmlparser instance. (Original patches by Hirokazu Yamamoto and Amaury Forgeot d’Arc, with suggested wording by David Gutteridge)
Issue #21117: Fix inspect.signature to better support functools.partial. Due to the specifics of functools.partial implementation, positional-or-keyword arguments passed as keyword arguments become keyword-only.
Issue #20334: inspect.Signature and inspect.Parameter are now hashable. Thanks to Antony Lee for bug reports and suggestions.
Issue #15916: doctest.DocTestSuite returns an empty unittest.TestSuite instead of raising ValueError if it finds no tests
Issue #21209: Fix asyncio.tasks.CoroWrapper to workaround a bug in yield-from implementation in CPythons prior to 3.4.1.
asyncio: Add gi_{frame,running,code} properties to CoroWrapper (upstream issue #163).
Issue #21311: Avoid exception in _osx_support with non-standard compiler configurations. Patch by John Szakmeister.
Issue #11571: Ensure that the turtle window becomes the topmost window when launched on OS X.
Issue #21801: Validate that __signature__ is None or an instance of Signature.
Issue #21923: Prevent AttributeError in distutils.sysconfig.customize_compiler due to possible uninitialized _config_vars.
Issue #21323: Fix http.server to again handle scripts in CGI subdirectories, broken by the fix for security issue #19435. Patch by Zach Byrne.
Issue #22733: Fix ffi_prep_args not zero-extending argument values correctly on 64-bit Windows.
Issue #23302: Default to TCP_NODELAY=1 upon establishing an HTTPConnection. Removed use of hard-coded MSS as it’s an optimization that’s no longer needed with Nagle disabled.
IDLE:
Issue #20577: Configuration of the max line length for the FormatParagraph extension has been moved from the General tab of the Idle preferences dialog to the FormatParagraph tab of the Config Extensions dialog. Patch by Tal Einat.
Issue #16893: Update Idle doc chapter to match current Idle and add new information.
Issue #3068: Add Idle extension configuration dialog to Options menu. Changes are written to HOME/.idlerc/config-extensions.cfg. Original patch by Tal Einat.
Issue #16233: A module browser (File : Class Browser, Alt+C) requires a editor window with a filename. When Class Browser is requested otherwise, from a shell, output window, or ‘Untitled’ editor, Idle no longer displays an error box. It now pops up an Open Module box (Alt+M). If a valid name is entered and a module is opened, a corresponding browser is also opened.
Issue #4832: Save As to type Python files automatically adds .py to the name you enter (even if your system does not display it). Some systems automatically add .txt when type is Text files.
Issue #21986: Code objects are not normally pickled by the pickle module. To match this, they are no longer pickled when running under Idle.
Issue #17390: Adjust Editor window title; remove ‘Python’, move version to end.
Issue #14105: Idle debugger breakpoints no longer disappear when inseting or deleting lines.
Issue #17172: Turtledemo can now be run from Idle. Currently, the entry is on the Help menu, but it may move to Run. Patch by Ramchandra Apt and Lita Cho.
Issue #21765: Add support for non-ascii identifiers to HyperParser.
Issue #21940: Add unittest for WidgetRedirector. Initial patch by Saimadhav Heblikar.
Issue #18592: Add unittest for SearchDialogBase. Patch by Phil Webster.
Issue #21694: Add unittest for ParenMatch. Patch by Saimadhav Heblikar.
Issue #21686: add unittest for HyperParser. Original patch by Saimadhav Heblikar.
Issue #12387: Add missing upper(lower)case versions of default Windows key bindings for Idle so Caps Lock does not disable them. Patch by Roger Serwy.
Issue #21695: Closing a Find-in-files output window while the search is still in progress no longer closes Idle.
Issue #18910: Add unittest for textView. Patch by Phil Webster.
Issue #18292: Add unittest for AutoExpand. Patch by Saihadhav Heblikar.
Issue #18409: Add unittest for AutoComplete. Patch by Phil Webster.
Issue #21477: htest.py - Improve framework, complete set of tests. Patches by Saimadhav Heblikar
Issue #18104: Add idlelib/idle_test/htest.py with a few sample tests to begin consolidating and improving human-validated tests of Idle. Change other files as needed to work with htest. Running the module as __main__ runs all tests.
Issue #21139: Change default paragraph width to 72, the PEP 8 recommendation.
Issue #21284: Paragraph reformat test passes after user changes reformat width.
Issue #17654: Ensure IDLE menus are customized properly on OS X for non-framework builds and for all variants of Tk.
Issue #23180: Rename IDLE “Windows” menu item to “Window”. Patch by Al Sweigart.
Build:
Issue #15506: Use standard PKG_PROG_PKG_CONFIG autoconf macro in the configure script.
Issue #22935: Allow the ssl module to be compiled if openssl doesn’t support SSL 3.
Issue #22592: Drop support of the Borland C compiler to build Python. The distutils module still supports it to build extensions.
Issue #22591: Drop support of MS-DOS, especially of the DJGPP compiler (MS-DOS port of GCC).
Issue #16537: Check whether self.extensions is empty in setup.py. Patch by Jonathan Hosmer.
Issue #22359: Remove incorrect uses of recursive make. Patch by Jonas Wagner.
Issue #21958: Define HAVE_ROUND when building with Visual Studio 2013 and above. Patch by Zachary Turner.
Issue #18093: the programs that embed the CPython runtime are now in a separate “Programs” directory, rather than being kept in the Modules directory.
Issue #15759: “make suspicious”, “make linkcheck” and “make doctest” in Doc/ now display special message when and only when there are failures.
Issue #21141: The Windows build process no longer attempts to find Perl, instead relying on OpenSSL source being configured and ready to build. The PCbuild\build_ssl.py script has been re-written and re-named to PCbuild\prepare_ssl.py, and takes care of configuring OpenSSL source for both 32 and 64 bit platforms. OpenSSL sources obtained from svn.python.org will always be pre-configured and ready to build.
Issue #21037: Add a build option to enable AddressSanitizer support.
Issue #19962: The Windows build process now creates “python.bat” in the root of the source tree, which passes all arguments through to the most recently built interpreter.
Issue #21285: Refactor and fix curses configure check to always search in a ncursesw directory.
Issue #15234: For BerkelyDB and Sqlite, only add the found library and include directories if they aren’t already being searched. This avoids an explicit runtime library dependency.
Issue #17861: Tools/scripts/generate_opcode_h.py automatically regenerates Include/opcode.h from Lib/opcode.py if the later gets any change.
Issue #20644: OS X installer build support for documentation build changes in 3.4.1: assume externally supplied sphinx-build is available in /usr/bin.
Issue #20022: Eliminate use of deprecated bundlebuilder in OS X builds.
Issue #15968: Incorporated Tcl, Tk, and Tix builds into the Windows build solution.
Issue #17095: Fix Modules/Setup shared support.
Issue #21811: Anticipated fixes to support OS X versions > 10.9.
Issue #21166: Prevent possible segfaults and other random failures of python –generate-posix-vars in pybuilddir.txt build target.
Issue #18096: Fix library order returned by python-config.
Issue #17219: Add library build dir for Python extension cross-builds.
Issue #22919: Windows build updated to support VC 14.0 (Visual Studio 2015), which will be used for the official release.
Issue #21236: Build _msi.pyd with cabinet.lib instead of fci.lib
Issue #17128: Use private version of OpenSSL for OS X 10.5+ installer.
C API:
Issue #14203: Remove obsolete support for view==NULL in PyBuffer_FillInfo(), bytearray_getbuffer(), bytesiobuf_getbuffer() and array_buffer_getbuf(). All functions now raise BufferError in that case.
Issue #22445: PyBuffer_IsContiguous() now implements precise contiguity tests, compatible with NumPy’s NPY_RELAXED_STRIDES_CHECKING compilation flag. Previously the function reported false negatives for corner cases.
Issue #22079: PyType_Ready() now checks that statically allocated type has no dynamically allocated bases.
Issue #22453: Removed non-documented macro PyObject_REPR().
Issue #18395: Rename _Py_char2wchar() to Py_DecodeLocale(), rename _Py_wchar2char() to Py_EncodeLocale(), and document these functions.
Issue #21233: Add new C functions: PyMem_RawCalloc(), PyMem_Calloc(), PyObject_Calloc(), _PyObject_GC_Calloc(). bytes(int) is now using calloc() instead of malloc() for large objects which is faster and use less memory.
Issue #20942: PyImport_ImportFrozenModuleObject() no longer sets __file__ to match what importlib does; this affects _frozen_importlib as well as any module loaded using imp.init_frozen().
Documentation:
Issue #19548: Update the codecs module documentation to better cover the distinction between text encodings and other codecs, together with other clarifications. Patch by Martin Panter.
Issue #22394: Doc/Makefile now supports make venv PYTHON=../python to create a venv for generating the documentation, e.g., make html PYTHON=venv/bin/python3.
Issue #21514: The documentation of the json module now refers to new JSON RFC 7159 instead of obsoleted RFC 4627.
Issue #21777: The binary sequence methods on bytes and bytearray are now documented explicitly, rather than assuming users will be able to derive the expected behaviour from the behaviour of the corresponding str methods.
Issue #6916: undocument deprecated asynchat.fifo class.
Issue #17386: Expanded functionality of the Doc/make.bat script to make it much more comparable to Doc/Makefile.
Issue #21312: Update the thread_foobar.h template file to include newer threading APIs. Patch by Jack McCracken.
Issue #21043: Remove the recommendation for specific CA organizations and to mention the ability to load the OS certificates.
Issue #20765: Add missing documentation for PurePath.with_name() and PurePath.with_suffix().
Issue #19407: New package installation and distribution guides based on the Python Packaging Authority tools. Existing guides have been retained as legacy links from the distutils docs, as they still contain some required reference material for tool developers that isn’t recorded anywhere else.
Issue #19697: Document cases where __main__.__spec__ is None.
Tests:
Issue #18982: Add tests for CLI of the calendar module.
Issue #19548: Added some additional checks to test_codecs to ensure that statements in the updated documentation remain accurate. Patch by Martin Panter.
Issue #22838: All test_re tests now work with unittest test discovery.
Issue #22173: Update lib2to3 tests to use unittest test discovery.
Issue #16000: Convert test_curses to use unittest.
Issue #21456: Skip two tests in test_urllib2net.py if _ssl module not present. Patch by Remi Pointel.
Issue #20746: Fix test_pdb to run in refleak mode (-R). Patch by Xavier de Gaye.
Issue #22060: test_ctypes has been somewhat cleaned up and simplified; it now uses unittest test discovery to find its tests.
Issue #22104: regrtest.py no longer holds a reference to the suite of tests loaded from test modules that don’t define test_main().
Issue #22111: Assorted cleanups in test_imaplib. Patch by Milan Oberkirch.
Issue #22002: Added load_package_tests function to test.support and used it to implement/augment test discovery in test_asyncio, test_email, test_importlib, test_json, and test_tools.
Issue #21976: Fix test_ssl to accept LibreSSL version strings. Thanks to William Orr.
Issue #21918: Converted test_tools from a module to a package containing separate test files for each tested script.
Issue #9554: Use modern unittest features in test_argparse. Initial patch by Denver Coneybeare and Radu Voicilas.
Issue #20155: Changed HTTP method names in failing tests in test_httpservers so that packet filtering software (specifically Windows Base Filtering Engine) does not interfere with the transaction semantics expected by the tests.
Issue #19493: Refactored the ctypes test package to skip tests explicitly rather than silently.
Issue #18492: All resources are now allowed when tests are not run by regrtest.py.
Issue #21634: Fix pystone micro-benchmark: use floor division instead of true division to benchmark integers instead of floating point numbers. Set pystone version to 1.2. Patch written by Lennart Regebro.
Issue #21605: Added tests for Tkinter images.
Issue #21493: Added test for ntpath.expanduser(). Original patch by Claudiu Popa.
Issue #19925: Added tests for the spwd module. Original patch by Vajrasky Kok.
Issue #21522: Added Tkinter tests for Listbox.itemconfigure(), PanedWindow.paneconfigure(), and Menu.entryconfigure().
Issue #17756: Fix test_code test when run from the installed location.
Issue #17752: Fix distutils tests when run from the installed location.
Issue #18604: Consolidated checks for GUI availability. All platforms now at least check whether Tk can be instantiated when the GUI resource is requested.
Issue #21275: Fix a socket test on KFreeBSD.
Issue #21223: Pass test_site/test_startup_imports when some of the extensions are built as builtins.
Issue #20635: Added tests for Tk geometry managers.
Add test case for freeze.
Issue #20743: Fix a reference leak in test_tcl.
Issue #21097: Move test_namespace_pkgs into test_importlib.
Issue #21503: Use test_both() consistently in test_importlib.
Issue #20939: Avoid various network test failures due to new redirect of
Issue #20668: asyncio tests no longer rely on tests.txt file. (Patch by Vajrasky Kok)
Issue #21093: Prevent failures of ctypes test_macholib on OS X if a copy of libz exists in $HOME/lib or /usr/local/lib.
Issue #22770: Prevent some Tk segfaults on OS X when running gui tests.
Issue #23211: Workaround test_logging failure on some OS X 10.6 systems.
Issue #23345: Prevent test_ssl failures with large OpenSSL patch level values (like 0.9.8zc).
Tools/Demos:
Issue #22314: pydoc now works when the LINES environment variable is set.
Issue #22615: Argument Clinic now supports the “type” argument for the int converter. This permits using the int converter with enums and typedefs.
Issue #20076: The makelocalealias.py script no longer ignores UTF-8 mapping.
Issue #20079: The makelocalealias.py script now can parse the SUPPORTED file from glibc sources and supports command line options for source paths.
Issue #22201: Command-line interface of the zipfile module now correctly extracts ZIP files with directory entries. Patch by Ryan Wilson.
Issue #22120: For functions using an unsigned integer return converter, Argument Clinic now generates a cast to that type for the comparison to -1 in the generated code. (This supresses a compilation warning.)
Issue #18974: Tools/scripts/diff.py now uses argparse instead of optparse.
Issue #21906: Make Tools/scripts/md5sum.py work in Python 3. Patch by Zachary Ware.
Issue #21629: Fix Argument Clinic’s “–converters” feature.
Add support for yield from to 2to3.
Add support for the PEP 465 matrix multiplication operator to 2to3.
Issue #16047: Fix module exception list and __file__ handling in freeze. Patch by Meador Inge.
Issue #11824: Consider ABI tags in freeze. Patch by Meador Inge.
Issue #20535: PYTHONWARNING no longer affects the run_tests.py script. Patch by Arfrever Frehtes Taifersar Arahesis.
Windows:
Issue #23260: Update Windows installer
The bundled version of Tcl/Tk has been updated to 8.6.3. The most visible result of this change is the addition of new native file dialogs when running on Windows Vista or newer. See Tcl/Tk’s TIP 432 for more information. Also, this version of Tcl/Tk includes support for Windows 10.
Issue #17896: The Windows build scripts now expect external library sources to be in PCbuild\..\externals rather than PCbuild\..\...
Issue #17717: The Windows build scripts now use a copy of NASM pulled from svn.python.org to build OpenSSL.
Issue #21907: Improved the batch scripts provided for building Python.
Issue #2264

New in Python 2.7.9 (Dec 11, 2014)

New in Python 3.4.2 (Oct 8, 2014)

New in Python 2.7.8 (Jul 2, 2014)

Core and Builtins:
Issue #4346: In PyObject_CallMethod and PyObject_CallMethodObjArgs, don't overwrite the error set in PyObject_GetAttr.
Issue #21831: Avoid integer overflow when large sizes and offsets are given to the buffer type.
Issue #1856: Avoid crashes and lockups when daemon threads run while the interpreter is shutting down; instead, these threads are now killed when they try to take the GIL.
Issue #19656: Running Python with the -3 option now also warns about non-ascii bytes literals.
Issue #21642: If the conditional if-else expression, allow an integer written with no space between itself and the ``else`` keyword (e.g. ``True if 42else False``) to be valid syntax.
Issue #21523: Fix over-pessimistic computation of the stack effect of some opcodes in the compiler. This also fixes a quadratic compilation time issue noticeable when compiling code with a large number of "and" and "or" operators.
Library:
Issue #21652: Prevent mimetypes.type_map from containing unicode keys on Windows.
Issue #21729: Used the "with" statement in the dbm.dumb module to ensure files closing.
Issue #21672: Fix the behavior of ntpath.join on UNC-style paths.
Issue #19145: The times argument for itertools.repeat now handles negative values the same way for keyword arguments as it does for positional arguments.
Issue #21832: Require named tuple inputs to be exact strings.
Issue #8343: Named group error messages in the re module did not show the name of the erroneous group.
Issue #21491: SocketServer: Fix a race condition in child processes reaping.
Issue #21635: The difflib SequenceMatcher.get_matching_blocks() method cache didn't match the actual result. The former was a list of tuples and the latter was a list of named tuples.
Issue #21722: The distutils "upload" command now exits with a non-zero return code when uploading fails. Patch by Martin Dengler.
Issue #21766: Prevent a security hole in CGIHTTPServer by URL unquoting paths before checking for a CGI script at that path.
Issue #21310: Fixed possible resource leak in failed open().
Issue #21304: Backport the key derivation function hashlib.pbkdf2_hmac from Python 3 per PEP 466.
Issue #11709: Fix the pydoc.help function to not fail when sys.stdin is not a valid file.
Issue #13223: Fix pydoc.writedoc so that the HTML documentation for methods that use 'self' in the example code is generated correctly.
Issue #21552: Fixed possible integer overflow of too long string lengths in the tkinter module on 64-bit platforms.
Issue #14315: The zipfile module now ignores extra fields in the central directory that are too short to be parsed instead of letting a struct.unpack error bubble up as this "bad data" appears in many real world zip files in the wild and is ignored by other zip tools.
Issue #21402: Tkinter.ttk now works when default root window is not set.
Issue #10203: sqlite3.Row now truly supports sequence protocol. In particulr it supports reverse() and negative indices. Original patch by Claudiu Popa.
Issue #8743: Fix interoperability between set objects and the collections.Set() abstract base class.
Issue #21481: Argparse equality and inequality tests now return NotImplemented when comparing to an unknown type.
IDLE:
Issue #21686: add unittest for HyperParser. Original patch by Saimadhav Heblikar.
Issue #12387: Add missing upper(lower)case versions of default Windows key bindings for Idle so Caps Lock does not disable them. Patch by Roger Serwy.
Issue #21695: Closing a Find-in-files output window while the search is still in progress no longer closes Idle.
Issue #18910: Add unittest for textView. Patch by Phil Webster.
Issue #18292: Add unittest for AutoExpand. Patch by Saihadhav Heblikar.
Issue #18409: Add unittest for AutoComplete. Patch by Phil Webster.
Tests:
Issue #20155: Changed HTTP method names in failing tests in test_httpservers so that packet filtering software (specifically Windows Base Filtering Engine) does not interfere with the transaction semantics expected by the tests.
Issue #19493: Refactored the ctypes test package to skip tests explicitly rather than silently.
Issue #18492: All resources are now allowed when tests are not run by regrtest.py.
Issue #21605: Added tests for Tkinter images.
Issue #21493: Added test for ntpath.expanduser(). Original patch by Claudiu Popa.
Issue #19925: Added tests for the spwd module. Original patch by Vajrasky Kok.
Issue #13355: random.triangular() no longer fails with a ZeroDivisionError when low equals high.
Issue #21522: Added Tkinter tests for Listbox.itemconfigure(), PanedWindow.paneconfigure(), and Menu.entryconfigure().
Issue #20635: Added tests for Tk geometry managers.
Windows:
Issue #21671, CVE-2014-0224: The bundled version of OpenSSL has been updated to 1.0.1h.

New in Python 2.7.7 (Jun 9, 2014)

New in Python 3.4.1 (May 19, 2014)

New in Python 3.4.0 (Mar 18, 2014)

New in Python 3.4.0 RC3 (Mar 10, 2014)

New in Python 3.3.5 RC1 (Feb 25, 2014)

Core and Builtins:
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 #20588: Make Python-ast.c C89 compliant.
Issue #20437: Fixed 21 potential bugs when deleting objects references.
Issue #20538: UTF-7 incremental decoder produced inconsistant string when input was truncated in BASE64 section.
Library:
Issue #20635: Fixed grid_columnconfigure() and grid_rowconfigure() methods of Tkinter widgets to work in wantobjects=True mode.
Issue #19612: On Windows, subprocess.Popen.communicate() now ignores OSError(22, ‘Invalid argument’) when writing input data into stdin, whereas the process already exited.
Issue #6815: os.path.expandvars() now supports non-ASCII environment variables names and values.
Issue #17671: Fixed a crash when use non-initialized io.BufferedRWPair. Based on patch by Stephen Tu.
Issue #8478: Untokenizer.compat processes first token from iterator input. Patch based on lines from Georg Brandl, Eric Snow, and Gareth Rees.
Issue #20594: Avoid name clash with the libc function posix_close.
Issue #19856: shutil.move() failed to move a directory to other directory on Windows if source name ends with os.altsep.
Issue #14983: email.generator now always adds a line end after each MIME boundary marker, instead of doing so only when there is an epilogue. This fixes an RFC compliance bug and solves an issue with signed MIME parts.
Issue #20540: Fix a performance regression (vs. Python 3.2) when layering a multiprocessing Connection over a TCP socket. For small payloads, Nagle’s algorithm would introduce idle delays before the entire transmission of a message.
Issue #16983: the new email header parsing code will now decode encoded words that are (incorrectly) surrounded by quotes, and register a defect.
Issue #19772: email.generator no longer mutates the message object when doing a down-transform from 8bit to 7bit CTEs.
Issue #18805: the netmask/hostmask parsing in ipaddress now more reliably filters out illegal values and correctly allows any valid prefix length.
Issue #17369: get_filename was raising an exception if the filename parameter’s RFC2231 encoding was broken in certain ways. This was a regression relative to python2.
Issue #20013: Some imap servers disconnect if the current mailbox is deleted, and imaplib did not handle that case gracefully. Now it handles the ‘bye’ correctly.
Issue #19920: TarFile.list() no longer fails when outputs a listing containing non-encodable characters. Based on patch by Vajrasky Kok.
Issue #20515: Fix NULL pointer dereference introduced by issue #20368.
Issue #19186: Restore namespacing of expat symbols inside the pyexpat module.
Issue #20426: When passing the re.DEBUG flag, re.compile() displays the debug output every time it is called, regardless of the compilation cache.
Issue #20368: The null character now correctly passed from Tcl to Python. Improved error handling in variables-related commands.
Issue #20435: Fix _pyio.StringIO.getvalue() to take into account newline translation settings.
Issue #20288: fix handling of invalid numeric charrefs in HTMLParser.
Issue #20424: Python implementation of io.StringIO now supports lone surrogates.
Issue #19456: ntpath.join() now joins relative paths correctly when a drive is present.
Issue #19077: tempfile.TemporaryDirectory cleanup is now most likely successful when called during nulling out of modules during shutdown. Misleading exception no longer raised when resource warning is emitted during shutdown.
Issue #20367: Fix behavior of concurrent.futures.as_completed() for duplicate arguments. Patch by Glenn Langford.
Issue #8260: The read(), readline() and readlines() methods of codecs.StreamReader returned incomplete data when were called after readline() or read(size). Based on patch by Amaury Forgeot d’Arc.
IDLE:
Issue #20406: Use Python application icons for Idle window title bars. Patch mostly by Serhiy Storchaka.
Update the python.gif icon for the Idle classbrowser and pathbowser from the old green snake to the new new blue and yellow snakes.
Issue #17721: Remove non-functional configuration dialog help button until we make it actually gives some help when clicked. Patch by Guilherme Simões.
Tests:
Issue #20743: Fix a reference leak in test_tcl.
Issue #20510: Rewrote test_exit in test_sys to match existing comments, use modern unittest features, and use helpers from test.script_helper instead of using subprocess directly. Patch by Gareth Rees.
Issue #20532: Tests which use _testcapi are now marked as CPython only.
Issue #19920: Added tests for TarFile.list(). Based on patch by Vajrasky Kok.
Issue #19990: Added tests for the imghdr module. Based on patch by Claudiu Popa.
Issue #20474: Fix test_socket “unexpected success” failures on OS X 10.7+.
Issue #20605: Make test_socket getaddrinfo OS X segfault test more robust.
Documentation:
Issue #20488: Importlib is no longer an implementation of import, it’s the implementation.
Build:
Issue #20221: Removed conflicting (or circular) hypot definition when compiled with VS 2010 or above. Initial patch by Tabrez Mohammed.
Issue #20609: Restored the ability to build 64-bit Windows binaries on 32-bit Windows, which was broken by the change in issue #19788.
Tools/Demos:
Issue #20535: PYTHONWARNING no longer affects the run_tests.py script. Patch by Arfrever Frehtes Taifersar Arahesis.

New in Python 3.4.0 RC1 (Jan 28, 2014)

Core and Builtins
Issue #17825: Cursor “^” is correctly positioned for SyntaxError and IndentationError.
Issue #2382: SyntaxError cursor “^” is now written at correct position in most cases when multibyte characters are in line (before “^”). This still not works correctly with wide East Asian characters.
Issue #18960: The first line of Python script could be executed twice when the source encoding was specified on the second line. Now the source encoding declaration on the second line isn’t effective if the first line contains anything except a comment. ‘python -x’ works now again with files with the source encoding declarations, and can be used to make Python batch files on Windows.
Issue #19081: When a zipimport .zip file in sys.path being imported from is modified during the lifetime of the Python process after zipimport has already cached the zip’s table of contents we detect this and recover rather than read bad data from the .zip (causing odd import errors).
Issue #17432: Drop UCS2 from names of Unicode functions in python3.def.
Issue #19969: PyBytes_FromFormatV() now raises an OverflowError if “%c” argument is not in range [0; 255].
Issue #14432: Generator now clears the borrowed reference to the thread state. Fix a crash when a generator is created in a C thread that is destroyed while the generator is still used. The issue was that a generator contains a frame, and the frame kept a reference to the Python state of the destroyed C thread. The crash occurs when a trace function is setup.
Issue #19932: Fix typo in import.h, missing whitespaces in function prototypes.
Issue #19729: In str.format(), fix recursive expansion in format spec.
Issue #19638: Fix possible crash / undefined behaviour from huge (more than 2 billion characters) input strings in _Py_dg_strtod.
Library
Issue #8260: The read(), readline() and readlines() methods of codecs.StreamReader returned incomplete data when were called after readline() or read(size). Based on patch by Amaury Forgeot d’Arc.
Issue #20317: ExitStack.__exit__ could create a self-referential loop if an exception raised by a cleanup operation already had its context set correctly (for example, by the @contextmanager decorator). The infinite loop this caused is now avoided by checking if the expected context is already set before trying to fix it.
Issue #20374: Fix build with GNU readline >= 6.3.
Issue #20262: Warnings are raised now when duplicate names are added in the ZIP file or too long ZIP file comment is truncated.
Issue #18574: Added missing newline in 100-Continue reply from http.server.BaseHTTPRequestHandler. Patch by Nikolaus Rath.
Issue #20270: urllib.urlparse now supports empty ports.
Issue #20243: TarFile no longer raise ReadError when opened in write mode.
Issue #20238: TarFile opened with external fileobj and “w:gz” mode didn’t write complete output on close.
Issue #20245: The open functions in the tarfile module now correctly handle empty mode.
Issue #20242: Fixed basicConfig() format strings for the alternative formatting styles. Thanks to kespindler for the bug report and patch.
Issue #20246: Fix buffer overflow in socket.recvfrom_into.
Issues #20206 and #5803: Fix edge case in email.quoprimime.encode where it truncated lines ending in a character needing encoding but no newline by using a more efficient algorithm that doesn’t have the bug.
Issue #19082: Working xmlrpc.server and xmlrpc.client examples. Both in modules and in documentation. Initial patch contributed by Vajrasky Kok.
Issue #20138: The wsgiref.application_uri() and wsgiref.request_uri() functions now conform to PEP 3333 when handle non-ASCII URLs.
Issue #19097: Raise the correct Exception when cgi.FieldStorage is given an invalid fileobj.
Issue #20217: Fix build in SCHED_SPORADIC is defined.
Issue #13107: argparse and optparse no longer raises an exception when output a help on environment with too small COLUMNS. Based on patch by Elazar Gershuni.
Issue #20207: Always disable SSLv2 except when PROTOCOL_SSLv2 is explicitly asked for.
Issue #18960: The tokenize module now ignore the source encoding declaration on the second line if the first line contains anything except a comment.
Issue #20078: Reading malformed zipfiles no longer hangs with 100% CPU consumption.
Issue #20113: os.readv() and os.writev() now raise an OSError exception on error instead of returning -1.
Issue #20072: Fixed multiple errors in tkinter with wantobjects is False.
Issue #20108: Avoid parameter name clash in inspect.getcallargs().
Issue #12692: Backport the fix for ResourceWarning in test_urllib2net. This also helps in closing the socket when Connection Close header is not sent.
Issue #19422: Explicitly disallow non-SOCK_STREAM sockets in the ssl module, rather than silently let them emit clear text data.
Issue #18116: getpass was always getting an error when testing /dev/tty, and thus was always falling back to stdin, and would then raise an exception if stdin could not be used (such as /dev/null). It also leaked an open file. All of these issues are now fixed.
Issue #20027: Fixed locale aliases for devanagari locales.
Issue #20067: Tkinter variables now work when wantobjects is false.
Issue #19020: Tkinter now uses splitlist() instead of split() in configure methods.
Fix TypeError on “setup.py upload –show-response”.
Issue #12226: HTTPS is now used by default when connecting to PyPI.
Issue #20045: Fix “setup.py register –list-classifiers”.
Issue #18879: When a method is looked up on a temporary file, avoid closing the file before the method is possibly called.
Issue #20034: Updated alias mapping to most recent locale.alias file from X.org distribution using makelocalealias.py.
Issue #5815: Fixed support for locales with modifiers. Fixed support for locale encodings with hyphens.
Issue #20026: Fix the sqlite module to handle correctly invalid isolation level (wrong type).
Issue #18829: csv.Dialect() now checks type for delimiter, escapechar and quotechar fields. Original patch by Vajrasky Kok.
Issue #19855: uuid.getnode() on Unix now looks on the PATH for the executables used to find the mac address, with /sbin and /usr/sbin as fallbacks.
Issue #20007: HTTPResponse.read(0) no more prematurely closes connection. Original patch by Simon Sapin.
Issue #19912: Fixed numerous bugs in ntpath.splitunc().
Issue #19911: ntpath.splitdrive() now correctly processes the ‘I’ character (U+0130, LATIN CAPITAL LETTER I WITH DOT ABOVE).
Issue #19532: python -m compileall with no filename/directory arguments now respects the -f and -q flags instead of ignoring them.
Issue #19623: Fixed writing to unseekable files in the aifc module.
Issue #17919: select.poll.register() again works with poll.POLLNVAL on AIX. Fixed integer overflow in the eventmask parameter.
Issue #19063: if a Charset’s body_encoding was set to None, the email package would generate a message claiming the Content-Transfer-Encoding was 7bit, and produce garbage output for the content. This now works. A couple of other set_payload mishandlings of non-ASCII are also fixed.
Issue #17200: telnetlib’s read_until and expect timeout was broken by the fix to Issue #14635 in Python 3.3.0 to be interpreted as milliseconds instead of seconds when the platform supports select.poll (ie: everywhere). It is now treated as seconds once again.
Issue #17429: platform.linux_distribution() now decodes files from the UTF-8 encoding with the surrogateescape error handler, instead of decoding from the locale encoding in strict mode. It fixes the function on Fedora 19 which is probably the first major distribution release with a non-ASCII name. Patch written by Toshio Kuratomi.
Issue #19929: Call os.read with 32768 within subprocess.Popen.communicate rather than 4096 for efficiency. A microbenchmark shows Linux and OS X both using ~50% less cpu time this way.
Issue #19506: Use a memoryview to avoid a data copy when piping data to stdin within subprocess.Popen.communicate. 5-10% less cpu usage.
Issue #19839: Fix regression in bz2 module’s handling of non-bzip2 data at EOF, and analogous bug in lzma module.
Issue #19138: doctest’s IGNORE_EXCEPTION_DETAIL now allows a match when no exception detail exists (no colon following the exception’s name, or a colon does follow but no text follows the colon).
Issue #19834: Support unpickling of exceptions pickled by Python 2.
Issue #15798: Fixed subprocess.Popen() to no longer fail if file descriptor 0, 1 or 2 is closed.
Issue #19088: Fixed incorrect caching of the copyreg module in object.__reduce__() and object.__reduce_ex__().
Fixed _pickle.Unpickler to not fail when loading empty strings as persistent IDs.
Issue #11480: Fixed copy.copy to work with classes with custom metaclasses. Patch by Daniel Urban.
Issue #6477: Added support for pickling the types of built-in singletons (i.e., Ellipsis, NotImplemented, None).
Issue #11508: Fixed uuid.getnode() and uuid.uuid1() on environment with virtual interface. Original patch by Kent Frazier.
Issue #11489: JSON decoder now accepts lone surrogates.
Issue #19545: Avoid chained exceptions while passing stray % to time.strptime(). Initial patch by Claudiu Popa.
Issue #19633: Fixed writing not compressed 16- and 32-bit wave files on big-endian platforms.
Issue #19449: in csv’s writerow, handle non-string keys when generating the error message that certain keys are not in the ‘fieldnames’ list.
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 #19523: Closed FileHandler leak which occurred when delay was set.
Issue #13674: Prevented time.strftime from crashing on Windows when given a year before 1900 and a format of %y.
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 #1575020: Fixed support of 24-bit wave files on big-endian platforms.
Issue #19480: HTMLParser now accepts all valid start-tag names as defined by the HTML5 standard.
Issue #6157: Fixed tkinter.Text.debug(). Original patch by Guilherme Polo.
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 #10197: Rework subprocess.get[status]output to use subprocess functionality and thus to work on Windows. Patch by Nick Coghlan.
Issue #19286: Directories in package_data are no longer added to the filelist, preventing failure outlined in the ticket.
IDLE
–Issue #17390: Add Python version to Idle editor window title bar.
Original patches by Edmond Burnett and Kent Johnson.
Issue #18960: IDLE now ignores the source encoding declaration on the second line if the first line contains anything except a comment.
Issue #20058: sys.stdin.readline() in IDLE now always returns only one line.
Issue #19481: print() of string subclass instance in IDLE no longer hangs.
Issue #18270: Prevent possible IDLE AttributeError on OS X when no initial shell window is present.
Tests
Issue #19804: The test_find_mac test in test_uuid is now skipped if the ifconfig executable is not available.
Issue #19886: Use better estimated memory requirements for bigmem tests.
Issue #20055: Fix test_shutil under Windows with symlink privileges held. Patch by Vajrasky Kok.
Issue #19938: Re-enabled test_bug_1333982 in test_dis, which had been disabled since 3.0 due to the changes in listcomp handling.
Issue #19320: test_tcl no longer fails when wantobjects is false.
Issue #19683: Removed empty tests from test_minidom. Patch by Ajitesh Gupta.
Issue #19919: Fix flaky SSL test. connect_ex() sometimes returns EWOULDBLOCK on Windows or VMs hosted on Windows.
Issue #19912: Added tests for ntpath.splitunc().
Issue #19828: Fixed test_site when the whole suite is run with -S.
Issue #19928: Implemented a test for repr() of cell objects.
Issue #19535: Fixed test_docxmlrpc when python is run with -OO.
Issue #19926: Removed unneeded test_main from test_abstract_numbers. Patch by Vajrasky Kok.
Issue #19595, #19987: Re-enabled a long-disabled test in test_winsound.
Issue #19588: Fixed tests in test_random that were silently skipped most of the time. Patch by Julian Gindi.
Issue #19596: Set untestable tests in test_importlib to None to avoid reporting success on empty tests.
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 within a unittest TestCase.
Issue #18702, 19572: All skipped tests now reported as skipped.
Issue #19085: Added basic tests for all tkinter widget options.
Documentation
Issue #20265: Updated some parts of the Using Windows document.
Issue #20266: Updated some parts of the Windows FAQ.
Issue #20255: Updated the about and bugs pages.
Issue #20253: Fixed a typo in the ipaddress docs that advertised an illegal attribute name. Found by INADA Naoki.
Issue #19963: Document that importlib.import_module() no longer requires importing parent packages separately.
Issue #18840: Introduce the json module in the tutorial, and de-emphasize the pickle module.
Issue #19845: Updated the Compiling Python on Windows section.
Issue #19795: Improved markup of True/False constants.
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
Issue #19788: kill_python(_d).exe is now run as a PreBuildEvent on the pythoncore sub-project. This should prevent build errors due a previous build’s python(_d).exe still running.
Add workaround for VS 2010 nmake clean issue. VS 2010 doesn’t set up PATH for nmake.exe correctly.
Tools/Demos
Issue #19936: Added executable bits or shebang lines to Python scripts which requires them. Disable executable bits and shebang lines in test and benchmark files in order to prevent using a random system python, and in source files of modules which don’t provide command line interface. Fixed shebang line to use python3 executable in the unittestgui script.
Issue #18960: 2to3 and the findnocoding.py script now ignore the source encoding declaration on the second line if the first line contains anything except a comment.