1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
****************************
What's New In Python 3.11
****************************
:Release: |release|
:Date: |today|
.. 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:
XXX Describe the transmogrify() function added to the socket
module.
(Contributed by P.Y. Developer in :issue:`12345`.)
This saves the maintainer the effort of going through the Mercurial log
when researching a change.
This article explains the new features in Python 3.11, compared to 3.10.
For full details, see the :ref:`changelog <changelog>`.
.. note::
Prerelease users should be aware that this document is currently in draft
form. It will be updated substantially as Python 3.11 moves towards release,
so it's worth checking back even after reading earlier versions.
Summary -- Release highlights
=============================
.. This section singles out the most important changes in Python 3.11.
Brevity is key.
.. PEP-sized items next.
New Features
============
Other Language Changes
======================
A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
:meth:`contextlib.ExitStack.enter_context` and
:meth:`contextlib.AsyncExitStack.enter_async_context` for objects which do not
support the :term:`context manager` or :term:`asynchronous context manager`
protocols correspondingly.
(Contributed by Serhiy Storchaka in :issue:`44471`.)
* A :exc:`TypeError` is now raised instead of an :exc:`AttributeError` in
:keyword:`with` and :keyword:`async with` statements for objects which do not
support the :term:`context manager` or :term:`asynchronous context manager`
protocols correspondingly.
(Contributed by Serhiy Storchaka in :issue:`12022`.)
New Modules
===========
* None yet.
Improved Modules
================
fractions
---------
Support :PEP:`515`-style initialization of :class:`~fractions.Fraction` from
string. (Contributed by Sergey B Kirpichev in :issue:`44258`.)
math
----
* Add :func:`math.cbrt`: return the cube root of x.
(Contributed by Ajith Ramachandran in :issue:`44357`.)
* The behaviour of two :func:`math.pow` corner cases was changed, for
consistency with the IEEE 754 specification. The operations
``math.pow(0.0, -math.inf)`` and ``math.pow(-0.0, -math.inf)`` now return
``inf``. Previously they raised :exc:`ValueError`. (Contributed by Mark
Dickinson in :issue:`44339`.)
sqlite3
-------
* You can now disable the authorizer by passing :const:`None` to
:meth:`~sqlite3.Connection.set_authorizer`.
(Contributed by Erlend E. Aasland in :issue:`44491`.)
Removed
=======
* :class:`smtpd.MailmanProxy` is now removed as it is unusable without
an external module, ``mailman``. (Contributed by Dong-hee Na in :issue:`35800`.)
Optimizations
=============
* Compiler now optimizes simple C-style formatting with literal format
containing only format codes ``%s``, ``%r`` and ``%a`` and makes it as
fast as corresponding f-string expression.
(Contributed by Serhiy Storchaka in :issue:`28307`.)
* "Zero-cost" exceptions are implemented. The cost of ``try`` statements is
almost eliminated when no exception is raised.
(Contributed by Mark Shannon in :issue:`40222`.)
* Method calls with keywords are now faster due to bytecode
changes which avoid creating bound method instances. Previously, this
optimization was applied only to method calls with purely positional
arguments.
(Contributed by Ken Jin and Mark Shannon in :issue:`26110`, based on ideas
implemented in PyPy.)
* :file:`.pdbrc` is now read with ``'utf-8'`` encoding.
CPython bytecode changes
========================
* Added a new :opcode:`CALL_METHOD_KW` opcode. Calls a method in a similar
fashion as :opcode:`CALL_METHOD`, but also supports keyword arguments. Works
in tandem with :opcode:`LOAD_METHOD`.
Build Changes
=============
Deprecated
==========
Removed
=======
* The :func:`@asyncio.coroutine <asyncio.coroutine>` :term:`decorator` enabling
legacy generator-based coroutines to be compatible with async/await code.
The function has been deprecated since Python 3.8 and the removal was
initially scheduled for Python 3.10. Use :keyword:`async def` instead.
(Contributed by Illia Volochii in :issue:`43216`.)
* :class:`asyncio.coroutines.CoroWrapper` used for wrapping legacy
generator-based coroutine objects in the debug mode.
(Contributed by Illia Volochii in :issue:`43216`.)
Porting to Python 3.11
======================
This section lists previously described changes and other bugfixes
that may require changes to your code.
Changes in the Python API
-------------------------
* Prohibited passing non-:class:`concurrent.futures.ThreadPoolExecutor`
executors to :meth:`loop.set_default_executor` following a deprecation in
Python 3.8.
(Contributed by Illia Volochii in :issue:`43234`.)
C API Changes
=============
New Features
------------
Porting to Python 3.11
----------------------
* The :c:func:`PyType_Ready` function now raises an error if a type is defined
with the :const:`Py_TPFLAGS_HAVE_GC` flag set but has no traverse function
(:c:member:`PyTypeObject.tp_traverse`).
(Contributed by Victor Stinner in :issue:`44263`.)
Deprecated
----------
Removed
-------
* :c:func:`PyFrame_BlockSetup` and :c:func:`PyFrame_BlockPop` have been
removed.
(Contributed by Mark Shannon in :issue:`40222`.)
* Deprecate the following functions to configure the Python initialization:
* :c:func:`PySys_AddWarnOptionUnicode`
* :c:func:`PySys_AddWarnOption`
* :c:func:`PySys_AddXOption`
* :c:func:`PySys_HasWarnOptions`
* :c:func:`Py_SetPath`
* :c:func:`Py_SetProgramName`
* :c:func:`Py_SetPythonHome`
* :c:func:`Py_SetStandardStreamEncoding`
* :c:func:`_Py_SetProgramFullPath`
Use the new :c:type:`PyConfig` API of the :ref:`Python Initialization Configuration
<init-config>` instead (:pep:`587`).
(Contributed by Victor Stinner in :issue:`44113`.)
* The following deprecated functions and methods are removed in the :mod:`gettext`
module: :func:`~gettext.lgettext`, :func:`~gettext.ldgettext`,
:func:`~gettext.lngettext` and :func:`~gettext.ldngettext`.
Function :func:`~gettext.bind_textdomain_codeset`, methods
:meth:`~gettext.NullTranslations.output_charset` and
:meth:`~gettext.NullTranslations.set_output_charset`, and the *codeset*
parameter of functions :func:`~gettext.translation` and
:func:`~gettext.install` are also removed, since they are only used for
the ``l*gettext()`` functions.
(Contributed by Dong-hee Na and Serhiy Storchaka in :issue:`44235`.)
|
