[Python-checkins] r59562 - python/trunk/Doc/whatsnew/2.6.rst
andrew.kuchling
python-checkins at python.org
Wed Dec 19 03:02:05 CET 2007
Author: andrew.kuchling
Date: Wed Dec 19 03:02:04 2007
New Revision: 59562
Modified:
python/trunk/Doc/whatsnew/2.6.rst
Log:
Add a bunch of items
Modified: python/trunk/Doc/whatsnew/2.6.rst
==============================================================================
--- python/trunk/Doc/whatsnew/2.6.rst (original)
+++ python/trunk/Doc/whatsnew/2.6.rst Wed Dec 19 03:02:04 2007
@@ -72,8 +72,6 @@
Python 3.0
================
-.. % XXX add general comment about Python 3.0 features in 2.6
-
The development cycle for Python 2.6 also saw the release of the first
alphas of Python 3.0, and the development of 3.0 has influenced
a number of features in 2.6.
@@ -95,7 +93,9 @@
A new command-line switch, :option:`-3`, enables warnings
about features that will be removed in Python 3.0. You can run code
with this switch to see how much work will be necessary to port
-code to 3.0.
+code to 3.0. The value of this switch is available
+to Python code as the boolean variable ``sys.py3kwarning``,
+and to C extension code as :cdata:`Py_Py3kWarningFlag`.
.. seealso::
@@ -103,6 +103,62 @@
Python 3.0 and various features that have been accepted, rejected,
or are still under consideration.
+
+Development Changes
+==================================================
+
+While 2.6 was being developed, the Python development process
+underwent two significant changes: the developer group
+switched from SourceForge's issue tracker to a customized
+Roundup installation, and the documentation was converted from
+LaTeX to reStructured Text.
+
+
+New Issue Tracker: Roundup
+--------------------------------------------------
+
+XXX write this.
+
+
+New Documentation Format: ReStructured Text
+--------------------------------------------------
+
+Python's documentation had been written using LaTeX since the
+project's inception around 1989. At that time, most documentation was
+printed out for later study, not viewed online. LaTeX was widely used
+because it provided attractive printed output while
+remaining straightforward to write, once the basic rules
+of the markup have been learned.
+
+LaTeX is still used today for writing technical publications destined
+for printing, but the landscape for programming tools has shifted. We
+no longer print out reams of documentation; instead, we browse through
+it online and HTML is the most important format to support.
+Unfortunately, converting LaTeX to HTML is fairly complicated, and
+Fred L. Drake Jr., the Python documentation editor for many years,
+spent a lot of time wrestling the conversion process into shape.
+Occasionally people would suggest converting the documentation into
+SGML or, later, XML, but performing a good conversion is a major task
+and no one pursued the task to completion.
+
+During the 2.6 development cycle, Georg Brandl put a substantial
+effort into building a new toolchain called Sphinx
+for processing the documentation.
+The input format is reStructured Text,
+a markup commonly used in the Python community that supports
+custom extensions and directives. Sphinx concentrates
+on its HTML output, producing attractively styled
+and modern HTML. (XXX finish this -- mention new search feature)
+
+.. seealso::
+
+ `Docutils <http://docutils.sf.net>`__: The fundamental
+ reStructured Text parser and toolset.
+
+ `Documenting Python <XXX>`__: Describes how to write for
+ Python's documentation.
+
+
PEP 343: The 'with' statement
=============================
@@ -352,6 +408,24 @@
.. % ======================================================================
+.. _pep-0366:
+
+PEP 366: Explicit Relative Imports From a Main Module
+============================================================
+
+Python's :option:`-m` switch allows running a module as a script.
+When you ran a module that was located inside a package, relative
+imports didn't work correctly.
+
+The fix in Python 2.6 adds a :attr:`__package__` attribute to modules.
+When present, relative imports will be relative to the value of this
+attribute instead of the :attr:`__name__` attribute. PEP 302-style
+importers can then set :attr:`__package__`. The :mod:`runpy` module
+that implements the :option:`-m` switch now does this, so relative imports
+can now be used in scripts running from inside a package.
+
+.. % ======================================================================
+
.. _pep-3110:
PEP 3110: Exception-Handling Changes
@@ -414,7 +488,7 @@
:pep:`3119` - Introducing Abstract Base Classes
PEP written by Guido van Rossum and Talin.
Implemented by XXX.
- Backported to 2.6 by Benjamin Aranguren (with Alex Martelli).
+ Backported to 2.6 by Benjamin Aranguren, with Alex Martelli.
Other Language Changes
======================
@@ -443,6 +517,25 @@
.. % Revision 57619
+* Properties now have two attributes,
+ :attr:`setter` and :attr:`deleter`, that are useful shortcuts for
+ adding a setter or deleter function to an existing property.
+ You would use them like this::
+
+ class C(object):
+ @property
+ def x(self):
+ return self._x
+
+ @x.setter
+ def x(self, value):
+ self._x = value
+
+ @x.deleter
+ def x(self):
+ del self._x
+
+
* C functions and methods that use
:cfunc:`PyComplex_AsCComplex` will now accept arguments that
have a :meth:`__complex__` method. In particular, the functions in the
@@ -452,11 +545,26 @@
.. % Patch #1675423
+ A numerical nicety: when creating a complex number from two floats
+ on systems that support signed zeros (-0 and +0), the
+ :func:`complex()` constructor will now preserve the sign
+ of the zero.
+
+ .. % Patch 1507
+
* Changes to the :class:`Exception` interface
as dictated by :pep:`352` continue to be made. For 2.6,
the :attr:`message` attribute is being deprecated in favor of the
:attr:`args` attribute.
+* The :exc:`GeneratorExit` exception now subclasses
+ :exc:`BaseException` instead of :exc:`Exception`. This means
+ that an exception handler that does ``except Exception:``
+ will not inadvertently catch :exc:`GeneratorExit`.
+ (Contributed by Chad Austin.)
+
+ .. % Patch #1537
+
* The :func:`compile` built-in function now accepts keyword arguments
as well as positional parameters. (Contributed by Thomas Wouters.)
@@ -653,6 +761,20 @@
.. % Patch #1490190
+* The :mod:`new` module has been removed from Python 3.0.
+ Importing it therefore
+ triggers a warning message when Python is running in 3.0-warning
+ mode.
+
+* New functions in the :mod:`os` module include
+ ``fchmod(fd, mode)``, ``fchown(fd, uid, gid)``,
+ and ``lchmod(path, mode)``, on operating systems that support these
+ functions. :func:`fchmod` and :func:`fchown` let you change the mode
+ and ownership of an opened file, and :func:`lchmod` changes the mode
+ of a symlink.
+
+ (Contributed by Georg Brandl and Christian Heimes.)
+
* The :func:`os.walk` function now has a ``followlinks`` parameter. If
set to True, it will follow symlinks pointing to directories and
visit the directory's contents. For backward compatibility, the
@@ -703,6 +825,15 @@
changed and :const:`UF_APPEND` to indicate that data can only be appended to the
file. (Contributed by M. Levinson.)
+* The :mod:`random` module's :class:`Random` objects can
+ now be pickled on a 32-bit system and unpickled on a 64-bit
+ system, and vice versa. Unfortunately, this change also means
+ that Python 2.6's :class:`Random` objects can't be unpickled correctly
+ on earlier versions of Python.
+ (Contributed by Shawn Ligocki.)
+
+ .. % Issue 1727780
+
* The :mod:`rgbimg` module has been removed.
* The :mod:`sets` module has been deprecated; it's better to
@@ -725,6 +856,17 @@
.. % Patch #957003
+* A new variable in the :mod:`sys` module,
+ :attr:`float_info`, is a dictionary
+ containing information about the platform's floating-point support
+ derived from the :file:`float.h` file. Key/value pairs
+ in this dictionary include
+ ``"mant_dig"`` (number of digits in the mantissa), ``"epsilon"``
+ (smallest difference between 1.0 and the next largest value
+ representable), and several others. (Contributed by Christian Heimes.)
+
+ .. % Patch 1534
+
* The :mod:`tarfile` module now supports POSIX.1-2001 (pax) and
POSIX.1-1988 (ustar) format tarfiles, in addition to the GNU tar
format that was already supported. The default format
@@ -883,6 +1025,17 @@
.. % Patch 1551895
+* 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
+ 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
+ representable), and several others.
+
+ .. % Issue 1534
.. % ======================================================================
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