[Python-checkins] r66091 - python/trunk/Doc/whatsnew/2.6.rst
andrew.kuchling
python-checkins at python.org
Sun Aug 31 17:41:48 CEST 2008
Author: andrew.kuchling
Date: Sun Aug 31 17:41:48 2008
New Revision: 66091
Log:
Last batch of edits; remove the 'other changes' section
Modified:
python/trunk/Doc/whatsnew/2.6.rst
Modified: python/trunk/Doc/whatsnew/2.6.rst
==============================================================================
--- python/trunk/Doc/whatsnew/2.6.rst (original)
+++ python/trunk/Doc/whatsnew/2.6.rst Sun Aug 31 17:41:48 2008
@@ -67,6 +67,11 @@
there aren't many new features that aren't related to Python 3.0 in
some way.
+Python 2.6 also sees a number of improvements and bugfixes throughout
+the source. A search through the change logs finds there were XXX
+patches applied and YYY bugs fixed between Python 2.5 and 2.6. Both
+figures are likely to be underestimates.
+
This article doesn't attempt to provide a complete specification of
the new features, but instead provides a convenient overview. For
full details, you should refer to the documentation for Python 2.6. If
@@ -2503,7 +2508,7 @@
:meth:`activeCount` method is renamed to :meth:`active_count`. The
2.6 version of the module supports the same properties and renamed
methods, but doesn't remove the old methods. (Carried out by
- various people, most notably Benjamin Peterson.)
+ several people, most notably Benjamin Peterson.)
The :mod:`threading` module's :class:`Thread` objects
gained an :attr:`ident` property that returns the thread's
@@ -2619,11 +2624,12 @@
The :mod:`ast` module
----------------------
-The :mod:`ast` module provides an Abstract Syntax Tree representation
-of Python code. For Python 2.6, Armin Ronacher contributed a set of
-helper functions that perform various common tasks. These will be useful
-for HTML templating packages, code analyzers, and similar tools that
-process Python code.
+The :mod:`ast` module provides an Abstract Syntax Tree
+representation of Python code, and Armin Ronacher
+contributed a set of helper functions that perform a variety of
+common tasks. These will be useful for HTML templating
+packages, code analyzers, and similar tools that process
+Python code.
The :func:`parse` function takes an expression and returns an AST.
The :func:`dump` function outputs a representation of a tree, suitable
@@ -2639,28 +2645,46 @@
""")
print ast.dump(t)
-This outputs::
+This outputs a deeply nested tree::
- Module(body=[Assign(targets=[Name(id='d', ctx=Store())],
- value=Dict(keys=[], values=[])), For(target=Name(id='i',
- ctx=Store()), iter=Str(s='abcdefghijklm'),
- body=[Assign(targets=[Subscript(value=Name(id='d', ctx=Load()),
- slice=Index(value=BinOp(left=Name(id='i', ctx=Load()), op=Add(),
- right=Name(id='i', ctx=Load()))), ctx=Store())],
- value=BinOp(left=BinOp(left=Call(func=Name(id='ord', ctx=Load()),
- args=[Name(id='i', ctx=Load())], keywords=[], starargs=None,
- kwargs=None), op=Sub(), right=Call(func=Name(id='ord',
- ctx=Load()), args=[Str(s='a')], keywords=[], starargs=None,
- kwargs=None)), op=Add(), right=Num(n=1)))], orelse=[]),
- Print(dest=None, values=[Name(id='d', ctx=Load())], nl=True)])
+ Module(body=[
+ Assign(targets=[
+ Name(id='d', ctx=Store())
+ ], value=Dict(keys=[], values=[]))
+ For(target=Name(id='i', ctx=Store()),
+ iter=Str(s='abcdefghijklm'), body=[
+ Assign(targets=[
+ Subscript(value=
+ Name(id='d', ctx=Load()),
+ slice=
+ Index(value=
+ BinOp(left=Name(id='i', ctx=Load()), op=Add(),
+ right=Name(id='i', ctx=Load()))), ctx=Store())
+ ], value=
+ BinOp(left=
+ BinOp(left=
+ Call(func=
+ Name(id='ord', ctx=Load()), args=[
+ Name(id='i', ctx=Load())
+ ], keywords=[], starargs=None, kwargs=None),
+ op=Sub(), right=Call(func=
+ Name(id='ord', ctx=Load()), args=[
+ Str(s='a')
+ ], keywords=[], starargs=None, kwargs=None)),
+ op=Add(), right=Num(n=1)))
+ ], orelse=[])
+ Print(dest=None, values=[
+ Name(id='d', ctx=Load())
+ ], nl=True)
+ ])
The :func:`literal_eval` method takes a string or an AST
-representing a literal expression, one that contains a Python
-expression containing only strings, numbers, dictionaries, etc. but no
-statements or function calls, and returns the resulting value. If you
-need to unserialize an expression but need to worry about security
-and can't risk using an :func:`eval` call, :func:`literal_eval` will
-handle it safely::
+representing a literal expression, parses and evaluates it, and
+returns the resulting value. A literal expression is a Python
+expression containing only strings, numbers, dictionaries,
+etc. but no statements or function calls. If you need to
+evaluate an expression but accept the security risk of using an
+:func:`eval` call, :func:`literal_eval` will handle it safely::
>>> literal = '("a", "b", {2:4, 3:8, 1:2})'
>>> print ast.literal_eval(literal)
@@ -2680,7 +2704,7 @@
The :mod:`future_builtins` module
--------------------------------------
-Python 3.0 makes various changes to the repertoire of built-in
+Python 3.0 makes many changes to the repertoire of built-in
functions, and most of the changes can't be introduced in the Python
2.x series because they would break compatibility.
The :mod:`future_builtins` module provides versions
@@ -2695,17 +2719,18 @@
* ``filter(*predicate*, *iterable*)``,
``map(*func*, *iterable1*, ...)``: the 3.0 versions
- return iterators, differing from the 2.x built-ins that return lists.
+ return iterators, unlike the 2.x built-ins which return lists.
* ``hex(*value*)``, ``oct(*value*)``: instead of calling the
:meth:`__hex__` or :meth:`__oct__` methods, these versions will
call the :meth:`__index__` method and convert the result to hexadecimal
- or octal.
+ or octal. :func:`oct` will use the new ``0o`` notation for its
+ result.
.. ======================================================================
-The :mod:`json` module
-----------------------
+The :mod:`json` module: JavaScript Object Notation
+--------------------------------------------------------------------
The new :mod:`json` module supports the encoding and decoding of Python types in
JSON (Javascript Object Notation). JSON is a lightweight interchange format
@@ -2723,21 +2748,22 @@
>>> json.loads(in_json) # Decode into a Python object
{"spam" : "foo", "parrot" : 42}
-It is also possible to write your own decoders and encoders to support more
-types. Pretty-printing of the JSON strings is also supported.
+It's also possible to write your own decoders and encoders to support
+more types. Pretty-printing of the JSON strings is also supported.
-:mod:`json` (originally called simplejson) was written by Bob Ippolito.
+:mod:`json` (originally called simplejson) was written by Bob
+Ippolito.
.. ======================================================================
-plistlib: A Property-List Parser
+The :mod:`plistlib` module: A Property-List Parser
--------------------------------------------------
-A commonly-used format on MacOS X is the ``.plist`` format,
-which stores basic data types (numbers, strings, lists,
-and dictionaries) and serializes them into an XML-based format.
-(It's a lot like the XML-RPC serialization of data types.)
+The ``.plist`` format is commonly used on MacOS X to
+store basic data types (numbers, strings, lists,
+and dictionaries) by serializing them into an XML-based format.
+It resembles the XML-RPC serialization of data types.
Despite being primarily used on MacOS X, the format
has nothing Mac-specific about it and the Python implementation works
@@ -2753,7 +2779,7 @@
# Create data structure
data_struct = dict(lastAccessed=datetime.datetime.now(),
version=1,
- categories=('Personal', 'Shared', 'Private'))
+ categories=('Personal','Shared','Private'))
# Create string containing XML.
plist_str = plistlib.writePlistToString(data_struct)
@@ -2798,13 +2824,13 @@
Win32 LastError variables at the outset of each wrapped call.
(Implemented by Thomas Heller; :issue:`1798`.)
-For the Unix ``errno`` variable: when creating a wrapped function,
-you can supply ``use_errno=True`` as a keyword parameter
-to the :func:`DLL` function
-and then call the module-level methods :meth:`set_errno`
-and :meth:`get_errno` to set and retrieve the error value.
+You can now retrieve the Unix ``errno`` variable after a function
+call. When creating a wrapped function, you can supply
+``use_errno=True`` as a keyword parameter to the :func:`DLL` function
+and then call the module-level methods :meth:`set_errno` and
+:meth:`get_errno` to set and retrieve the error value.
-The Win32 LastError variable is supported similarly by
+The Win32 LastError variable is similarly supported by
the :func:`DLL`, :func:`OleDLL`, and :func:`WinDLL` functions.
You supply ``use_last_error=True`` as a keyword parameter
and then call the module-level methods :meth:`set_last_error`
@@ -2820,15 +2846,15 @@
--------------------------------------------------
Bill Janssen made extensive improvements to Python 2.6's support for
-the Secure Sockets Layer by adding a new module, :mod:`ssl`, on top of
-the `OpenSSL <http://www.openssl.org/>`__ library. This new module
-provides more control over the protocol negotiated, the X.509
-certificates used, and has better support for writing SSL servers (as
-opposed to clients) in Python. The existing SSL support in the
-:mod:`socket` module hasn't been removed and continues to work,
+the Secure Sockets Layer by adding a new module, :mod:`ssl`, that's
+built atop the `OpenSSL <http://www.openssl.org/>`__ library.
+This new module provides more control over the protocol negotiated,
+the X.509 certificates used, and has better support for writing SSL
+servers (as opposed to clients) in Python. The existing SSL support
+in the :mod:`socket` module hasn't been removed and continues to work,
though it will be removed in Python 3.0.
-To use the new module, first you must create a TCP connection in the
+To use the new module, you must first create a TCP connection in the
usual way and then pass it to the :func:`ssl.wrap_socket` function.
It's possible to specify whether a certificate is required, and to
obtain certificate info by calling the :meth:`getpeercert` method.
@@ -2845,9 +2871,15 @@
Changes to Python's build process and to the C API include:
-* Python 2.6 can be built with Microsoft Visual Studio 2008.
- See the :file:`PCbuild9` directory for the build files.
- (Implemented by Christian Heimes.)
+* Python now must be compiled with C89 compilers (after 19
+ years!). This means that the Python source tree has dropped its
+ own implementations of :cfunc:`memmove` and :cfunc:`strerror`, which
+ are in the C89 standard library.
+
+* Python 2.6 can be built with Microsoft Visual Studio 2008 (version
+ 9.0), and this is the new default compiler. See the
+ :file:`PCbuild` directory for the build files. (Implemented by
+ Christian Heimes.)
* On MacOS X, Python 2.6 can be compiled as a 4-way universal build.
The :program:`configure` script
@@ -2856,11 +2888,6 @@
architectures (x86, PowerPC), 64-bit (x86-64 and PPC-64), or both.
(Contributed by Ronald Oussoren.)
-* Python now can only be compiled with C89 compilers (after 19
- years!). This means that the Python source tree can now drop its
- own implementations of :cfunc:`memmove` and :cfunc:`strerror`, which
- are in the C89 standard library.
-
* The BerkeleyDB module now has a C API object, available as
``bsddb.db.api``. This object can be used by other C extensions
that wish to use the :mod:`bsddb` module for their own purposes.
@@ -2889,14 +2916,14 @@
function, :cfunc:`PyImport_ImportModuleNoBlock`, will look for a
module in ``sys.modules`` first, then try to import it after
acquiring an import lock. If the import lock is held by another
- thread, the :exc:`ImportError` is raised.
+ thread, an :exc:`ImportError` is raised.
(Contributed by Christian Heimes.)
* Several functions return information about the platform's
floating-point support. :cfunc:`PyFloat_GetMax` returns
the maximum representable floating point value,
and :cfunc:`PyFloat_GetMin` returns the minimum
- positive value. :cfunc:`PyFloat_GetInfo` returns a dictionary
+ positive value. :cfunc:`PyFloat_GetInfo` returns an object
containing more information from the :file:`float.h` file, such as
``"mant_dig"`` (number of digits in the mantissa), ``"epsilon"``
(smallest difference between 1.0 and the next largest value
@@ -2939,7 +2966,7 @@
internal free lists of objects that can be re-used. The data
structures for these free lists now follow a naming convention: the
variable is always named ``free_list``, the counter is always named
- ``numfree``, and a macro :cmacro:`Py<typename>_MAXFREELIST` is
+ ``numfree``, and a macro ``Py<typename>_MAXFREELIST`` is
always defined.
* A new Makefile target, "make check", prepares the Python source tree
@@ -2963,6 +2990,14 @@
* The support for Windows 95, 98, ME and NT4 has been dropped.
Python 2.6 requires at least Windows 2000 SP4.
+* The new default compiler on Windows is Visual Studio 2008 (version
+ 9.0). The build directories for Visual Studio 2003 (version 7.1) and
+ 2005 (version 8.0) were moved into the PC/ directory. The new
+ :file:`PCbuild` directory supports cross compilation for X64, debug
+ builds and Profile Guided Optimization (PGO). PGO builds are roughly
+ 10% faster than normal builds. (Contributed by Christian Heimes
+ with help from Amaury Forgeot d'Arc and Martin von Loewis.)
+
* The :mod:`msvcrt` module now supports
both the normal and wide char variants of the console I/O
API. The :func:`getwch` function reads a keypress and returns a Unicode
@@ -2970,9 +3005,9 @@
takes a Unicode character and writes it to the console.
(Contributed by Christian Heimes.)
-* :func:`os.path.expandvars` will now expand environment variables
- in the form "%var%", and "~user" will be expanded into the
- user's home directory path. (Contributed by Josiah Carlson.)
+* :func:`os.path.expandvars` will now expand environment variables in
+ the form "%var%", and "~user" will be expanded into the user's home
+ directory path. (Contributed by Josiah Carlson; :issue:`957650`.)
* The :mod:`socket` module's socket objects now have an
:meth:`ioctl` method that provides a limited interface to the
@@ -2996,14 +3031,6 @@
return field values as an integer or a string.
(Contributed by Floris Bruynooghe; :issue:`2125`.)
-* The new default compiler on Windows is Visual Studio 2008 (VS 9.0). The
- build directories for Visual Studio 2003 (VS7.1) and 2005 (VS8.0)
- were moved into the PC/ directory. The new PCbuild directory supports
- cross compilation for X64, debug builds and Profile Guided Optimization
- (PGO). PGO builds are roughly 10% faster than normal builds.
- (Contributed by Christian Heimes with help from Amaury Forgeot d'Arc and
- Martin von Loewis.)
-
.. ======================================================================
Port-Specific Changes: MacOS X
@@ -3089,32 +3116,6 @@
:mod:`videoreader`, and
:mod:`WAIT`.
-
-
-.. ======================================================================
-
-
-.. _section-other:
-
-Other Changes and Fixes
-=======================
-
-As usual, there were a bunch of other improvements and bugfixes
-scattered throughout the source tree. A search through the change
-logs finds there were XXX patches applied and YYY bugs fixed between
-Python 2.5 and 2.6. Both figures are likely to be underestimates.
-
-Some of the more notable changes are:
-
-* It's now possible to prevent Python from writing any :file:`.pyc`
- or :file:`.pyo` files by either supplying the :option:`-B` switch
- or setting the :envvar:`PYTHONDONTWRITEBYTECODE` environment variable
- to any non-empty string when running the Python interpreter. These
- are also used to set the :data:`sys.dont_write_bytecode` attribute;
- Python code can change this variable to control whether bytecode
- files are subsequently written.
- (Contributed by Neal Norwitz and Georg Brandl.)
-
.. ======================================================================
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