3.5.txt

(Contributed by Victor Stinner in bpo-18395.)

A new "PyCodec_NameReplaceErrors()" function to replace the unicode
encode error with "\N{...}" escapes. (Contributed by Serhiy Storchaka
in bpo-19676.)

A new "PyErr_FormatV()" function similar to "PyErr_Format()", but
accepts a "va_list" argument. (Contributed by Antoine Pitrou in
bpo-18711.)

A new "PyExc_RecursionError" exception. (Contributed by Georg Brandl
in bpo-19235.)

New "PyModule_FromDefAndSpec()", "PyModule_FromDefAndSpec2()", and
"PyModule_ExecDef()" functions introduced by **PEP 489** -- multi-
phase extension module initialization. (Contributed by Petr Viktorin
in bpo-24268.)

New "PyNumber_MatrixMultiply()" and "PyNumber_InPlaceMatrixMultiply()"
functions to perform matrix multiplication. (Contributed by Benjamin
Peterson in bpo-21176.  See also **PEP 465** for details.)

The "PyTypeObject.tp_finalize" slot is now part of the stable ABI.

Windows builds now require Microsoft Visual C++ 14.0, which is
available as part of Visual Studio 2015.

Extension modules now include a platform information tag in their
filename on some platforms (the tag is optional, and CPython will
import extensions without it, although if the tag is present and
mismatched, the extension won't be loaded):

* On Linux, extension module filenames end with
  ".cpython-<major><minor>m-<architecture>-<os>.pyd":

  * "<major>" is the major number of the Python version; for Python
    3.5 this is "3".

  * "<minor>" is the minor number of the Python version; for Python
    3.5 this is "5".

  * "<architecture>" is the hardware architecture the extension module
    was built to run on. It's most commonly either "i386" for 32-bit
    Intel platforms or "x86_64" for 64-bit Intel (and AMD) platforms.

  * "<os>" is always "linux-gnu", except for extensions built to talk
    to the 32-bit ABI on 64-bit platforms, in which case it is "linux-
    gnu32" (and "<architecture>" will be "x86_64").

* On Windows, extension module filenames end with
  "<debug>.cp<major><minor>-<platform>.pyd":

  * "<major>" is the major number of the Python version; for Python
    3.5 this is "3".

  * "<minor>" is the minor number of the Python version; for Python
    3.5 this is "5".

  * "<platform>" is the platform the extension module was built for,
    either "win32" for Win32, "win_amd64" for Win64, "win_ia64" for
    Windows Itanium 64, and "win_arm" for Windows on ARM.

  * If built in debug mode, "<debug>" will be "_d", otherwise it will
    be blank.

* On OS X platforms, extension module filenames now end with
  "-darwin.so".

* On all other platforms, extension module filenames are the same as
  they were with Python 3.4.


Deprecated
==========


New Keywords
------------

"async" and "await" are not recommended to be used as variable, class,
function or module names.  Introduced by **PEP 492** in Python 3.5,
they will become proper keywords in Python 3.7.


Deprecated Python Behavior
--------------------------

Raising the "StopIteration" exception inside a generator will now
generate a silent "PendingDeprecationWarning", which will become a
non-silent deprecation warning in Python 3.6 and will trigger a
"RuntimeError" in Python 3.7. See PEP 479: Change StopIteration
handling inside generators for details.


Unsupported Operating Systems
-----------------------------

Windows XP is no longer supported by Microsoft, thus, per **PEP 11**,
CPython 3.5 is no longer officially supported on this OS.


Deprecated Python modules, functions and methods
------------------------------------------------

The "formatter" module has now graduated to full deprecation and is
still slated for removal in Python 3.6.

The "asyncio.async()" function is deprecated in favor of
"ensure_future()".

The "smtpd" module has in the past always decoded the DATA portion of
email messages using the "utf-8" codec.  This can now be controlled by
the new *decode_data* keyword to "SMTPServer".  The default value is
"True", but this default is deprecated.  Specify the *decode_data*
keyword with an appropriate value to avoid the deprecation warning.

Directly assigning values to the "key", "value" and "coded_value" of
"http.cookies.Morsel" objects is deprecated.  Use the "set()" method
instead.  In addition, the undocumented *LegalChars* parameter of
"set()" is deprecated, and is now ignored.

Passing a format string as keyword argument *format_string* to the
"format()" method of the "string.Formatter" class has been deprecated.
(Contributed by Serhiy Storchaka in bpo-23671.)

The "platform.dist()" and "platform.linux_distribution()" functions
are now deprecated.  Linux distributions use too many different ways
of describing themselves, so the functionality is left to a package.
(Contributed by Vajrasky Kok and Berker Peksag in bpo-1322.)

The previously undocumented "from_function" and "from_builtin" methods
of "inspect.Signature" are deprecated.  Use the new
"Signature.from_callable()" method instead. (Contributed by Yury
Selivanov in bpo-24248.)

The "inspect.getargspec()" function is deprecated and scheduled to be
removed in Python 3.6.  (See bpo-20438 for details.)

The "inspect" "getfullargspec()", "getcallargs()", and
"formatargspec()" functions are deprecated in favor of the
"inspect.signature()" API. (Contributed by Yury Selivanov in
bpo-20438.)

"getargvalues()" and "formatargvalues()" functions were inadvertently
marked as deprecated with the release of Python 3.5.0.

Use of "re.LOCALE" flag with str patterns or "re.ASCII" is now
deprecated.  (Contributed by Serhiy Storchaka in bpo-22407.)

Use of unrecognized special sequences consisting of "'\'" and an ASCII
letter in regular expression patterns and replacement patterns now
raises a deprecation warning and will be forbidden in Python 3.6.
(Contributed by Serhiy Storchaka in bpo-23622.)

The undocumented and unofficial *use_load_tests* default argument of
the "unittest.TestLoader.loadTestsFromModule()" method now is
deprecated and ignored. (Contributed by Robert Collins and Barry A.
Warsaw in bpo-16662.)


Removed
=======


API and Feature Removals
------------------------

The following obsolete and previously deprecated APIs and features
have been removed:

* The "__version__" attribute has been dropped from the email package.
  The email code hasn't been shipped separately from the stdlib for a
  long time, and the "__version__" string was not updated in the last
  few releases.

* The internal "Netrc" class in the "ftplib" module was deprecated in
  3.4, and has now been removed. (Contributed by Matt Chaput in
  bpo-6623.)

* The concept of ".pyo" files has been removed.

* The JoinableQueue class in the provisional "asyncio" module was
  deprecated in 3.4.4 and is now removed. (Contributed by A. Jesse
  Jiryu Davis in bpo-23464.)


Porting to Python 3.5
=====================

This section lists previously described changes and other bugfixes
that may require changes to your code.


Changes in Python behavior
--------------------------

* Due to an oversight, earlier Python versions erroneously accepted
  the following syntax:

     f(1 for x in [1], *args)
     f(1 for x in [1], **kwargs)

  Python 3.5 now correctly raises a "SyntaxError", as generator
  expressions must be put in parentheses if not a sole argument to a
  function.


Changes in the Python API
-------------------------

* **PEP 475**: System calls are now retried when interrupted by a
  signal instead of raising "InterruptedError" if the Python signal
  handler does not raise an exception.

* Before Python 3.5, a "datetime.time" object was considered to be
  false if it represented midnight in UTC.  This behavior was
  considered obscure and error-prone and has been removed in Python
  3.5.  See bpo-13936 for full details.

* The "ssl.SSLSocket.send()" method now raises either
  "ssl.SSLWantReadError" or "ssl.SSLWantWriteError" on a non-blocking
  socket if the operation would block.  Previously, it would return
  "0".  (Contributed by Nikolaus Rath in bpo-20951.)

* The "__name__" attribute of generators is now set from the function
  name, instead of being set from the code name. Use
  "gen.gi_code.co_name" to retrieve the code name. Generators also
  have a new "__qualname__" attribute, the qualified name, which is
  now used for the representation of a generator ("repr(gen)").
  (Contributed by Victor Stinner in bpo-21205.)

* The deprecated "strict" mode and argument of "HTMLParser",
  "HTMLParser.error()", and the "HTMLParserError" exception have been
  removed.  (Contributed by Ezio Melotti in bpo-15114.) The
  *convert_charrefs* argument of "HTMLParser" is now "True" by
  default.  (Contributed by Berker Peksag in bpo-21047.)

* Although it is not formally part of the API, it is worth noting for
  porting purposes (ie: fixing tests) that error messages that were
  previously of the form "'sometype' does not support the buffer
  protocol" are now of the form "a *bytes-like object* is required,
  not 'sometype'". (Contributed by Ezio Melotti in bpo-16518.)

* If the current directory is set to a directory that no longer exists
  then "FileNotFoundError" will no longer be raised and instead
  "find_spec()" will return "None" **without** caching "None" in
  "sys.path_importer_cache", which is different than the typical case
  (bpo-22834).

* HTTP status code and messages from "http.client" and "http.server"
  were refactored into a common "HTTPStatus" enum.  The values in
  "http.client" and "http.server" remain available for backwards
  compatibility.  (Contributed by Demian Brecht in bpo-21793.)

* When an import loader defines
  "importlib.machinery.Loader.exec_module()" it is now expected to
  also define "create_module()" (raises a "DeprecationWarning" now,
  will be an error in Python 3.6). If the loader inherits from
  "importlib.abc.Loader" then there is nothing to do, else simply
  define "create_module()" to return "None".  (Contributed by Brett
  Cannon in bpo-23014.)

* The "re.split()" function always ignored empty pattern matches, so
  the ""x*"" pattern worked the same as ""x+"", and the ""\b"" pattern
  never worked.  Now "re.split()" raises a warning if the pattern
  could match an empty string.  For compatibility, use patterns that
  never match an empty string (e.g. ""x+"" instead of ""x*"").
  Patterns that could only match an empty string (such as ""\b"") now
  raise an error. (Contributed by Serhiy Storchaka in bpo-22818.)

* The "http.cookies.Morsel" dict-like interface has been made self
  consistent:  morsel comparison now takes the "key" and "value" into
  account, "copy()" now results in a "Morsel" instance rather than a
  "dict", and "update()" will now raise an exception if any of the
  keys in the update dictionary are invalid.  In addition, the
  undocumented *LegalChars* parameter of "set()" is deprecated and is
  now ignored.  (Contributed by Demian Brecht in bpo-2211.)

* **PEP 488** has removed ".pyo" files from Python and introduced the
  optional "opt-" tag in ".pyc" file names. The
  "importlib.util.cache_from_source()" has gained an *optimization*
  parameter to help control the "opt-" tag. Because of this, the
  *debug_override* parameter of the function is now deprecated. *.pyo*
  files are also no longer supported as a file argument to the Python
  interpreter and thus serve no purpose when distributed on their own
  (i.e. sourceless code distribution). Due to the fact that the magic
  number for bytecode has changed in Python 3.5, all old *.pyo* files
  from previous versions of Python are invalid regardless of this PEP.

* The "socket" module now exports the "CAN_RAW_FD_FRAMES" constant on
  linux 3.6 and greater.

* The "ssl.cert_time_to_seconds()" function now interprets the input
  time as UTC and not as local time, per **RFC 5280**.  Additionally,
  the return value is always an "int". (Contributed by Akira Li in
  bpo-19940.)

* The "pygettext.py" Tool now uses the standard +NNNN format for
  timezones in the POT-Creation-Date header.

* The "smtplib" module now uses "sys.stderr" instead of the previous
  module-level "stderr" variable for debug output.  If your (test)
  program depends on patching the module-level variable to capture the
  debug output, you will need to update it to capture sys.stderr
  instead.

* The "str.startswith()" and "str.endswith()" methods no longer return
  "True" when finding the empty string and the indexes are completely
  out of range.  (Contributed by Serhiy Storchaka in bpo-24284.)

* The "inspect.getdoc()" function now returns documentation strings
  inherited from base classes.  Documentation strings no longer need
  to be duplicated if the inherited documentation is appropriate.  To
  suppress an inherited string, an empty string must be specified (or
  the documentation may be filled in).  This change affects the output
  of the "pydoc" module and the "help()" function. (Contributed by
  Serhiy Storchaka in bpo-15582.)

* Nested "functools.partial()" calls are now flattened.  If you were
  relying on the previous behavior, you can now either add an
  attribute to a "functools.partial()" object or you can create a
  subclass of "functools.partial()". (Contributed by Alexander
  Belopolsky in bpo-7830.)


Changes in the C API
--------------------

* The undocumented "format" member of the (non-public)
  "PyMemoryViewObject" structure has been removed. All extensions
  relying on the relevant parts in "memoryobject.h" must be rebuilt.

* The "PyMemAllocator" structure was renamed to "PyMemAllocatorEx" and
  a new "calloc" field was added.

* Removed non-documented macro "PyObject_REPR" which leaked
  references. Use format character "%R" in
  "PyUnicode_FromFormat()"-like functions to format the "repr()" of
  the object. (Contributed by Serhiy Storchaka in bpo-22453.)

* Because the lack of the "__module__" attribute breaks pickling and
  introspection, a deprecation warning is now raised for builtin types
  without the "__module__" attribute.  This would be an AttributeError
  in the future. (Contributed by Serhiy Storchaka in bpo-20204.)

* As part of the **PEP 492** implementation, the "tp_reserved" slot of
  "PyTypeObject" was replaced with a "tp_as_async" slot.  Refer to
  Coroutine Objects for new types, structures and functions.


Notable changes in Python 3.5.4
===============================


New "make regen-all" build target
---------------------------------

To simplify cross-compilation, and to ensure that CPython can reliably
be compiled without requiring an existing version of Python to already
be available, the autotools-based build system no longer attempts to
implicitly recompile generated files based on file modification times.

Instead, a new "make regen-all" command has been added to force
regeneration of these files when desired (e.g. after an initial
version of Python has already been built based on the pregenerated
versions).

More selective regeneration targets are also defined - see
Makefile.pre.in for details.

(Contributed by Victor Stinner in bpo-23404.)

New in version 3.5.4.


Removal of "make touch" build target
------------------------------------

The "make touch" build target previously used to request implicit
regeneration of generated files by updating their modification times
has been removed.

It has been replaced by the new "make regen-all" target.

(Contributed by Victor Stinner in bpo-23404.)

Changed in version 3.5.4.