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Diffstat (limited to 'Doc/whatsnew/2.6.rst')
| -rw-r--r-- | Doc/whatsnew/2.6.rst | 214 |
1 files changed, 192 insertions, 22 deletions
diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst index 2dc5844..4d52716 100644 --- a/Doc/whatsnew/2.6.rst +++ b/Doc/whatsnew/2.6.rst @@ -67,7 +67,6 @@ new feature. .. % Large, PEP-level features and changes should be described here. .. % Should there be a new section here for 3k migration? .. % Or perhaps a more general section describing module changes/deprecation? -.. % sets module deprecated .. % ====================================================================== Python 3.0 @@ -75,7 +74,23 @@ Python 3.0 .. % XXX add general comment about Python 3.0 features in 2.6 -.. % XXX mention -3 switch +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. + +Python 3.0 is a far-ranging redesign of Python that breaks +compatibility with the 2.x series. This means that existing Python +code will need a certain amount of conversion in order to run on +Python 3.0. However, not all the changes in 3.0 necessarily break +compatibility. In cases where new features won't cause existing code +to break, they've been backported to 2.6 and are described in this +document in the appropriate place. Some of the 3.0-derived features +are: + +* A :meth:`__complex__` method for converting objects to a complex number. +* Alternate syntax for catching exceptions: ``except TypeError as exc``. +* The addition of :func:`functools.reduce` as a synonym for the built-in + :func:`reduce` function. A new command-line switch, :option:`-3`, enables warnings about features that will be removed in Python 3.0. You can run code @@ -406,11 +421,6 @@ Other Language Changes Here are all of the changes that Python 2.6 makes to the core Python language. -* 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. - * When calling a function using the ``**`` syntax to provide keyword arguments, you are no longer required to use a Python dictionary; any mapping will now work:: @@ -426,8 +436,29 @@ Here are all of the changes that Python 2.6 makes to the core Python language. .. % Patch 1686487 +* The built-in types now have improved support for extended slicing syntax, + where various combinations of ``(start, stop, step)`` are supplied. + Previously, the support was partial and certain corner cases wouldn't work. + (Implemented by Thomas Wouters.) + + .. % Revision 57619 + +* 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 + :mod:`cmath` module will now accept objects with this method. + This is a backport of a Python 3.0 change. + (Contributed by Mark Dickinson.) + + .. % Patch #1675423 + +* 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 :func:`compile` built-in function now accepts keyword arguments - as well as positional parameters. (Contributed by XXX.) + as well as positional parameters. (Contributed by Thomas Wouters.) .. % Patch 1444529 @@ -483,21 +514,73 @@ fixes. Here's a partial list of the most notable changes, sorted alphabetically by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more complete list of changes, or look through the CVS logs for all the details. -* A new data type in the :mod:`collections` module: :class:`NamedTuple(typename, +* The :mod:`bsddb.dbshelve` module now uses the highest pickling protocol + available, instead of restricting itself to protocol 1. + (Contributed by W. Barnes.) + + .. % Patch 1551443 + +* A new data type in the :mod:`collections` module: :class:`namedtuple(typename, fieldnames)` is a factory function that creates subclasses of the standard tuple whose fields are accessible by name as well as index. For example:: - var_type = collections.NamedTuple('variable', - 'id name type size') - var = var_type(1, 'frequency', 'int', 4) + >>> var_type = collections.namedtuple('variable', + ... 'id name type size') + # Names are separated by spaces or commas. + # 'id, name, type, size' would also work. + >>> var_type.__fields__ + ('id', 'name', 'type', 'size') + + >>> var = var_type(1, 'frequency', 'int', 4) + >>> print var[0], var.id # Equivalent + 1 1 + >>> print var[2], var.type # Equivalent + int int + >>> var.__asdict__() + {'size': 4, 'type': 'int', 'id': 1, 'name': 'frequency'} + >>> v2 = var.__replace__('name', 'amplitude') + >>> v2 + variable(id=1, name='amplitude', type='int', size=4) - print var[0], var.id # Equivalent - print var[2], var.type # Equivalent + (Contributed by Raymond Hettinger.) + +* Another change to the :mod:`collections` module is that the + :class:`deque` type now supports an optional `maxlen` parameter; + if supplied, the deque's size will be restricted to no more + than ``maxlen`` items. Adding more items to a full deque causes + old items to be discarded. + + :: + + >>> from collections import deque + >>> dq=deque(maxlen=3) + >>> dq + deque([], maxlen=3) + >>> dq.append(1) ; dq.append(2) ; dq.append(3) + >>> dq + deque([1, 2, 3], maxlen=3) + >>> dq.append(4) + >>> dq + deque([2, 3, 4], maxlen=3) (Contributed by Raymond Hettinger.) +* The :mod:`ctypes` module now supports a :class:`c_bool` datatype + that represents the C99 ``bool`` type. (Contributed by David Remahl.) + + .. % Patch 1649190 + + The :mod:`ctypes` string, buffer and array types also have improved + support for extended slicing syntax, + where various combinations of ``(start, stop, step)`` are supplied. + (Implemented by Thomas Wouters.) + + .. % Revision 57769 + + * A new method in the :mod:`curses` module: for a window, :meth:`chgat` changes - the display characters for a certain number of characters on a single line. :: + the display characters for a certain number of characters on a single line. + :: # Boldface text starting at y=0,x=21 # and affecting the rest of the line. @@ -505,11 +588,33 @@ complete list of changes, or look through the CVS logs for all the details. (Contributed by Fabian Kreutz.) +* The :mod:`decimal` module was updated to version 1.66 of + `the General Decimal Specification <http://www2.hursley.ibm.com/decimal/decarith.html>`__. New features + include some methods for some basic mathematical functions such as + :meth:`exp` and :meth:`log10`:: + + >>> Decimal(1).exp() + Decimal("2.718281828459045235360287471") + >>> Decimal("2.7182818").ln() + Decimal("0.9999999895305022877376682436") + >>> Decimal(1000).log10() + Decimal("3") + + (Implemented by Facundo Batista and Mark Dickinson.) + * An optional ``timeout`` parameter was added to the :class:`ftplib.FTP` class constructor as well as the :meth:`connect` method, specifying a timeout measured in seconds. (Added by Facundo Batista.) +* The :func:`reduce` built-in function is also available in the + :mod:`functools` module. In Python 3.0, the built-in is dropped and it's + only available from :mod:`functools`; currently there are no plans + to drop the built-in in the 2.x series. (Patched by + Christian Heimes.) + + .. % Patch 1739906 + * The :func:`glob.glob` function can now return Unicode filenames if a Unicode path was used and Unicode filenames are matched within the directory. @@ -548,7 +653,7 @@ complete list of changes, or look through the CVS logs for all the details. .. % Patch #1490190 -* The :func:`os.walk` function now has a "followlinks" parameter. If +* 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 parameter's default value is false. Note that the function can fall @@ -557,6 +662,12 @@ complete list of changes, or look through the CVS logs for all the details. .. % Patch 1273829 +* The ``os.environ`` object's :meth:`clear` method will now unset the + environment variables using :func:`os.unsetenv` in addition to clearing + the object's keys. (Contributed by Martin Horcicka.) + + .. % Patch #1181 + * In the :mod:`os.path` module, the :func:`splitext` function has been changed to not split on leading period characters. This produces better results when operating on Unix's dot-files. @@ -574,10 +685,17 @@ complete list of changes, or look through the CVS logs for all the details. On Windows, :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 XXX.) + user's home directory path. (Contributed by Josiah Carlson.) .. % Patch 957650 +* The Python debugger provided by the :mod:`pdb` module + gained a new command: "run" restarts the Python program being debugged, + and can optionally take new command-line arguments for the program. + (Contributed by Rocky Bernstein.) + + .. % Patch #1393667 + * New functions in the :mod:`posix` module: :func:`chflags` and :func:`lchflags` are wrappers for the corresponding system calls (where they're available). Constants for the flag values are defined in the :mod:`stat` module; some @@ -587,6 +705,9 @@ complete list of changes, or look through the CVS logs for all the details. * The :mod:`rgbimg` module has been removed. +* The :mod:`sets` module has been deprecated; it's better to + use the built-in :class:`set` and :class:`frozenset` types. + * The :mod:`smtplib` module now supports SMTP over SSL thanks to the addition of the :class:`SMTP_SSL` class. This class supports an interface identical to the existing :class:`SMTP` class. Both @@ -701,8 +822,47 @@ complete list of changes, or look through the CVS logs for all the details. (Added by Facundo Batista.) +* The XML-RPC classes :class:`SimpleXMLRPCServer` and :class:`DocXMLRPCServer` + classes can now be prevented from immediately opening and binding to + their socket by passing True as the ``bind_and_activate`` + constructor parameter. This can be used to modify the instance's + :attr:`allow_reuse_address` attribute before calling the + :meth:`server_bind` and :meth:`server_activate` methods to + open the socket and begin listening for connections. + (Contributed by Peter Parente.) + + .. % Patch 1599845 + + :class:`SimpleXMLRPCServer` also has a :attr:`_send_traceback_header` + attribute; if true, the exception and formatted traceback are returned + as HTTP headers "X-Exception" and "X-Traceback". This feature is + for debugging purposes only and should not be used on production servers + because the tracebacks could possibly reveal passwords or other sensitive + information. (Contributed by Alan McIntyre as part of his + project for Google's Summer of Code 2007.) + .. % ====================================================================== -.. % whole new modules get described in \subsections here +.. % whole new modules get described in subsections here + +Improved SSL Support +-------------------------------------------------- + +Bill Janssen made extensive improvements to Python 2.6's support for +SSL. + +XXX use ssl.sslsocket - subclass of socket.socket. + +XXX Can specify if certificate is required, and obtain certificate info +by calling getpeercert method. + +XXX sslwrap() behaves like socket.ssl + +XXX Certain features require the OpenSSL package to be installed, notably + the 'openssl' binary. + +.. seealso:: + + SSL module documentation. .. % ====================================================================== @@ -712,7 +872,13 @@ Build and C API Changes Changes to Python's build process and to the C API include: -* Detailed changes are listed here. +* 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. + (Contributed by Duncan Grisby.) + + .. % Patch 1551895 + .. % ====================================================================== @@ -737,7 +903,7 @@ are likely to be underestimates. Some of the more notable changes are: -* Details go here. +* Details will go here. .. % ====================================================================== @@ -748,8 +914,12 @@ Porting to Python 2.6 This section lists previously described changes that may require changes to your code: -* The :mod:`socket` module exception :exc:`socket.error` now inherits from - :exc:`IOError`. +* The :mod:`socket` module exception :exc:`socket.error` now inherits + from :exc:`IOError`. Previously it wasn't a subclass of + :exc:`StandardError` but now it is, through :exc:`IOError`. + (Implemented by Gregory P. Smith.) + + .. % http://bugs.python.org/issue1706815 .. % ====================================================================== |