diff options
Diffstat (limited to 'Doc/whatsnew/2.6.rst')
| -rw-r--r-- | Doc/whatsnew/2.6.rst | 87 |
1 files changed, 45 insertions, 42 deletions
diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst index 883eb90..af7991d 100644 --- a/Doc/whatsnew/2.6.rst +++ b/Doc/whatsnew/2.6.rst @@ -63,7 +63,7 @@ what it can, adding compatibility functions in a usages that will become unsupported in 3.0. Some significant new packages have been added to the standard library, -such as the :mod:`multiprocessing` and :mod:`jsonlib` modules, but +such as the :mod:`multiprocessing` and :mod:`json` modules, but there aren't many new features that aren't related to Python 3.0 in some way. @@ -623,7 +623,7 @@ versa.) Two other classes, :class:`Pool` and :class:`Manager`, provide higher-level interfaces. :class:`Pool` will create a fixed number of worker processes, and requests can then be distributed to the workers -by calling :meth:`apply` or `apply_async` to add a single request, +by calling :meth:`apply` or :meth:`apply_async` to add a single request, and :meth:`map` or :meth:`map_async` to add a number of requests. The following code uses a :class:`Pool` to spread requests across 5 worker processes and retrieve a list of results:: @@ -977,10 +977,10 @@ sequence of bytes:: bytearray(b'ABC') >>> b = bytearray(u'\u21ef\u3244', 'utf-8') >>> b - bytearray(b'\xe2\x87\xaf \xe3\x89\x84') + bytearray(b'\xe2\x87\xaf\xe3\x89\x84') >>> b[0] = '\xe3' >>> b - bytearray(b'\xe3\x87\xaf \xe3\x89\x84') + bytearray(b'\xe3\x87\xaf\xe3\x89\x84') >>> unicode(str(b), 'utf-8') u'\u31ef \u3244' @@ -1975,7 +1975,7 @@ changes, or look through the Subversion logs for all the details. * A new function in the :mod:`heapq` module, ``merge(iter1, iter2, ...)``, takes any number of iterables returning data in sorted - order, and returns a new iterator that returns the contents of all + order, and returns a new generator that returns the contents of all the iterators, also in sorted order. For example:: heapq.merge([1, 3, 5, 9], [2, 8, 16]) -> @@ -2014,56 +2014,56 @@ changes, or look through the Subversion logs for all the details. 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)] + (1, 1), (2, 2), (3, 3), (None, 4), (None, 5) ``product(iter1, iter2, ..., [repeat=N])`` returns the Cartesian product of the supplied iterables, a set of tuples containing every possible combination of the elements returned from each iterable. :: itertools.product([1,2,3], [4,5,6]) -> - [(1, 4), (1, 5), (1, 6), + (1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), - (3, 4), (3, 5), (3, 6)] + (3, 4), (3, 5), (3, 6) The optional *repeat* keyword argument is used for taking the product of an iterable or a set of iterables with themselves, repeated *N* times. With a single iterable argument, *N*-tuples are returned:: - itertools.product([1,2], repeat=3)) -> - [(1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2), - (2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2)] + itertools.product([1,2], repeat=3) -> + (1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2), + (2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2) With two iterables, *2N*-tuples are returned. :: - itertools(product([1,2], [3,4], repeat=2) -> - [(1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 3), (1, 3, 2, 4), + itertools.product([1,2], [3,4], repeat=2) -> + (1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 3), (1, 3, 2, 4), (1, 4, 1, 3), (1, 4, 1, 4), (1, 4, 2, 3), (1, 4, 2, 4), (2, 3, 1, 3), (2, 3, 1, 4), (2, 3, 2, 3), (2, 3, 2, 4), - (2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 3), (2, 4, 2, 4)] + (2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 3), (2, 4, 2, 4) ``combinations(iterable, r)`` returns sub-sequences of length *r* from the elements of *iterable*. :: itertools.combinations('123', 2) -> - [('1', '2'), ('1', '3'), ('2', '3')] + ('1', '2'), ('1', '3'), ('2', '3') itertools.combinations('123', 3) -> - [('1', '2', '3')] + ('1', '2', '3') itertools.combinations('1234', 3) -> - [('1', '2', '3'), ('1', '2', '4'), ('1', '3', '4'), - ('2', '3', '4')] + ('1', '2', '3'), ('1', '2', '4'), ('1', '3', '4'), + ('2', '3', '4') ``permutations(iter[, r])`` returns all the permutations of length *r* of the iterable's elements. If *r* is not specified, it will default to the number of elements produced by the iterable. :: itertools.permutations([1,2,3,4], 2) -> - [(1, 2), (1, 3), (1, 4), + (1, 2), (1, 3), (1, 4), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (3, 4), - (4, 1), (4, 2), (4, 3)] + (4, 1), (4, 2), (4, 3) ``itertools.chain(*iterables)`` is an existing function in :mod:`itertools` that gained a new constructor in Python 2.6. @@ -2073,7 +2073,7 @@ changes, or look through the Subversion logs for all the details. all the elements of the second, and so on. :: chain.from_iterable([[1,2,3], [4,5,6]]) -> - [1, 2, 3, 4, 5, 6] + 1, 2, 3, 4, 5, 6 (All contributed by Raymond Hettinger.) @@ -2178,7 +2178,7 @@ changes, or look through the Subversion logs for all the details. :const:`UF_APPEND` to indicate that data can only be appended to the file. (Contributed by M. Levinson.) - ``os.closerange(*low*, *high*)`` efficiently closes all file descriptors + ``os.closerange(low, high)`` efficiently closes all file descriptors from *low* to *high*, ignoring any errors and not including *high* itself. This function is now used by the :mod:`subprocess` module to make starting processes faster. (Contributed by Georg Brandl; :issue:`1663329`.) @@ -2311,12 +2311,12 @@ changes, or look through the Subversion logs for all the details. will be ignored, not copied. The :mod:`shutil` module also provides an :func:`ignore_patterns` - function for use with this new parameter. - :func:`ignore_patterns` takes an arbitrary number of glob-style patterns - and will ignore any files and directories that match any of these patterns. - The following example copies a directory tree, but skips both - :file:`.svn` directories and Emacs backup - files, which have names ending with '~':: + function for use with this new parameter. :func:`ignore_patterns` + takes an arbitrary number of glob-style patterns and returns a + callable that will ignore any files and directories that match any + of these patterns. The following example copies a directory tree, + but skips both :file:`.svn` directories and Emacs backup files, + which have names ending with '~':: shutil.copytree('Doc/library', '/tmp/library', ignore=shutil.ignore_patterns('*~', '.svn')) @@ -2523,13 +2523,15 @@ changes, or look through the Subversion logs for all the details. (Contributed by Dwayne Bailey; :issue:`1581073`.) -* The :mod:`threading` module API is being changed to use properties such as - :attr:`daemon` instead of :meth:`setDaemon` and :meth:`isDaemon` methods, and - some methods have been renamed to use underscores instead of camel-case; for - example, the :meth:`activeCount` method is renamed to :meth:`active_count`. - The 2.6 version of the module supports the same properties and renamed - methods, but doesn't remove the old methods. 3.0 also fully supports both - APIs, and a date for the deprecation of the old APIs has not been set yet. +* The :mod:`threading` module API is being changed to use properties + such as :attr:`daemon` instead of :meth:`setDaemon` and + :meth:`isDaemon` methods, and some methods have been renamed to use + underscores instead of camel-case; for example, the + :meth:`activeCount` method is renamed to :meth:`active_count`. Both + the 2.6 and 3.0 versions of the module support the same properties + and renamed methods, but don't remove the old methods. No date has been set + for the deprecation of the old APIs in Python 3.x; the old APIs won't + be removed in any 2.x version. (Carried out by several people, most notably Benjamin Peterson.) The :mod:`threading` module's :class:`Thread` objects @@ -2735,15 +2737,15 @@ of these built-in functions that can be imported when writing The functions in this module currently include: -* ``ascii(*obj*)``: equivalent to :func:`repr`. In Python 3.0, +* ``ascii(obj)``: equivalent to :func:`repr`. In Python 3.0, :func:`repr` will return a Unicode string, while :func:`ascii` will return a pure ASCII bytestring. -* ``filter(*predicate*, *iterable*)``, - ``map(*func*, *iterable1*, ...)``: the 3.0 versions +* ``filter(predicate, iterable)``, + ``map(func, iterable1, ...)``: the 3.0 versions return iterators, unlike the 2.x built-ins which return lists. -* ``hex(*value*)``, ``oct(*value*)``: instead of calling the +* ``hex(value)``, ``oct(value)``: instead of calling the :meth:`__hex__` or :meth:`__oct__` methods, these versions will call the :meth:`__index__` method and convert the result to hexadecimal or octal. :func:`oct` will use the new ``0o`` notation for its @@ -3210,7 +3212,8 @@ that may require changes to your code: Acknowledgements ================ -The author would like to thank the following people for offering suggestions, -corrections and assistance with various drafts of this article: -Georg Brandl, Steve Brown, Nick Coghlan, Jim Jewett, Antoine Pitrou. +The author would like to thank the following people for offering +suggestions, corrections and assistance with various drafts of this +article: Georg Brandl, Steve Brown, Nick Coghlan, Jim Jewett, Kent +Johnson, Chris Lambacher, Antoine Pitrou. |