Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 1 | **************************** |
Raymond Hettinger | f558ddd | 2009-06-28 21:37:08 +0000 | [diff] [blame] | 2 | What's New In Python 3.2 |
Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 3 | **************************** |
| 4 | |
| 5 | :Author: Raymond Hettinger |
| 6 | :Release: |release| |
| 7 | :Date: |today| |
| 8 | |
| 9 | .. $Id$ |
| 10 | Rules for maintenance: |
| 11 | |
| 12 | * Anyone can add text to this document. Do not spend very much time |
| 13 | on the wording of your changes, because your text will probably |
| 14 | get rewritten to some degree. |
| 15 | |
| 16 | * The maintainer will go through Misc/NEWS periodically and add |
| 17 | changes; it's therefore more important to add your changes to |
| 18 | Misc/NEWS than to this file. |
| 19 | |
| 20 | * This is not a complete list of every single change; completeness |
| 21 | is the purpose of Misc/NEWS. Some changes I consider too small |
| 22 | or esoteric to include. If such a change is added to the text, |
| 23 | I'll just remove it. (This is another reason you shouldn't spend |
| 24 | too much time on writing your addition.) |
| 25 | |
| 26 | * If you want to draw your new text to the attention of the |
| 27 | maintainer, add 'XXX' to the beginning of the paragraph or |
| 28 | section. |
| 29 | |
| 30 | * It's OK to just add a fragmentary note about a change. For |
| 31 | example: "XXX Describe the transmogrify() function added to the |
| 32 | socket module." The maintainer will research the change and |
| 33 | write the necessary text. |
| 34 | |
| 35 | * You can comment out your additions if you like, but it's not |
| 36 | necessary (especially when a final release is some months away). |
| 37 | |
| 38 | * Credit the author of a patch or bugfix. Just the name is |
| 39 | sufficient; the e-mail address isn't necessary. |
| 40 | |
| 41 | * It's helpful to add the bug/patch number as a comment: |
| 42 | |
| 43 | % Patch 12345 |
| 44 | XXX Describe the transmogrify() function added to the socket |
| 45 | module. |
| 46 | (Contributed by P.Y. Developer.) |
| 47 | |
| 48 | This saves the maintainer the effort of going through the SVN log |
| 49 | when researching a change. |
| 50 | |
| 51 | This article explains the new features in Python 3.2, compared to 3.1. |
| 52 | |
| 53 | |
| 54 | PEP XXX: Stub |
| 55 | ============= |
| 56 | |
| 57 | |
| 58 | Other Language Changes |
| 59 | ====================== |
| 60 | |
| 61 | Some smaller changes made to the core Python language are: |
| 62 | |
| 63 | * Stub |
| 64 | |
| 65 | |
| 66 | New, Improved, and Deprecated Modules |
| 67 | ===================================== |
| 68 | |
Raymond Hettinger | f558ddd | 2009-06-28 21:37:08 +0000 | [diff] [blame] | 69 | * The previously deprecated :func:`string.maketrans` function has been |
| 70 | removed in favor of the static methods, :meth:`bytes.maketrans` and |
| 71 | :meth:`bytearray.maketrans`. This change solves the confusion around which |
| 72 | types were supported by the :mod:`string` module. Now, :class:`str`, |
| 73 | :class:`bytes`, and :class:`bytearray` each have their own **maketrans** and |
| 74 | **translate** methods with intermediate translation tables of the |
| 75 | appropriate type. |
Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 76 | |
Raymond Hettinger | f558ddd | 2009-06-28 21:37:08 +0000 | [diff] [blame] | 77 | (Contributed by Georg Brandl; :issue:`5675`.) |
| 78 | |
| 79 | * The previously deprecated :func:`contextlib.nested` function has been |
| 80 | removed in favor of a plain :keyword:`with` statement which can |
| 81 | accept multiple context managers. The latter technique is faster |
| 82 | (because it is built-in), and it does a better job finalizing multiple |
| 83 | context managers when one of them raises an exception. |
| 84 | |
| 85 | (Contributed by Georg Brandl and Mattias Brändström; |
| 86 | `appspot issue 53094 <http://codereview.appspot.com/53094>`_.) |
Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 87 | |
Georg Brandl | 5e73a81 | 2010-04-22 07:02:51 +0000 | [diff] [blame] | 88 | * The :func:`shutil.copytree` function has two new options: |
Tarek Ziadé | 7aa6da0 | 2010-04-20 09:13:23 +0000 | [diff] [blame] | 89 | |
Georg Brandl | 5e73a81 | 2010-04-22 07:02:51 +0000 | [diff] [blame] | 90 | * *ignore_dangling_symlinks*: when ``symlinks=False`` (meaning that the |
| 91 | function copies the file pointed to by the symlink, not the symlink |
| 92 | itself) this option will silence the error thrown if the file doesn't |
| 93 | exist. |
Tarek Ziadé | 7aa6da0 | 2010-04-20 09:13:23 +0000 | [diff] [blame] | 94 | |
Georg Brandl | 5e73a81 | 2010-04-22 07:02:51 +0000 | [diff] [blame] | 95 | * *copy_function*: a callable that will be used to copy files. |
Tarek Ziadé | 7aa6da0 | 2010-04-20 09:13:23 +0000 | [diff] [blame] | 96 | :func:`shutil.copy2` is used by default. |
| 97 | |
Georg Brandl | 5e73a81 | 2010-04-22 07:02:51 +0000 | [diff] [blame] | 98 | (Contributed by Tarek Ziade.) |
Tarek Ziadé | 7aa6da0 | 2010-04-20 09:13:23 +0000 | [diff] [blame] | 99 | |
Antoine Pitrou | d42bc51 | 2009-11-10 23:18:31 +0000 | [diff] [blame] | 100 | Multi-threading |
| 101 | =============== |
| 102 | |
| 103 | * The mechanism for serializing execution of concurrently running Python |
| 104 | threads (generally known as the GIL or Global Interpreter Lock) has been |
| 105 | rewritten. Among the objectives were more predictable switching intervals |
| 106 | and reduced overhead due to lock contention and the number of ensuing |
| 107 | system calls. The notion of a "check interval" to allow thread switches |
| 108 | has been abandoned and replaced by an absolute duration expressed in |
| 109 | seconds. This parameter is tunable through :func:`sys.setswitchinterval()`. |
| 110 | It currently defaults to 5 milliseconds. |
| 111 | |
| 112 | Additional details about the implementation can be read from a `python-dev |
| 113 | mailing-list message |
| 114 | <http://mail.python.org/pipermail/python-dev/2009-October/093321.html>`_ |
| 115 | (however, "priority requests" as exposed in this message have not been |
| 116 | kept for inclusion). |
| 117 | |
Georg Brandl | 5e73a81 | 2010-04-22 07:02:51 +0000 | [diff] [blame] | 118 | (Contributed by Antoine Pitrou.) |
Antoine Pitrou | d42bc51 | 2009-11-10 23:18:31 +0000 | [diff] [blame] | 119 | |
Antoine Pitrou | 5bab508 | 2009-11-13 22:58:45 +0000 | [diff] [blame] | 120 | * Recursive locks (created with the :func:`threading.RLock` API) now benefit |
| 121 | from a C implementation which makes them as fast as regular locks, and |
| 122 | between 10x and 15x faster than their previous pure Python implementation. |
| 123 | |
| 124 | (Contributed by Antoine Pitrou; :issue:`3001`.) |
| 125 | |
Antoine Pitrou | e95a9ff | 2010-05-04 23:31:41 +0000 | [diff] [blame^] | 126 | * Regular and recursive locks now accept an optional *timeout* argument |
| 127 | to their ``acquire`` method. (Contributed by Antoine Pitrou; :issue:`7316`) |
| 128 | Similarly, :meth:`threading.Semaphore.acquire` also gains a *timeout* |
| 129 | argument. (Contributed by Torsten Landschoff; :issue:`850728`.) |
| 130 | |
Antoine Pitrou | d42bc51 | 2009-11-10 23:18:31 +0000 | [diff] [blame] | 131 | |
Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 132 | Optimizations |
| 133 | ============= |
| 134 | |
| 135 | Major performance enhancements have been added: |
| 136 | |
| 137 | * Stub |
| 138 | |
| 139 | IDLE |
| 140 | ==== |
| 141 | |
| 142 | * Stub |
| 143 | |
| 144 | |
| 145 | Build and C API Changes |
| 146 | ======================= |
| 147 | |
| 148 | Changes to Python's build process and to the C API include: |
| 149 | |
| 150 | * Stub |
| 151 | |
| 152 | |
Raymond Hettinger | f558ddd | 2009-06-28 21:37:08 +0000 | [diff] [blame] | 153 | Porting to Python 3.2 |
Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 154 | ===================== |
| 155 | |
| 156 | This section lists previously described changes and other bugfixes |
| 157 | that may require changes to your code: |
| 158 | |
Victor Stinner | dcb2403 | 2010-04-22 12:08:36 +0000 | [diff] [blame] | 159 | * bytearray objects cannot be used anymore as filenames: convert them to bytes |
| 160 | |
Raymond Hettinger | 6e6565b | 2009-06-28 20:56:11 +0000 | [diff] [blame] | 161 | * Stub |