| \documentclass{howto} |
| \usepackage{distutils} |
| % $Id$ |
| |
| % Rules for maintenance: |
| % |
| % * Anyone can add text to this document. Do not spend very much time |
| % on the wording of your changes, because your text will probably |
| % get rewritten to some degree. |
| % |
| % * The maintainer will go through Misc/NEWS periodically and add |
| % changes; it's therefore more important to add your changes to |
| % Misc/NEWS than to this file. |
| % |
| % * This is not a complete list of every single change; completeness |
| % is the purpose of Misc/NEWS. Some changes I consider too small |
| % or esoteric to include. If such a change is added to the text, |
| % I'll just remove it. (This is another reason you shouldn't spend |
| % too much time on writing your addition.) |
| % |
| % * If you want to draw your new text to the attention of the |
| % maintainer, add 'XXX' to the beginning of the paragraph or |
| % section. |
| % |
| % * It's OK to just add a fragmentary note about a change. For |
| % example: "XXX Describe the transmogrify() function added to the |
| % socket module." The maintainer will research the change and |
| % write the necessary text. |
| % |
| % * You can comment out your additions if you like, but it's not |
| % necessary (especially when a final release is some months away). |
| % |
| % * Credit the author of a patch or bugfix. Just the name is |
| % sufficient; the e-mail address isn't necessary. |
| % |
| % * It's helpful to add the bug/patch number as a comment: |
| % |
| % % Patch 12345 |
| % XXX Describe the transmogrify() function added to the socket |
| % module. |
| % (Contributed by P.Y. Developer.) |
| % |
| % This saves the maintainer the effort of going through the SVN log |
| % when researching a change. |
| |
| \title{What's New in Python 2.6} |
| \release{0.0} |
| \author{A.M. Kuchling} |
| \authoraddress{\email{amk@amk.ca}} |
| |
| \begin{document} |
| \maketitle |
| \tableofcontents |
| |
| This article explains the new features in Python 2.6. No release date |
| for Python 2.6 has been set; it will probably be released in late 2007. |
| |
| % Compare with previous release in 2 - 3 sentences here. |
| |
| 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. |
| % add hyperlink when the documentation becomes available online. |
| If you want to understand the complete implementation and design |
| rationale, refer to the PEP for a particular 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 |
| |
| %====================================================================== |
| \section{Other Language Changes} |
| |
| Here are all of the changes that Python 2.6 makes to the core Python |
| language. |
| |
| \begin{itemize} |
| |
| % Bug 1569356 |
| \item An obscure change: when you use the the \function{locals()} |
| function inside a \keyword{class} statement, the resulting dictionary |
| no longer returns free variables. (Free variables, in this case, are |
| variables referred to in the \keyword{class} statement |
| that aren't attributes of the class.) |
| |
| \end{itemize} |
| |
| |
| %====================================================================== |
| \subsection{Optimizations} |
| |
| \begin{itemize} |
| |
| % Patch 1624059 |
| \item Internally, a bit is now set in type objects to indicate some of |
| the standard built-in types. This speeds up checking if an object is |
| a subclass of one of these types. (Contributed by Neal Norwitz.) |
| |
| \end{itemize} |
| |
| The net result of the 2.6 optimizations is that Python 2.6 runs the |
| pystone benchmark around XX\% faster than Python 2.5. |
| |
| |
| %====================================================================== |
| \section{New, Improved, and Deprecated Modules} |
| |
| As usual, Python's standard library received a number of enhancements and |
| bug 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. |
| |
| \begin{itemize} |
| |
| \item New data type in the \module{collections} module: |
| \class{NamedTuple(\var{typename}, \var{fieldnames})} is a factory function that |
| creates subclasses of the standard tuple whose fields are accessible |
| by name as well as index. For example: |
| |
| \begin{verbatim} |
| var_type = collections.NamedTuple('variable', |
| 'id name type size') |
| var = var_type(1, 'frequency', 'int', 4) |
| |
| print var[0], var.id # Equivalent |
| print var[2], var.type # Equivalent |
| \end{verbatim} |
| |
| (Contributed by Raymond Hettinger.) |
| |
| \item New method in the \module{curses} module: |
| for a window, \method{chgat()} changes the display characters for a |
| certain number of characters on a single line. |
| |
| \begin{verbatim} |
| # Boldface text starting at y=0,x=21 |
| # and affecting the rest of the line. |
| stdscr.chgat(0,21, curses.A_BOLD) |
| \end{verbatim} |
| |
| (Contributed by Fabian Kreutz.) |
| |
| \item The \module{gopherlib} module has been removed. |
| |
| \item New function in the \module{heapq} module: |
| \function{merge(iter1, iter2, ...)} |
| takes any number of iterables that return data |
| \emph{in sorted order}, |
| and |
| returns a new iterator that returns the contents of |
| all the iterators, also in sorted order. For example: |
| |
| \begin{verbatim} |
| heapq.merge([1, 3, 5, 9], [2, 8, 16]) -> |
| [1, 2, 3, 5, 8, 9, 16] |
| \end{verbatim} |
| |
| (Contributed by Raymond Hettinger.) |
| |
| \item New function in the \module{itertools} module: |
| \function{izip_longest(iter1, iter2, ...\optional{, fillvalue})} |
| makes tuples from each of the elements; if some of the iterables |
| are shorter than others, the missing values |
| are set to \var{fillvalue}. For example: |
| |
| \begin{verbatim} |
| itertools.izip_longest([1,2,3], [1,2,3,4,5]) -> |
| [(1, 1), (2, 2), (3, 3), (None, 4), (None, 5)] |
| \end{verbatim} |
| |
| (Contributed by Raymond Hettinger.) |
| |
| \item The \module{macfs} module has been removed. This in turn |
| required the \function{macostools.touched()} function to be removed |
| because it depended on the \module{macfs} module. |
| |
| % Patch #1490190 |
| \item New functions in the \module{posix} module: \function{chflags()} |
| and \function{lchflags()} are wrappers for the corresponding system |
| calls (where they're available). Constants for the flag values are |
| defined in the \module{stat} module; some possible values include |
| \constant{UF_IMMUTABLE} to signal the file may not be changed and |
| \constant{UF_APPEND} to indicate that data can only be appended to the |
| file. (Contributed by M. Levinson.) |
| |
| \item The \module{rgbimg} module has been removed. |
| |
| \item The \module{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. (Contributed by Monty Taylor.) |
| |
| \item The \module{test.test_support} module now contains a |
| \function{EnvironmentVarGuard} context manager that |
| supports temporarily changing environment variables and |
| automatically restores them to their old values. |
| (Contributed by Brett Cannon.) |
| |
| \end{itemize} |
| |
| |
| %====================================================================== |
| % whole new modules get described in \subsections here |
| |
| |
| % ====================================================================== |
| \section{Build and C API Changes} |
| |
| Changes to Python's build process and to the C API include: |
| |
| \begin{itemize} |
| |
| \item Detailed changes are listed here. |
| |
| \end{itemize} |
| |
| |
| %====================================================================== |
| \subsection{Port-Specific Changes} |
| |
| Platform-specific changes go here. |
| |
| |
| %====================================================================== |
| \section{Other Changes and Fixes \label{section-other}} |
| |
| 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: |
| |
| \begin{itemize} |
| |
| \item Details go here. |
| |
| \end{itemize} |
| |
| |
| %====================================================================== |
| \section{Porting to Python 2.6} |
| |
| This section lists previously described changes that may require |
| changes to your code: |
| |
| \begin{itemize} |
| |
| \item Everything is all in the details! |
| |
| \end{itemize} |
| |
| |
| %====================================================================== |
| \section{Acknowledgements \label{acks}} |
| |
| The author would like to thank the following people for offering |
| suggestions, corrections and assistance with various drafts of this |
| article: . |
| |
| \end{document} |