[Python-checkins] r84548 - python/branches/py3k/Doc/whatsnew/3.2.rst
raymond.hettinger
python-checkins at python.org
Mon Sep 6 03:16:46 CEST 2010
Author: raymond.hettinger
Date: Mon Sep 6 03:16:46 2010
New Revision: 84548
Log:
More updates to whatsnew3.2
Modified:
python/branches/py3k/Doc/whatsnew/3.2.rst
Modified: python/branches/py3k/Doc/whatsnew/3.2.rst
==============================================================================
--- python/branches/py3k/Doc/whatsnew/3.2.rst (original)
+++ python/branches/py3k/Doc/whatsnew/3.2.rst Mon Sep 6 03:16:46 2010
@@ -53,22 +53,18 @@
PEP 391: Dictionary Based Configuration for Logging
====================================================
-The :mod:`logging` module had two ways of configuring the module, either by calling
-functions for each option or by reading an external file saved in a :mod:`ConfigParser`
-format. Those options did not provide the flexibility to create configurations
-from JSON or YAML files and they did not support incremental configuration, which
-is needed for specifying logger options from a command line.
+The :mod:`logging` module provided two kinds of configuration, one style with
+function calls for each option or another style driven by an external file saved
+in a :mod:`ConfigParser` format. Those options did not provide the flexibility
+to create configurations from JSON or YAML files, nor they did not support
+incremental configuration, which is needed for specifying logger options from a
+command line.
To support a more flexible style, the module now offers
-:func:`logging.config.dictConfig` to use dictionaries to specify logger
-configuration (including formatters, handlers, filters, and loggers). For
-example:
-
->>> import logging.config
->>> logging.config.dictConfig(json.load(open('log.cfg', 'rb')))
-
-The above fragment configures logging from a JSON-encoded dictionary stored in a
-file called "log.cfg". Here's a working example of a configuration dictionary::
+:func:`logging.config.dictConfig` for specifying logging configuration with
+plain Python dictionaries. The configuration options include formatters,
+handlers, filters, and loggers. Here's a working example of a configuration
+dictionary::
{"version": 1,
"formatters": {"brief": {"format": "%(levelname)-8s: %(name)-15s: %(message)s"},
@@ -87,6 +83,15 @@
},
"root": {"level": "DEBUG", "handlers": ["console", "console_priority"]}}
+
+If that dictionary is stored in a file called "conf.json", it can loaded
+and called with code like this::
+
+ >>> import logging.config
+ >>> logging.config.dictConfig(json.load(open('conf.json', 'rb')))
+ >>> logging.info("Transaction completed normally")
+ >>> logging.critical("Abnormal termination")
+
.. seealso::
:pep:`391` - Dictionary Based Configuration for Logging
@@ -119,16 +124,16 @@
* Imported modules now have a :attr:`__cached__` attribute which stores the name
of the actual file that was imported:
- >>> import collections
- >>> collections.__cached__
- 'c:/py32/lib/__pycache__/collections.cpython-32.pyc'
+ >>> import collections
+ >>> collections.__cached__
+ 'c:/py32/lib/__pycache__/collections.cpython-32.pyc'
* The tag that is unique to each interpreter is accessible from the :mod:`imp`
module:
- >>> import imp
- >>> imp.get_tag()
- 'cpython-32'
+ >>> import imp
+ >>> imp.get_tag()
+ 'cpython-32'
* Scripts that try to deduce source filename from the imported file now need to
be smarter. It is no longer sufficient to simply strip the "c" from a ".pyc"
@@ -199,10 +204,10 @@
caused confusion and is no longer needed now that the shortest possible
:func:`repr` is displayed by default:
- >>> repr(math.pi)
- '3.141592653589793'
- >>> str(math.pi)
- '3.141592653589793'
+ >>> repr(math.pi)
+ '3.141592653589793'
+ >>> str(math.pi)
+ '3.141592653589793'
(Proposed and implemented by Mark Dickinson; :issue:`9337`.)
@@ -218,8 +223,22 @@
* The :mod:`abc` module now supports :func:`~abc.abstractclassmethod` and
:func:`~abc.abstractstaticmethod`.
- (:issue:`5867`.)
+ (Patch submitted by Daniel Urban; :issue:`5867`.)
+
+* A warning message will now get printed at interpreter shutdown if the
+ :data:`gc.garbage` list isn't empty. This is meant to make the programmer
+ aware that their code contains object finalization issues.
+
+ (Added by Antoine Pitrou; :issue:`477863`.)
+
+* Mark Dickinson crafted an elegant and efficient scheme for assuring that
+ different numeric datatypes will have the same hash value whenever their
+ actual values are equal::
+
+ >>> assert hash(Fraction(3, 2)) == hash(1.5) == \
+ hash(Decimal("1.5")) == hash(complex(1.5, 0))
+ (See :issue:`8188`.)
New, Improved, and Deprecated Modules
=====================================
@@ -263,26 +282,28 @@
* The :class:`ftplib.FTP` class now supports the context manager protocol to
unconditionally consume :exc:`socket.error` exceptions and to close the FTP
- connection when done:
+ connection when done::
- >>> from ftplib import FTP
- >>> with FTP("ftp1.at.proftpd.org") as ftp:
- ... ftp.login()
- ... ftp.dir()
- ...
- '230 Anonymous login ok, restrictions apply.'
- dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 .
- dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 ..
- dr-xr-xr-x 5 ftp ftp 4096 May 6 10:43 CentOS
- dr-xr-xr-x 3 ftp ftp 18 Jul 10 2008 Fedora
+ >>> from ftplib import FTP
+ >>> with FTP("ftp1.at.proftpd.org") as ftp:
+ ... ftp.login()
+ ... ftp.dir()
+ ...
+ '230 Anonymous login ok, restrictions apply.'
+ dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 .
+ dr-xr-xr-x 9 ftp ftp 154 May 6 10:43 ..
+ dr-xr-xr-x 5 ftp ftp 4096 May 6 10:43 CentOS
+ dr-xr-xr-x 3 ftp ftp 18 Jul 10 2008 Fedora
+
+ Other file-like objects such as :class:`mmap.mmap` and :func:`fileinput.input`
+ also grew auto-closing context managers::
+
+ with fileinput.input(files=('log1.txt', 'log2.txt')) as f:
+ for line in f:
+ process(line)
- (Contributed by Tarek Ziadé and Giampaolo Rodolà; :issue:`4972`.)
-
-* A warning message will now get printed at interpreter shutdown if the
- :data:`gc.garbage` list isn't empty. This is meant to make the programmer
- aware that their code contains object finalization issues.
-
- (Added by Antoine Pitrou; :issue:`477863`.)
+ (Contributed by Tarek Ziadé and Giampaolo Rodolà in :issue:`4972`, and
+ by Georg Brandl in :issue:`8046` and :issue:`1286`.)
* The :mod:`os` module now has the :const:`ST_RDONLY` and :const:`ST_NOSUID`
constants, for use with the :func:`~os.statvfs` function.
@@ -395,15 +416,39 @@
argument. (Contributed by Torsten Landschoff; :issue:`850728`.)
-.. Optimizations
- =============
+Optimizations
+=============
- Major performance enhancements have been added:
+A number of small performance enhancements have been added:
- * Stub
+* JSON decoding performance is improved and memory consumption is reduced
+ whenever the same string is repeated for multiple keys.
+
+ (Contributed by Antoine Pitrou; :issue:`7451`.)
+
+- Python's peephole optimizer now recognizes patterns such ``x in {1, 2, 3}`` as
+ being a test for membership in a set of constants. The optimizer recasts the
+ :class:`set` as a :class:`frozenset` and stores the pre-built constant.
+
+ Now that the speed penalty is gone, it is practical to start writing
+ membership tests using set-notation. This style is both semantically clear
+ and operationally fast::
+
+ extension = name.rpartition('.')[2]
+ if extension in {'xml', 'html', 'xhtml', 'css'}:
+ handle(name)
+
+ (Patch and additional tests by Dave Malcolm; :issue:`6690`).
+
+* The fast-search algorithm in stringlib is now used by the :meth:`split`,
+ :meth:`rsplit`, :meth:`splitlines` and :meth:`replace` methods on
+ :class:`bytes`, :class:`bytearray` and :class:`str` objects. Likewise, the
+ algorithm is also used by :meth:`rfind`, :meth:`rindex`, :meth:`rsplit` and
+ :meth:`rpartition`.
+ (Patch by Florent Xicluna in :issue:`7622` and :issue:`7462`.)
-Filenames and unicode
+Filenames and Unicode
=====================
The filesystem encoding can be specified by setting the
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