% $Id$
\title{What's New in Python 2.3}
-\release{0.09}
+\release{0.10}
\author{A.M.\ Kuchling}
\authoraddress{\email{amk@amk.ca}}
\maketitle
\tableofcontents
+% To do:
% MacOS framework-related changes (section of its own, probably)
%\section{Introduction \label{intro}}
{\large This article is a draft, and is currently up to date for
-Python 2.3alpha1. Please send any additions, comments or errata to
+Python 2.3alpha2. Please send any additions, comments or errata to
the author.}
This article explains the new features in Python 2.3. The tentative
Log records are usually propagated up the hierarchy, so a message
logged to \samp{server.auth} is also seen by \samp{server} and
-\samp{root}, but a handler can prevent this by setting its
+\samp{root}, but a \class{Logger} can prevent this by setting its
\member{propagate} attribute to \constant{False}.
There are more classes provided by the \module{logging} package that
number of different \class{Handler} instances. Loggers and handlers
can also have an attached list of filters, and each filter can cause
the \class{LogRecord} to be ignored or can modify the record before
-passing it along. \class{LogRecord} instances are converted to text
-for output by a \class{Formatter} class. All of these classes can be
-replaced by your own specially-written classes.
+passing it along. When they're finally output, \class{LogRecord}
+instances are converted to text by a \class{Formatter} class. All of
+these classes can be replaced by your own specially-written classes.
With all of these features the \module{logging} package should provide
enough flexibility for even the most complicated applications. This
-is only a partial overview of the \module{logging} package, so please
-see the \ulink{package's reference
-documentation}{../lib/module-logging.html} for all of the details.
-Reading \pep{282} will also be helpful.
+is only an incomplete overview of its features, so please see the
+\ulink{package's reference documentation}{../lib/module-logging.html}
+for all of the details. Reading \pep{282} will also be helpful.
\begin{seealso}
\item Built-in types now support the extended slicing syntax,
as described in section~\ref{section-slices} of this document.
-\item Dictionaries have a new method, \method{pop(\var{key})}, that
-returns the value corresponding to \var{key} and removes that
-key/value pair from the dictionary. \method{pop()} will raise a
-\exception{KeyError} if the requested key isn't present in the
-dictionary:
+\item Dictionaries have a new method, \method{pop(\var{key}\optional{,
+\var{default}})}, that returns the value corresponding to \var{key}
+and removes that key/value pair from the dictionary. If the requested
+key isn't present in the dictionary, \var{default} is returned if
+it's specified and \exception{KeyError} raised if it isn't.
\begin{verbatim}
>>> d = {1:2}
implements the text wrapping strategy. Both the
\class{TextWrapper} class and the \function{wrap()} and
\function{fill()} functions support a number of additional keyword
-arguments for fine-tuning the formatting; consult the module's
-documentation for details.
-%XXX add a link to the module docs?
+arguments for fine-tuning the formatting; consult the \ulink{module's
+documentation}{../lib/module-textwrap.html} for details.
(Contributed by Greg Ward.)
\item The \module{thread} and \module{threading} modules now have
intention is to simplify thread-aware modules (ones that \emph{don't}
rely on threads to run) by putting the following code at the top:
-% XXX why as _threading?
\begin{verbatim}
try:
import threading as _threading
statement and making the code slightly clearer. This module will not
magically make multithreaded code run without threads; code that waits
for another thread to return or to do something will simply hang
-forever.
+forever. (In this example, \module{_threading} is used as the module
+name to make it clear that the module being used is not necessarily
+the actual \module{threading} module.)
\item The \module{time} module's \function{strptime()} function has
long been an annoyance because it uses the platform C library's
implementation that's written in pure Python and should behave
identically on all platforms.
+\item The new \module{timeit} module helps measure how long snippets
+of Python code take to execute. The \file{timeit.py} file can be run
+directly from the command line, or the module's \class{Timer} class
+can be imported and used directly. Here's a short example that
+figures out whether it's faster to convert an 8-bit string to Unicode
+by appending an empty Unicode string to it or by using the
+\function{unicode()} function:
+
+\begin{verbatim}
+import timeit
+
+timer1 = timeit.Timer('unicode("abc")')
+timer2 = timeit.Timer('"abc" + u""')
+
+# Run three trials
+print timer1.repeat(repeat=3, number=100000)
+print timer2.repeat(repeat=3, number=100000)
+
+# On my laptop this outputs:
+# [0.36831796169281006, 0.37441694736480713, 0.35304892063140869]
+# [0.17574405670166016, 0.18193507194519043, 0.17565798759460449]
+\end{verbatim}
+
+
\item The \module{UserDict} module has a new \class{DictMixin} class which
defines all dictionary methods for classes that already have a minimum
mapping interface. This greatly simplifies writing classes that need
\class{date} or \class{datetime}.
For more information, refer to the \ulink{module's reference
-documentation}{..//lib/module-datetime.html}.
+documentation}{../lib/module-datetime.html}.
(Contributed by Tim Peters.)
\end{verbatim}
% $ prevent Emacs tex-mode from getting confused
+See the \ulink{module's documentation}{../lib/module-optparse.html}
+for more details.
+
Optik was written by Greg Ward, with suggestions from the readers of
the Getopt SIG.
-\begin{seealso}
-\seeurl{http://optik.sourceforge.net/}
-{The Optik site has tutorial and reference documentation for
-\module{optparse}.
-% XXX change to point to Python docs, when those docs get written.
-}
-\end{seealso}
-
%======================================================================
\section{Specialized Object Allocator (pymalloc)\label{section-pymalloc}}
The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
-article: Jeff Bauer, Simon Brunning, Michael Chermside, Andrew Dalke, Scott David
-Daniels, Fred~L. Drake, Jr., Kelly Gerber, Raymond Hettinger, Michael
-Hudson, Chris Lambert, Detlef Lannert, Martin von L\"owis, Andrew MacIntyre, Lalo
-Martins, Gustavo Niemeyer, Neal Norwitz, Hans Nowak, Chris Reedy,
-Vinay Sajip, Neil Schemenauer, Roman Suzi, Jason Tishler, Just van~Rossum.
+article: Jeff Bauer, Simon Brunning, Brett Cannon, Michael Chermside,
+Andrew Dalke, Scott David Daniels, Fred~L. Drake, Jr., Kelly Gerber,
+Raymond Hettinger, Michael Hudson, Chris Lambert, Detlef Lannert,
+Martin von L\"owis, Andrew MacIntyre, Lalo Martins, Gustavo Niemeyer,
+Neal Norwitz, Hans Nowak, Chris Reedy, Vinay Sajip, Neil Schemenauer,
+Roman Suzi, Jason Tishler, Just van~Rossum.
\end{document}
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