diff options
Diffstat (limited to 'Doc/whatsnew/2.6.rst')
| -rw-r--r-- | Doc/whatsnew/2.6.rst | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst new file mode 100644 index 0000000..b0e731a --- /dev/null +++ b/Doc/whatsnew/2.6.rst @@ -0,0 +1,236 @@ +**************************** + What's New in Python 2.6 +**************************** + +:Author: A.M. Kuchling +:Release: |release| +:Date: |today| + +.. % $Id: whatsnew26.tex 55963 2007-06-13 18:07:49Z guido.van.rossum $ +.. % 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. + +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 mid 2008. + +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. If you want to understand the +complete implementation and design rationale, refer to the PEP for a particular +new feature. + +.. % Compare with previous release in 2 - 3 sentences here. +.. % add hyperlink when the documentation becomes available online. + +.. % ====================================================================== +.. % 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 +.. % ====================================================================== + + +Other Language Changes +====================== + +Here are all of the changes that Python 2.6 makes to the core Python language. + +* An obscure change: when you use the the :func:`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.) + +.. % ====================================================================== + + +Optimizations +------------- + +* 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.) + +The net result of the 2.6 optimizations is that Python 2.6 runs the pystone +benchmark around XX% faster than Python 2.5. + +.. % ====================================================================== + + +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. + +* 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) + + print var[0], var.id # Equivalent + print var[2], var.type # Equivalent + + (Contributed by Raymond Hettinger.) + +* 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. :: + + # Boldface text starting at y=0,x=21 + # and affecting the rest of the line. + stdscr.chgat(0,21, curses.A_BOLD) + + (Contributed by Fabian Kreutz.) + +* The :func:`glob.glob` function can now return Unicode filenames if + a Unicode path was used and Unicode filenames are matched within the directory. + + .. % Patch #1001604 + +* The :mod:`gopherlib` module has been removed. + +* A new function in the :mod:`heapq` module: ``merge(iter1, iter2, ...)`` + takes any number of iterables that return data *in sorted order*, and returns + a new iterator that returns the contents of all the iterators, also in sorted + order. For example:: + + heapq.merge([1, 3, 5, 9], [2, 8, 16]) -> + [1, 2, 3, 5, 8, 9, 16] + + (Contributed by Raymond Hettinger.) + +* A new function in the :mod:`itertools` module: ``izip_longest(iter1, iter2, + ...[, fillvalue])`` makes tuples from each of the elements; if some of the + iterables are shorter than others, the missing values are set to *fillvalue*. + For example:: + + itertools.izip_longest([1,2,3], [1,2,3,4,5]) -> + [(1, 1), (2, 2), (3, 3), (None, 4), (None, 5)] + + (Contributed by Raymond Hettinger.) + +* The :mod:`macfs` module has been removed. This in turn required the + :func:`macostools.touched` function to be removed because it depended on the + :mod:`macfs` module. + + .. % Patch #1490190 + +* 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 + possible values include :const:`UF_IMMUTABLE` to signal the file may not be + changed and :const:`UF_APPEND` to indicate that data can only be appended to the + file. (Contributed by M. Levinson.) + +* The :mod:`rgbimg` module has been removed. + +* 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. (Contributed by Monty Taylor.) + +* The :mod:`test.test_support` module now contains a :func:`EnvironmentVarGuard` + context manager that supports temporarily changing environment variables and + automatically restores them to their old values. (Contributed by Brett Cannon.) + +.. % ====================================================================== +.. % whole new modules get described in \subsections here + +.. % ====================================================================== + + +Build and C API Changes +======================= + +Changes to Python's build process and to the C API include: + +* Detailed changes are listed here. + +.. % ====================================================================== + + +Port-Specific Changes +--------------------- + +Platform-specific changes go here. + +.. % ====================================================================== + + +.. _section-other: + +Other Changes and Fixes +======================= + +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: + +* Details go here. + +.. % ====================================================================== + + +Porting to Python 2.6 +===================== + +This section lists previously described changes that may require changes to your +code: + +* Everything is all in the details! + +.. % ====================================================================== + + +.. _acks: + +Acknowledgements +================ + +The author would like to thank the following people for offering suggestions, +corrections and assistance with various drafts of this article: . + |