Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 1 | **************************** |
| 2 | What's New In Python 3.4 |
| 3 | **************************** |
| 4 | |
Georg Brandl | 3b80d34 | 2012-10-28 13:37:54 +0100 | [diff] [blame] | 5 | .. :Author: Someone <email> |
| 6 | (uncomment if there is a principal author) |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 7 | |
| 8 | .. Rules for maintenance: |
| 9 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 10 | * Anyone can add text to this document, but the maintainer reserves the |
| 11 | right to rewrite any additions. In particular, for obscure or esoteric |
| 12 | features, the maintainer may reduce any addition to a simple reference to |
| 13 | the new documentation rather than explaining the feature inline. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 14 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 15 | * While the maintainer will periodically go through Misc/NEWS |
| 16 | and add changes, it's best not to rely on this. We know from experience |
| 17 | that any changes that aren't in the What's New documentation around the |
| 18 | time of the original release will remain largely unknown to the community |
| 19 | for years, even if they're added later. We also know from experience that |
| 20 | other priorities can arise, and the maintainer will run out of time to do |
| 21 | updates - in such cases, end users will be much better served by partial |
| 22 | notifications that at least give a hint about new features to |
| 23 | investigate. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 24 | |
| 25 | * This is not a complete list of every single change; completeness |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 26 | is the purpose of Misc/NEWS. The What's New should focus on changes that |
| 27 | are visible to Python *users* and that *require* a feature release (i.e. |
| 28 | most bug fixes should only be recorded in Misc/NEWS) |
| 29 | |
| 30 | * PEPs should not be marked Final until they have an entry in What's New. |
| 31 | A placeholder entry that is just a section header and a link to the PEP |
| 32 | (e.g ":pep:`397` has been implemented") is acceptable. If a PEP has been |
| 33 | implemented and noted in What's New, don't forget to mark it as Final! |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 34 | |
| 35 | * If you want to draw your new text to the attention of the |
| 36 | maintainer, add 'XXX' to the beginning of the paragraph or |
| 37 | section. |
| 38 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 39 | * It's OK to add just a very brief note about a change. For |
| 40 | example: "The :ref:`~socket.transmogrify()` function was added to the |
| 41 | :mod:`socket` module." The maintainer will research the change and |
| 42 | write the necessary text (if appropriate). The advantage of doing this |
| 43 | is that even if no more descriptive text is ever added, readers will at |
| 44 | least have a notification that the new feature exists and a link to the |
| 45 | relevant documentation. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 46 | |
| 47 | * You can comment out your additions if you like, but it's not |
| 48 | necessary (especially when a final release is some months away). |
| 49 | |
| 50 | * Credit the author of a patch or bugfix. Just the name is |
| 51 | sufficient; the e-mail address isn't necessary. |
| 52 | |
| 53 | * It's helpful to add the bug/patch number as a comment: |
| 54 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 55 | The :ref:`~socket.transmogrify()` function was added to the |
| 56 | :mod:`socket` module. (Contributed by P.Y. Developer in :issue:`12345`.) |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 57 | |
| 58 | This saves the maintainer the effort of going through the Mercurial log |
| 59 | when researching a change. |
| 60 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 61 | * Cross referencing tip: :ref:`mod.attr` will display as ``mod.attr``, |
| 62 | while :ref:`~mod.attr` will display as ``attr``. |
| 63 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 64 | This article explains the new features in Python 3.4, compared to 3.3. |
| 65 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 66 | .. Python 3.4 was released on TBD. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 67 | |
Ezio Melotti | 25bbe5e | 2012-11-17 19:30:48 +0200 | [diff] [blame] | 68 | For full details, see the |
| 69 | `changelog <http://docs.python.org/3.4/whatsnew/changelog.html>`_. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 70 | |
| 71 | .. note:: Prerelease users should be aware that this document is currently in |
| 72 | draft form. It will be updated substantially as Python 3.4 moves towards |
| 73 | release, so it's worth checking back even after reading earlier versions. |
| 74 | |
| 75 | |
| 76 | .. seealso:: |
| 77 | |
Nick Coghlan | 03074fd | 2012-09-30 18:51:53 +0530 | [diff] [blame] | 78 | .. :pep:`4XX` - Python 3.4 Release Schedule |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 79 | |
| 80 | |
| 81 | Summary -- Release highlights |
| 82 | ============================= |
| 83 | |
Kristjan Valur Jonsson | a1e8244 | 2013-03-26 13:56:14 +0000 | [diff] [blame] | 84 | .. This section singles out the most important changes in Python 3.4. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 85 | Brevity is key. |
| 86 | |
| 87 | New syntax features: |
| 88 | |
| 89 | * None yet. |
| 90 | |
| 91 | New library modules: |
| 92 | |
Victor Stinner | 84e33c8 | 2013-06-21 00:31:55 +0200 | [diff] [blame] | 93 | * :mod:`enum`: Implementation of the :pep:`435`. |
Victor Stinner | 4aea4a0 | 2013-09-04 20:30:34 +0200 | [diff] [blame] | 94 | * :mod:`selectors`: High-level and efficient I/O multiplexing, built upon the |
| 95 | :mod:`select` module primitives. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 96 | |
| 97 | New built-in features: |
| 98 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 99 | * :ref:`PEP 442: Safe object finalization <pep-442>`. |
| 100 | * :ref:`PEP 445: Configurable memory allocators <pep-445>`. |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 101 | * :ref:`PEP 446: Make newly created file descriptors non-inheritable <pep-446>`. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 102 | |
| 103 | Implementation improvements: |
| 104 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 105 | * A more efficient :mod:`marshal` format (:issue:`16475`). |
| 106 | * Improve finalization of Python modules to avoid setting their globals |
| 107 | to None, in most cases (:issue:`18214`). |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 108 | |
| 109 | Significantly Improved Library Modules: |
| 110 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 111 | * Single-dispatch generic functions (:pep:`443`) |
| 112 | * SHA-3 (Keccak) support for :mod:`hashlib`. |
| 113 | * TLSv1.1 and TLSv1.2 support for :mod:`ssl`. |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 114 | * :mod:`multiprocessing` now has option to avoid using :func:`os.fork` |
| 115 | on Unix (:issue:`8713`). |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 116 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 117 | Security improvements: |
| 118 | |
Christian Heimes | ad73a9c | 2013-08-10 16:36:18 +0200 | [diff] [blame] | 119 | * command line option for :ref:`isolated mode <using-on-misc-options>`, |
| 120 | :issue:`16499`. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 121 | |
| 122 | Please read on for a comprehensive list of user-facing changes. |
| 123 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 124 | .. _pep-446: |
| 125 | |
| 126 | PEP 446: Make newly created file descriptors non-inheritable |
| 127 | ============================================================ |
| 128 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 129 | The :pep:`446` makes newly created file descriptors :ref:`non-inheritable |
| 130 | <fd_inheritance>`. New functions and methods: |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 131 | |
| 132 | * :func:`os.get_inheritable`, :func:`os.set_inheritable` |
| 133 | * :func:`os.get_handle_inheritable`, :func:`os.set_handle_inheritable` |
| 134 | * :meth:`socket.socket.get_inheritable`, :meth:`socket.socket.set_inheritable` |
| 135 | |
| 136 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 137 | .. _pep-445: |
| 138 | |
| 139 | PEP 445: Add new APIs to customize Python memory allocators |
| 140 | =========================================================== |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 141 | |
Victor Stinner | 0507bf5 | 2013-07-07 02:05:46 +0200 | [diff] [blame] | 142 | The :pep:`445` adds new Application Programming Interfaces (API) to customize |
| 143 | Python memory allocators. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 144 | |
| 145 | |
Antoine Pitrou | 796564c | 2013-07-30 19:59:21 +0200 | [diff] [blame] | 146 | .. _pep-442: |
| 147 | |
| 148 | PEP 442: Safe object finalization |
| 149 | ================================= |
| 150 | |
| 151 | This PEP removes the current limitations and quirks of object finalization. |
| 152 | With it, objects with :meth:`__del__` methods, as well as generators |
| 153 | with :keyword:`finally` clauses, can be finalized when they are part of a |
| 154 | reference cycle. |
| 155 | |
| 156 | .. seealso:: |
| 157 | |
| 158 | :pep:`442` - Safe object finalization |
| 159 | PEP written and implemented by Antoine Pitrou |
| 160 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 161 | |
| 162 | Other Language Changes |
| 163 | ====================== |
| 164 | |
| 165 | Some smaller changes made to the core Python language are: |
| 166 | |
Georg Brandl | 50de850 | 2012-09-30 14:39:18 +0200 | [diff] [blame] | 167 | * Unicode database updated to UCD version 6.2. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 168 | |
R David Murray | 9a2f139 | 2013-06-28 13:31:19 -0400 | [diff] [blame] | 169 | * :func:`min` and :func:`max` now accept a *default* argument that can be used |
| 170 | to specify the value they return if the iterable they are evaluating has no |
| 171 | elements. Contributed by Julian Berman in :issue:`18111`. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 172 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 173 | * Module objects are now :mod:`weakref`'able. |
| 174 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 175 | |
| 176 | New Modules |
| 177 | =========== |
| 178 | |
Charles-François Natali | 243d8d8 | 2013-09-04 19:02:49 +0200 | [diff] [blame] | 179 | selectors |
| 180 | --------- |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 181 | |
Charles-François Natali | 243d8d8 | 2013-09-04 19:02:49 +0200 | [diff] [blame] | 182 | The new :mod:`selectors` module allows high-level and efficient I/O |
| 183 | multiplexing, built upon the :mod:`select` module primitives. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 184 | |
| 185 | |
| 186 | Improved Modules |
| 187 | ================ |
| 188 | |
Antoine Pitrou | d6cbd34 | 2013-08-12 20:48:15 +0200 | [diff] [blame] | 189 | aifc |
| 190 | ---- |
| 191 | |
| 192 | The :meth:`~aifc.getparams` method now returns a namedtuple rather than a |
| 193 | plain tuple. (Contributed by Claudiu Popa in :issue:`17818`.) |
| 194 | |
| 195 | |
| 196 | colorsys |
| 197 | -------- |
| 198 | |
| 199 | The number of digits in the coefficients for the RGB --- YIQ conversions have |
| 200 | been expanded so that they match the FCC NTSC versions. The change in |
| 201 | results should be less than 1% and may better match results found elsewhere. |
| 202 | |
R David Murray | 8e37d5d | 2013-04-13 14:49:48 -0400 | [diff] [blame] | 203 | |
Nick Coghlan | b39fd0c | 2013-05-06 23:59:20 +1000 | [diff] [blame] | 204 | dis |
| 205 | --- |
| 206 | |
| 207 | The :mod:`dis` module is now built around an :class:`Instruction` class that |
| 208 | provides details of individual bytecode operations and a |
| 209 | :func:`get_instructions` iterator that emits the Instruction stream for a |
| 210 | given piece of Python code. The various display tools in the :mod:`dis` |
| 211 | module have been updated to be based on these new components. |
| 212 | |
| 213 | The new :class:`dis.Bytecode` class provides an object-oriented API for |
| 214 | inspecting bytecode, both in human-readable form and for iterating over |
| 215 | instructions. |
| 216 | |
| 217 | (Contributed by Nick Coghlan, Ryan Kelly and Thomas Kluyver in :issue:`11816`) |
| 218 | |
Antoine Pitrou | d6cbd34 | 2013-08-12 20:48:15 +0200 | [diff] [blame] | 219 | |
R David Murray | 5a9d706 | 2012-11-21 15:09:21 -0500 | [diff] [blame] | 220 | doctest |
| 221 | ------- |
| 222 | |
R David Murray | 5707d50 | 2013-06-23 14:24:13 -0400 | [diff] [blame] | 223 | Added :data:`~doctest.FAIL_FAST` flag to halt test running as soon as the first |
| 224 | failure is detected. (Contributed by R. David Murray and Daniel Urban in |
| 225 | :issue:`16522`.) |
| 226 | |
| 227 | Updated the doctest command line interface to use :mod:`argparse`, and added |
| 228 | ``-o`` and ``-f`` options to the interface. ``-o`` allows doctest options to |
| 229 | be specified on the command line, and ``-f`` is a shorthand for ``-o |
| 230 | FAIL_FAST`` (to parallel the similar option supported by the :mod:`unittest` |
| 231 | CLI). (Contributed by R. David Murray in :issue:`11390`.) |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 232 | |
R David Murray | 8e37d5d | 2013-04-13 14:49:48 -0400 | [diff] [blame] | 233 | |
R David Murray | bb17d2b | 2013-08-09 16:15:28 -0400 | [diff] [blame] | 234 | email |
| 235 | ----- |
| 236 | |
| 237 | :meth:`~email.message.Message.as_string` now accepts a *policy* argument to |
| 238 | override the default policy of the message when generating a string |
| 239 | representation of it. This means that ``as_string`` can now be used in more |
| 240 | circumstances, instead of having to create and use a :mod:`~email.generator` in |
| 241 | order to pass formatting parameters to its ``flatten`` method. |
| 242 | |
| 243 | New method :meth:`~email.message.Message.as_bytes` added to produce a bytes |
| 244 | representation of the message in a fashion similar to how ``as_string`` |
| 245 | produces a string representation. It does not accept the *maxheaderlen* |
| 246 | argument, but does accept the *unixfrom* and *policy* arguments. The |
| 247 | :class:`~email.message.Message` :meth:`~email.message.Message.__bytes__` method |
| 248 | calls it, meaning that ``bytes(mymsg)`` will now produce the intuitive |
| 249 | result: a bytes object containing the fully formatted message. |
| 250 | |
| 251 | (Contributed by R. David Murray in :issue:`18600`.) |
| 252 | |
| 253 | |
Victor Stinner | 854ffcb | 2013-06-21 00:36:30 +0200 | [diff] [blame] | 254 | functools |
| 255 | --------- |
| 256 | |
| 257 | New :func:`functools.singledispatch` decorator: see the :pep:`443`. |
| 258 | |
Nick Coghlan | e8c45d6 | 2013-07-28 20:00:01 +1000 | [diff] [blame] | 259 | |
Antoine Pitrou | d6cbd34 | 2013-08-12 20:48:15 +0200 | [diff] [blame] | 260 | inspect |
| 261 | ------- |
| 262 | |
| 263 | :func:`~inspect.unwrap` makes it easy to unravel wrapper function chains |
| 264 | created by :func:`functools.wraps` (and any other API that sets the |
| 265 | ``__wrapped__`` attribute on a wrapper function). |
| 266 | |
| 267 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 268 | mmap |
| 269 | ---- |
| 270 | |
| 271 | mmap objects can now be weakref'ed. |
| 272 | |
| 273 | (Contributed by Valerie Lambert in :issue:`4885`.) |
| 274 | |
| 275 | |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 276 | multiprocessing |
| 277 | --------------- |
| 278 | |
| 279 | On Unix two new *start methods* have been added for starting processes |
| 280 | using :mod:`multiprocessing`. These make the mixing of processes with |
| 281 | threads more robust. See :issue:`8713`. |
| 282 | |
| 283 | Also, except when using the old *fork* start method, child processes |
| 284 | will no longer inherit unneeded handles/file descriptors from their parents. |
| 285 | |
| 286 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 287 | os |
| 288 | -- |
| 289 | |
| 290 | New functions to get and set the `inheritable flag <fd_inheritance>`_ of a file |
| 291 | descriptors or a Windows handle: |
| 292 | |
| 293 | * :func:`os.get_inheritable`, :func:`os.set_inheritable` |
| 294 | * :func:`os.get_handle_inheritable`, :func:`os.set_handle_inheritable` |
| 295 | |
| 296 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 297 | poplib |
| 298 | ------ |
| 299 | |
| 300 | New :meth:`~poplib.POP3.stls` method to switch a clear-text POP3 session into |
| 301 | an encrypted POP3 session. |
| 302 | |
| 303 | New :meth:`~poplib.POP3.capa` method to query the capabilities advertised by the |
| 304 | POP3 server. |
| 305 | |
| 306 | (Contributed by Lorenzo Catucci in :issue:`4473`.) |
| 307 | |
| 308 | |
R David Murray | 8e37d5d | 2013-04-13 14:49:48 -0400 | [diff] [blame] | 309 | smtplib |
| 310 | ------- |
| 311 | |
R David Murray | 8a34596 | 2013-04-14 06:46:35 -0400 | [diff] [blame] | 312 | :exc:`~smtplib.SMTPException` is now a subclass of :exc:`OSError`, which allows |
R David Murray | 8e37d5d | 2013-04-13 14:49:48 -0400 | [diff] [blame] | 313 | both socket level errors and SMTP protocol level errors to be caught in one |
| 314 | try/except statement by code that only cares whether or not an error occurred. |
| 315 | (:issue:`2118`). |
| 316 | |
Antoine Pitrou | d6cbd34 | 2013-08-12 20:48:15 +0200 | [diff] [blame] | 317 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 318 | socket |
| 319 | ------ |
| 320 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 321 | Socket objects have new methods to get or set their :ref:`inheritable flag |
| 322 | <fd_inheritance>`: |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 323 | |
| 324 | * :meth:`socket.socket.get_inheritable`, :meth:`socket.socket.set_inheritable` |
| 325 | |
Eli Bendersky | 34567ec | 2013-08-31 15:18:48 -0700 | [diff] [blame] | 326 | The ``socket.AF_*`` and ``socket.SOCK_*`` constants are enumeration values, |
| 327 | using the new :mod:`enum` module. This allows descriptive reporting during |
| 328 | debugging, instead of seeing integer "magic numbers". |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 329 | |
Christian Heimes | 24cd4cf | 2013-06-22 19:31:58 +0200 | [diff] [blame] | 330 | ssl |
| 331 | --- |
| 332 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 333 | TLSv1.1 and TLSv1.2 support. |
Christian Heimes | 70833a8 | 2013-06-22 19:34:17 +0200 | [diff] [blame] | 334 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 335 | (Contributed by Michele Orrù and Antoine Pitrou in :issue:`16692`) |
Christian Heimes | 24cd4cf | 2013-06-22 19:31:58 +0200 | [diff] [blame] | 336 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 337 | * New diagnostic functions :func:`~ssl.get_default_verify_paths`, |
| 338 | :meth:`~ssl.SSLContext.cert_store_stats` and |
| 339 | :meth:`~ssl.SSLContext.get_ca_certs` |
| 340 | |
| 341 | * Add :func:`ssl.enum_cert_store` to retrieve certificates and CRL from Windows' |
| 342 | cert store. |
Christian Heimes | 24cd4cf | 2013-06-22 19:31:58 +0200 | [diff] [blame] | 343 | |
| 344 | (Contributed by Christian Heimes in :issue:`18143`, :issue:`18147` and |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 345 | :issue:`17134`.) |
| 346 | |
| 347 | Support for server-side SNI using the new |
| 348 | :meth:`ssl.SSLContext.set_servername_callback` method. |
| 349 | |
| 350 | (Contributed by Daniel Black in :issue:`8109`.) |
| 351 | |
| 352 | |
Antoine Pitrou | d6cbd34 | 2013-08-12 20:48:15 +0200 | [diff] [blame] | 353 | stat |
| 354 | ---- |
| 355 | |
| 356 | The :mod:`stat` module is now backed by a C implementation in :mod:`_stat`. A C |
| 357 | implementation is required as most of the values aren't standardized and |
| 358 | platform-dependent. (Contributed by Christian Heimes in :issue:`11016`.) |
| 359 | |
| 360 | The module supports new file types: door, event port and whiteout. |
| 361 | |
| 362 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 363 | struct |
| 364 | ------ |
| 365 | |
| 366 | Streaming struct unpacking using :func:`struct.iter_unpack`. |
| 367 | |
| 368 | (Contributed by Antoine Pitrou in :issue:`17804`.) |
| 369 | |
| 370 | |
Serhiy Storchaka | e06a896 | 2013-09-04 00:43:03 +0300 | [diff] [blame] | 371 | sunau |
| 372 | ----- |
| 373 | |
| 374 | The :meth:`~sunau.getparams` method now returns a namedtuple rather than a |
| 375 | plain tuple. (Contributed by Claudiu Popa in :issue:`18901`.) |
| 376 | |
Serhiy Storchaka | 34d2013 | 2013-09-05 17:01:53 +0300 | [diff] [blame] | 377 | :meth:`sunau.open` now supports the context manager protocol (:issue:`18878`). |
| 378 | |
Serhiy Storchaka | e06a896 | 2013-09-04 00:43:03 +0300 | [diff] [blame] | 379 | |
Andrew Kuchling | 173a157 | 2013-09-15 18:15:56 -0400 | [diff] [blame^] | 380 | traceback |
| 381 | --------- |
| 382 | |
| 383 | A new :func:`traceback.clear_frames` function takes a traceback object |
| 384 | and clears the local variables in all of the frames it references, |
| 385 | reducing the amount of memory consumed (:issue:`1565525`). |
| 386 | |
| 387 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 388 | urllib |
| 389 | ------ |
| 390 | |
| 391 | Add support.for ``data:`` URLs in :mod:`urllib.request`. |
| 392 | |
| 393 | (Contributed by Mathias Panzenböck in :issue:`16423`.) |
| 394 | |
| 395 | |
| 396 | unittest |
| 397 | -------- |
| 398 | |
| 399 | Support for easy dynamically-generated subtests using the |
| 400 | :meth:`~unittest.TestCase.subTest` context manager. |
| 401 | |
| 402 | (Contributed by Antoine Pitrou in :issue:`16997`.) |
| 403 | |
R David Murray | 8e37d5d | 2013-04-13 14:49:48 -0400 | [diff] [blame] | 404 | |
R David Murray | 671cd32 | 2013-04-10 12:31:43 -0400 | [diff] [blame] | 405 | wave |
| 406 | ---- |
| 407 | |
| 408 | The :meth:`~wave.getparams` method now returns a namedtuple rather than a |
| 409 | plain tuple. (Contributed by Claudiu Popa in :issue:`17487`.) |
| 410 | |
R David Murray | c91d5ee | 2013-07-31 13:46:08 -0400 | [diff] [blame] | 411 | :meth:`wave.open` now supports the context manager protocol. (Contributed |
| 412 | by Claudiu Popa in :issue:`17616`.) |
| 413 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 414 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 415 | weakref |
| 416 | ------- |
| 417 | |
| 418 | New :class:`~weakref.WeakMethod` class simulates weak references to bound |
| 419 | methods. |
| 420 | |
| 421 | (Contributed by Antoine Pitrou in :issue:`14631`.) |
| 422 | |
| 423 | |
| 424 | xml.etree |
| 425 | --------- |
| 426 | |
| 427 | Add an event-driven parser for non-blocking applications, |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 428 | :class:`~xml.etree.ElementTree.XMLPullParser`. |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 429 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 430 | (Contributed by Antoine Pitrou in :issue:`17741`.) |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 431 | |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 432 | Other improvements |
| 433 | ================== |
| 434 | |
| 435 | Tab-completion is now enabled by default in the interactive interpreter. |
| 436 | |
| 437 | (Contributed by Antoine Pitrou and Éric Araujo in :issue:`5845`.) |
| 438 | |
Eli Bendersky | 96d848a | 2013-09-06 06:55:58 -0700 | [diff] [blame] | 439 | Python invocation changes |
| 440 | ========================= |
| 441 | |
| 442 | Invoking the Python interpreter with ``--version`` now outputs the version to |
| 443 | standard output instead of standard error (:issue:`18338`). Similar changes |
| 444 | were made to :mod:`argparse` (:issue:`18920`) and other modules that have |
| 445 | script-like invocation capabilities (:issue:`18922`). |
Antoine Pitrou | f89aa9a | 2013-08-12 20:46:47 +0200 | [diff] [blame] | 446 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 447 | Optimizations |
| 448 | ============= |
| 449 | |
| 450 | Major performance enhancements have been added: |
| 451 | |
Victor Stinner | e64322e | 2012-10-30 23:12:47 +0100 | [diff] [blame] | 452 | * The UTF-32 decoder is now 3x to 4x faster. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 453 | |
Raymond Hettinger | c301b55 | 2013-08-19 09:12:20 -0700 | [diff] [blame] | 454 | * The cost of hash collisions for sets is now reduced. Each hash table |
Raymond Hettinger | 8408dc5 | 2013-09-15 14:57:15 -0700 | [diff] [blame] | 455 | probe now checks a series of consecutive, adjacent key/hash pairs before |
| 456 | continuing to make random probes through the hash table. This exploits |
| 457 | cache locality to make collision resolution less expensive. |
| 458 | |
| 459 | The collision resolution scheme can be described as a hybrid of linear |
| 460 | probing and open addressing. The number of additional linear probes |
| 461 | defaults to nine. This can be changed at compile-time by defining |
| 462 | LINEAR_PROBES to be any value. Set LINEAR_PROBES=0 to turn-off |
| 463 | linear probing entirely. |
Raymond Hettinger | c301b55 | 2013-08-19 09:12:20 -0700 | [diff] [blame] | 464 | |
Andrew Kuchling | 13aa781 | 2013-08-19 13:07:18 -0400 | [diff] [blame] | 465 | (Contributed by Raymond Hettinger in :issue"`18771`.) |
Raymond Hettinger | c301b55 | 2013-08-19 09:12:20 -0700 | [diff] [blame] | 466 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 467 | |
| 468 | Build and C API Changes |
| 469 | ======================= |
| 470 | |
| 471 | Changes to Python's build process and to the C API include: |
| 472 | |
| 473 | * None yet. |
| 474 | |
| 475 | |
| 476 | Deprecated |
| 477 | ========== |
| 478 | |
| 479 | Unsupported Operating Systems |
| 480 | ----------------------------- |
| 481 | |
Victor Stinner | f3fd13b | 2013-08-04 10:30:57 +0200 | [diff] [blame] | 482 | * OS/2 |
Victor Stinner | f3fd13b | 2013-08-04 10:30:57 +0200 | [diff] [blame] | 483 | * Windows 2000 |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 484 | |
| 485 | |
| 486 | Deprecated Python modules, functions and methods |
| 487 | ------------------------------------------------ |
| 488 | |
Terry Jan Reedy | 2b6c26e | 2013-03-21 19:36:26 -0400 | [diff] [blame] | 489 | * :meth:`difflib.SequenceMatcher.isbjunk` and |
Andrew Kuchling | 0d0813a | 2013-06-15 13:29:09 -0400 | [diff] [blame] | 490 | :meth:`difflib.SequenceMatcher.isbpopular` were removed: use ``x in sm.bjunk`` and |
| 491 | ``x in sm.bpopular``, where *sm* is a :class:`~difflib.SequenceMatcher` object. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 492 | |
Brett Cannon | 82b3d6a | 2013-06-14 22:37:11 -0400 | [diff] [blame] | 493 | * :func:`importlib.util.module_for_loader` is pending deprecation. Using |
| 494 | :func:`importlib.util.module_to_load` and |
| 495 | :meth:`importlib.abc.Loader.init_module_attrs` allows subclasses of a loader |
| 496 | to more easily customize module loading. |
| 497 | |
Brett Cannon | e4f41de | 2013-06-16 13:13:40 -0400 | [diff] [blame] | 498 | * The :mod:`imp` module is pending deprecation. To keep compatibility with |
| 499 | Python 2/3 code bases, the module's removal is currently not scheduled. |
| 500 | |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 501 | |
| 502 | Deprecated functions and types of the C API |
| 503 | ------------------------------------------- |
| 504 | |
| 505 | * None yet. |
| 506 | |
| 507 | |
| 508 | Deprecated features |
| 509 | ------------------- |
| 510 | |
Brett Cannon | 82b3d6a | 2013-06-14 22:37:11 -0400 | [diff] [blame] | 511 | * None yet. |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 512 | |
| 513 | |
Benjamin Peterson | 88f3b23 | 2012-10-04 12:45:10 -0400 | [diff] [blame] | 514 | Porting to Python 3.4 |
Georg Brandl | b80f511 | 2012-09-30 09:11:58 +0200 | [diff] [blame] | 515 | ===================== |
| 516 | |
| 517 | This section lists previously described changes and other bugfixes |
| 518 | that may require changes to your code. |
| 519 | |
Brett Cannon | 777622b | 2013-04-09 17:03:10 -0400 | [diff] [blame] | 520 | * The ABCs defined in :mod:`importlib.abc` now either raise the appropriate |
| 521 | exception or return a default value instead of raising |
| 522 | :exc:`NotImplementedError` blindly. This will only affect code calling |
| 523 | :func:`super` and falling through all the way to the ABCs. For compatibility, |
| 524 | catch both :exc:`NotImplementedError` or the appropriate exception as needed. |
Brett Cannon | 4c14b5d | 2013-05-04 13:56:58 -0400 | [diff] [blame] | 525 | |
| 526 | * The module type now initializes the :attr:`__package__` and :attr:`__loader__` |
| 527 | attributes to ``None`` by default. To determine if these attributes were set |
| 528 | in a backwards-compatible fashion, use e.g. |
Brett Cannon | 3dc48d6 | 2013-05-28 18:35:54 -0400 | [diff] [blame] | 529 | ``getattr(module, '__loader__', None) is not None``. |
| 530 | |
| 531 | * :meth:`importlib.util.module_for_loader` now sets ``__loader__`` and |
| 532 | ``__package__`` unconditionally to properly support reloading. If this is not |
| 533 | desired then you will need to set these attributes manually. You can use |
Brett Cannon | 028d512 | 2013-05-31 18:02:11 -0400 | [diff] [blame] | 534 | :func:`importlib.util.module_to_load` for module management. |
Brett Cannon | 3e0651b | 2013-05-31 23:18:39 -0400 | [diff] [blame] | 535 | |
| 536 | * Import now resets relevant attributes (e.g. ``__name__``, ``__loader__``, |
| 537 | ``__package__``, ``__file__``, ``__cached__``) unconditionally when reloading. |
| 538 | |
| 539 | * Frozen packages no longer set ``__path__`` to a list containg the package name |
| 540 | but an empty list instead. Determing if a module is a package should be done |
| 541 | using ``hasattr(module, '__path__')``. |
Brett Cannon | 8f5ac51 | 2013-06-12 23:29:18 -0400 | [diff] [blame] | 542 | |
| 543 | * :c:func:`PyErr_SetImportError` now sets :exc:`TypeError` when its **msg** |
Brett Cannon | 82da888 | 2013-07-04 17:48:16 -0400 | [diff] [blame] | 544 | argument is not set. Previously only ``NULL`` was returned with no exception |
| 545 | set. |
Brett Cannon | 33915eb | 2013-06-14 18:33:00 -0400 | [diff] [blame] | 546 | |
| 547 | * :func:`py_compile.compile` now raises :exc:`FileExistsError` if the file path |
| 548 | it would write to is a symlink or a non-regular file. This is to act as a |
| 549 | warning that import will overwrite those files with a regular file regardless |
| 550 | of what type of file path they were originally. |
Brett Cannon | f4375ef | 2013-06-16 18:05:54 -0400 | [diff] [blame] | 551 | |
| 552 | * :meth:`importlib.abc.SourceLoader.get_source` no longer raises |
| 553 | :exc:`ImportError` when the source code being loaded triggers a |
| 554 | :exc:`SyntaxError` or :exc:`UnicodeDecodeError`. As :exc:`ImportError` is |
| 555 | meant to be raised only when source code cannot be found but it should, it was |
| 556 | felt to be over-reaching/overloading of that meaning when the source code is |
| 557 | found but improperly structured. If you were catching ImportError before and |
| 558 | wish to continue to ignore syntax or decoding issues, catch all three |
Victor Stinner | 84e33c8 | 2013-06-21 00:31:55 +0200 | [diff] [blame] | 559 | exceptions now. |
Nick Coghlan | 24c05bc | 2013-07-15 21:13:08 +1000 | [diff] [blame] | 560 | |
| 561 | * :func:`functools.update_wrapper` and :func:`functools.wraps` now correctly |
| 562 | set the ``__wrapped__`` attribute even if the wrapped function had a |
| 563 | wrapped attribute set. This means ``__wrapped__`` attributes now correctly |
| 564 | link a stack of decorated functions rather than every ``__wrapped__`` |
| 565 | attribute in the chain referring to the innermost function. Introspection |
Nick Coghlan | e8c45d6 | 2013-07-28 20:00:01 +1000 | [diff] [blame] | 566 | libraries that assumed the previous behaviour was intentional can use |
| 567 | :func:`inspect.unwrap` to gain equivalent behaviour. |