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
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
|
****************************
What's New In Python 3.13
****************************
:Editor: TBD
.. 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 issue number as a comment:
XXX Describe the transmogrify() function added to the socket
module.
(Contributed by P.Y. Developer in :gh:`12345`.)
This saves the maintainer the effort of going through the VCS log
when researching a change.
This article explains the new features in Python 3.13, compared to 3.12.
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 3.13 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 3.13.
Brevity is key.
.. PEP-sized items next.
New Features
============
Other Language Changes
======================
* Allow the *count* argument of :meth:`str.replace` to be a keyword.
(Contributed by Hugo van Kemenade in :gh:`106487`.)
* Compiler now strip indents from docstrings.
This will reduce the size of :term:`bytecode cache <bytecode>` (e.g. ``.pyc`` file).
For example, cache file size for ``sqlalchemy.orm.session`` in SQLAlchemy 2.0
is reduced by about 5%.
This change will affect tools using docstrings, like :mod:`doctest`.
(Contributed by Inada Naoki in :gh:`81283`.)
* The :func:`compile` built-in can now accept a new flag,
``ast.PyCF_OPTIMIZED_AST``, which is similar to ``ast.PyCF_ONLY_AST``
except that the returned ``AST`` is optimized according to the value
of the ``optimize`` argument.
(Contributed by Irit Katriel in :gh:`108113`).
* :mod:`multiprocessing`, :mod:`concurrent.futures`, :mod:`compileall`:
Replace :func:`os.cpu_count` with :func:`os.process_cpu_count` to select the
default number of worker threads and processes. Get the CPU affinity
if supported.
(Contributed by Victor Stinner in :gh:`109649`.)
New Modules
===========
* None yet.
Improved Modules
================
ast
---
* :func:`ast.parse` now accepts an optional argument ``optimize``
which is passed on to the :func:`compile` built-in. This makes it
possible to obtain an optimized ``AST``.
(Contributed by Irit Katriel in :gh:`108113`).
array
-----
* Add ``'w'`` type code (``Py_UCS4``) that can be used for Unicode strings.
It can be used instead of ``'u'`` type code, which is deprecated.
(Contributed by Inada Naoki in :gh:`80480`.)
copy
----
* Add :func:`copy.replace` function which allows to create a modified copy of
an object, which is especially useful for immutable objects.
It supports named tuples created with the factory function
:func:`collections.namedtuple`, :class:`~dataclasses.dataclass` instances,
various :mod:`datetime` objects, :class:`~inspect.Signature` objects,
:class:`~inspect.Parameter` objects, :ref:`code object <code-objects>`, and
any user classes which define the :meth:`!__replace__` method.
(Contributed by Serhiy Storchaka in :gh:`108751`.)
dbm
---
* Add :meth:`dbm.gnu.gdbm.clear` and :meth:`dbm.ndbm.ndbm.clear` methods that remove all items
from the database.
(Contributed by Donghee Na in :gh:`107122`.)
doctest
-------
* The :meth:`doctest.DocTestRunner.run` method now counts the number of skipped
tests. Add :attr:`doctest.DocTestRunner.skips` and
:attr:`doctest.TestResults.skipped` attributes.
(Contributed by Victor Stinner in :gh:`108794`.)
io
--
The :class:`io.IOBase` finalizer now logs the ``close()`` method errors with
:data:`sys.unraisablehook`. Previously, errors were ignored silently by default,
and only logged in :ref:`Python Development Mode <devmode>` or on :ref:`Python
built on debug mode <debug-build>`.
(Contributed by Victor Stinner in :gh:`62948`.)
opcode
------
* Move ``opcode.ENABLE_SPECIALIZATION`` to ``_opcode.ENABLE_SPECIALIZATION``.
This field was added in 3.12, it was never documented and is not intended for
external usage. (Contributed by Irit Katriel in :gh:`105481`.)
* Removed ``opcode.is_pseudo``, ``opcode.MIN_PSEUDO_OPCODE`` and
``opcode.MAX_PSEUDO_OPCODE``, which were added in 3.12, were never
documented or exposed through ``dis``, and were not intended to be
used externally.
os
--
* Add :func:`os.process_cpu_count` function to get the number of logical CPUs
usable by the calling thread of the current process.
(Contributed by Victor Stinner in :gh:`109649`.)
pathlib
-------
* Add :exc:`pathlib.UnsupportedOperation`, which is raised instead of
:exc:`NotImplementedError` when a path operation isn't supported.
(Contributed by Barney Gale in :gh:`89812`.)
* Add support for recursive wildcards in :meth:`pathlib.PurePath.match`.
(Contributed by Barney Gale in :gh:`73435`.)
* Add *follow_symlinks* keyword-only argument to :meth:`pathlib.Path.glob`,
:meth:`~pathlib.Path.rglob`, :meth:`~pathlib.Path.is_file`, and
:meth:`~pathlib.Path.is_dir`.
(Contributed by Barney Gale in :gh:`77609` and :gh:`105793`.)
pdb
---
* Add ability to move between chained exceptions during post mortem debugging in :func:`~pdb.pm` using
the new ``exceptions [exc_number]`` command for Pdb. (Contributed by Matthias
Bussonnier in :gh:`106676`.)
* Expressions/Statements whose prefix is a pdb command are now correctly
identified and executed.
(Contributed by Tian Gao in :gh:`108464`.)
sqlite3
-------
* A :exc:`ResourceWarning` is now emitted if a :class:`sqlite3.Connection`
object is not :meth:`closed <sqlite3.Connection.close>` explicitly.
(Contributed by Erlend E. Aasland in :gh:`105539`.)
tkinter
-------
* Add :mod:`tkinter` widget methods:
:meth:`!tk_busy_hold`, :meth:`!tk_busy_configure`,
:meth:`!tk_busy_cget`, :meth:`!tk_busy_forget`,
:meth:`!tk_busy_current`, and :meth:`!tk_busy_status`.
(Contributed by Miguel, klappnase and Serhiy Storchaka in :gh:`72684`.)
traceback
---------
* Add *show_group* parameter to :func:`traceback.TracebackException.format_exception_only`
to format the nested exceptions of a :exc:`BaseExceptionGroup` instance, recursively.
(Contributed by Irit Katriel in :gh:`105292`.)
typing
------
* Add :func:`typing.get_protocol_members` to return the set of members
defining a :class:`typing.Protocol`. Add :func:`typing.is_protocol` to
check whether a class is a :class:`typing.Protocol`. (Contributed by Jelle Zijlstra in
:gh:`104873`.)
venv
----
* Add support for adding source control management (SCM) ignore files to a
virtual environment's directory. By default, Git is supported. This is
implemented as opt-in via the API which can be extended to support other SCMs
(:class:`venv.EnvBuilder` and :func:`venv.create`), and opt-out via the CLI
(using ``--without-scm-ignore-files``). (Contributed by Brett Cannon in
:gh:`108125`.)
Optimizations
=============
* :func:`textwrap.indent` is now ~30% faster than before for large input.
(Contributed by Inada Naoki in :gh:`107369`.)
Deprecated
==========
* :mod:`array`: :mod:`array`'s ``'u'`` format code, deprecated in docs since Python 3.3,
emits :exc:`DeprecationWarning` since 3.13
and will be removed in Python 3.16.
Use the ``'w'`` format code instead.
(contributed by Hugo van Kemenade in :gh:`80480`)
* :mod:`ctypes`: Deprecate undocumented :func:`!ctypes.SetPointerType`
and :func:`!ctypes.ARRAY` functions.
Replace ``ctypes.ARRAY(item_type, size)`` with ``item_type * size``.
(Contributed by Victor Stinner in :gh:`105733`.)
* :mod:`getopt` and :mod:`optparse` modules: They are now
:term:`soft deprecated`: the :mod:`argparse` should be used for new projects.
Previously, the :mod:`optparse` module was already deprecated, its removal
was not scheduled, and no warnings was emitted: so there is no change in
practice.
(Contributed by Victor Stinner in :gh:`106535`.)
* :mod:`http.server`: :class:`http.server.CGIHTTPRequestHandler` now emits a
:exc:`DeprecationWarning` as it will be removed in 3.15. Process based CGI
http servers have been out of favor for a very long time. This code was
outdated, unmaintained, and rarely used. It has a high potential for both
security and functionality bugs. This includes removal of the ``--cgi``
flag to the ``python -m http.server`` command line in 3.15.
* :mod:`typing`:
* Creating a :class:`typing.NamedTuple` class using keyword arguments to denote
the fields (``NT = NamedTuple("NT", x=int, y=int)``) is deprecated, and will
be disallowed in Python 3.15. Use the class-based syntax or the functional
syntax instead. (Contributed by Alex Waygood in :gh:`105566`.)
* When using the functional syntax to create a :class:`typing.NamedTuple`
class or a :class:`typing.TypedDict` class, failing to pass a value to the
'fields' parameter (``NT = NamedTuple("NT")`` or ``TD = TypedDict("TD")``) is
deprecated. Passing ``None`` to the 'fields' parameter
(``NT = NamedTuple("NT", None)`` or ``TD = TypedDict("TD", None)``) is also
deprecated. Both will be disallowed in Python 3.15. To create a NamedTuple
class with 0 fields, use ``class NT(NamedTuple): pass`` or
``NT = NamedTuple("NT", [])``. To create a TypedDict class with 0 fields, use
``class TD(TypedDict): pass`` or ``TD = TypedDict("TD", {})``.
(Contributed by Alex Waygood in :gh:`105566` and :gh:`105570`.)
* :func:`typing.no_type_check_decorator` is deprecated, and scheduled for
removal in Python 3.15. After eight years in the :mod:`typing` module, it
has yet to be supported by any major type checkers.
(Contributed by Alex Waygood in :gh:`106309`.)
* :data:`typing.AnyStr` is deprecated. In Python 3.16, it will be removed from
``typing.__all__``, and a :exc:`DeprecationWarning` will be emitted when it
is imported or accessed. It will be removed entirely in Python 3.18. Use
the new :ref:`type parameter syntax <type-params>` instead.
(Contributed by Michael The in :gh:`107116`.)
* :mod:`wave`: Deprecate the ``getmark()``, ``setmark()`` and ``getmarkers()``
methods of the :class:`wave.Wave_read` and :class:`wave.Wave_write` classes.
They will be removed in Python 3.15.
(Contributed by Victor Stinner in :gh:`105096`.)
* Passing more than one positional argument to :func:`sqlite3.connect` and the
:class:`sqlite3.Connection` constructor is deprecated. The remaining
parameters will become keyword-only in Python 3.15.
Deprecate passing name, number of arguments, and the callable as keyword
arguments, for the following :class:`sqlite3.Connection` APIs:
* :meth:`~sqlite3.Connection.create_function`
* :meth:`~sqlite3.Connection.create_aggregate`
Deprecate passing the callback callable by keyword for the following
:class:`sqlite3.Connection` APIs:
* :meth:`~sqlite3.Connection.set_authorizer`
* :meth:`~sqlite3.Connection.set_progress_handler`
* :meth:`~sqlite3.Connection.set_trace_callback`
The affected parameters will become positional-only in Python 3.15.
(Contributed by Erlend E. Aasland in :gh:`107948` and :gh:`108278`.)
* The ``dis.HAVE_ARGUMENT`` separator is deprecated. Check membership
in :data:`~dis.hasarg` instead.
(Contributed by Irit Katriel in :gh:`109319`.)
Pending Removal in Python 3.14
------------------------------
* :mod:`argparse`: The *type*, *choices*, and *metavar* parameters
of :class:`!argparse.BooleanOptionalAction` are deprecated
and will be removed in 3.14.
(Contributed by Nikita Sobolev in :gh:`92248`.)
* :mod:`ast`: The following features have been deprecated in documentation
since Python 3.8, now cause a :exc:`DeprecationWarning` to be emitted at
runtime when they are accessed or used, and will be removed in Python 3.14:
* :class:`!ast.Num`
* :class:`!ast.Str`
* :class:`!ast.Bytes`
* :class:`!ast.NameConstant`
* :class:`!ast.Ellipsis`
Use :class:`ast.Constant` instead.
(Contributed by Serhiy Storchaka in :gh:`90953`.)
* :mod:`collections.abc`: Deprecated :class:`~collections.abc.ByteString`.
Prefer :class:`!Sequence` or :class:`~collections.abc.Buffer`.
For use in typing, prefer a union, like ``bytes | bytearray``,
or :class:`collections.abc.Buffer`.
(Contributed by Shantanu Jain in :gh:`91896`.)
* :mod:`email`: Deprecated the *isdst* parameter in :func:`email.utils.localtime`.
(Contributed by Alan Williams in :gh:`72346`.)
* :mod:`importlib`: ``__package__`` and ``__cached__`` will cease to be set or
taken into consideration by the import system (:gh:`97879`).
* :mod:`importlib.abc` deprecated classes:
* :class:`!importlib.abc.ResourceReader`
* :class:`!importlib.abc.Traversable`
* :class:`!importlib.abc.TraversableResources`
Use :mod:`importlib.resources.abc` classes instead:
* :class:`importlib.resources.abc.Traversable`
* :class:`importlib.resources.abc.TraversableResources`
(Contributed by Jason R. Coombs and Hugo van Kemenade in :gh:`93963`.)
* :mod:`itertools` had undocumented, inefficient, historically buggy,
and inconsistent support for copy, deepcopy, and pickle operations.
This will be removed in 3.14 for a significant reduction in code
volume and maintenance burden.
(Contributed by Raymond Hettinger in :gh:`101588`.)
* :mod:`multiprocessing`: The default start method will change to a safer one on
Linux, BSDs, and other non-macOS POSIX platforms where ``'fork'`` is currently
the default (:gh:`84559`). Adding a runtime warning about this was deemed too
disruptive as the majority of code is not expected to care. Use the
:func:`~multiprocessing.get_context` or
:func:`~multiprocessing.set_start_method` APIs to explicitly specify when
your code *requires* ``'fork'``. See :ref:`multiprocessing-start-methods`.
* :mod:`pathlib`: :meth:`~pathlib.PurePath.is_relative_to`,
:meth:`~pathlib.PurePath.relative_to`: passing additional arguments is
deprecated.
* :func:`pkgutil.find_loader` and :func:`pkgutil.get_loader`
now raise :exc:`DeprecationWarning`;
use :func:`importlib.util.find_spec` instead.
(Contributed by Nikita Sobolev in :gh:`97850`.)
* :mod:`pty`:
* ``master_open()``: use :func:`pty.openpty`.
* ``slave_open()``: use :func:`pty.openpty`.
* :func:`shutil.rmtree` *onerror* parameter is deprecated in 3.12,
and will be removed in 3.14: use the *onexc* parameter instead.
* :mod:`sqlite3`:
* :data:`~sqlite3.version` and :data:`~sqlite3.version_info`.
* :meth:`~sqlite3.Cursor.execute` and :meth:`~sqlite3.Cursor.executemany`
if :ref:`named placeholders <sqlite3-placeholders>` are used and
*parameters* is a sequence instead of a :class:`dict`.
* date and datetime adapter, date and timestamp converter:
see the :mod:`sqlite3` documentation for suggested replacement recipes.
* :class:`types.CodeType`: Accessing ``co_lnotab`` was deprecated in :pep:`626`
since 3.10 and was planned to be removed in 3.12,
but it only got a proper :exc:`DeprecationWarning` in 3.12.
May be removed in 3.14.
(Contributed by Nikita Sobolev in :gh:`101866`.)
* :mod:`typing`: :class:`~typing.ByteString`, deprecated since Python 3.9,
now causes a :exc:`DeprecationWarning` to be emitted when it is used.
* :class:`!urllib.parse.Quoter` is deprecated: it was not intended to be a
public API.
(Contributed by Gregory P. Smith in :gh:`88168`.)
* :mod:`xml.etree.ElementTree`: Testing the truth value of an
:class:`~xml.etree.ElementTree.Element` is deprecated and will raise an
exception in Python 3.14.
Pending Removal in Python 3.15
------------------------------
* :class:`http.server.CGIHTTPRequestHandler` will be removed along with its
related ``--cgi`` flag to ``python -m http.server``. It was obsolete and
rarely used. No direct replacement exists. *Anything* is better than CGI
to interface a web server with a request handler.
* :class:`typing.NamedTuple`:
* The undocumented keyword argument syntax for creating NamedTuple classes
(``NT = NamedTuple("NT", x=int)``) is deprecated, and will be disallowed in
3.15. Use the class-based syntax or the functional syntax instead.
* When using the functional syntax to create a NamedTuple class, failing to
pass a value to the 'fields' parameter (``NT = NamedTuple("NT")``) is
deprecated. Passing ``None`` to the 'fields' parameter
(``NT = NamedTuple("NT", None)``) is also deprecated. Both will be
disallowed in Python 3.15. To create a NamedTuple class with 0 fields, use
``class NT(NamedTuple): pass`` or ``NT = NamedTuple("NT", [])``.
* :class:`typing.TypedDict`: When using the functional syntax to create a
TypedDict class, failing to pass a value to the 'fields' parameter (``TD =
TypedDict("TD")``) is deprecated. Passing ``None`` to the 'fields' parameter
(``TD = TypedDict("TD", None)``) is also deprecated. Both will be disallowed
in Python 3.15. To create a TypedDict class with 0 fields, use ``class
TD(TypedDict): pass`` or ``TD = TypedDict("TD", {})``.
* :mod:`wave`: Deprecate the ``getmark()``, ``setmark()`` and ``getmarkers()``
methods of the :class:`wave.Wave_read` and :class:`wave.Wave_write` classes.
They will be removed in Python 3.15.
(Contributed by Victor Stinner in :gh:`105096`.)
* Passing any arguments to :func:`threading.RLock` is now deprecated.
C version allows any numbers of args and kwargs,
but they are just ignored. Python version does not allow any arguments.
All arguments will be removed from :func:`threading.RLock` in Python 3.15.
(Contributed by Nikita Sobolev in :gh:`102029`.)
Pending Removal in Python 3.16
------------------------------
* :class:`array.array` ``'u'`` type (:c:type:`wchar_t`):
use the ``'w'`` type instead (``Py_UCS4``).
Pending Removal in Future Versions
----------------------------------
The following APIs were deprecated in earlier Python versions and will be removed,
although there is currently no date scheduled for their removal.
* :mod:`argparse`: Nesting argument groups and nesting mutually exclusive
groups are deprecated.
* :mod:`builtins`:
* ``~bool``, bitwise inversion on bool.
* ``bool(NotImplemented)``.
* Generators: ``throw(type, exc, tb)`` and ``athrow(type, exc, tb)``
signature is deprecated: use ``throw(exc)`` and ``athrow(exc)`` instead,
the single argument signature.
* Currently Python accepts numeric literals immediately followed by keywords,
for example ``0in x``, ``1or x``, ``0if 1else 2``. It allows confusing and
ambiguous expressions like ``[0x1for x in y]`` (which can be interpreted as
``[0x1 for x in y]`` or ``[0x1f or x in y]``). A syntax warning is raised
if the numeric literal is immediately followed by one of keywords
:keyword:`and`, :keyword:`else`, :keyword:`for`, :keyword:`if`,
:keyword:`in`, :keyword:`is` and :keyword:`or`. In a future release it
will be changed to a syntax error. (:gh:`87999`)
* Support for ``__index__()`` and ``__int__()`` method returning non-int type:
these methods will be required to return an instance of a strict subclass of
:class:`int`.
* Support for ``__float__()`` method returning a strict subclass of
:class:`float`: these methods will be required to return an instance of
:class:`float`.
* Support for ``__complex__()`` method returning a strict subclass of
:class:`complex`: these methods will be required to return an instance of
:class:`complex`.
* Delegation of ``int()`` to ``__trunc__()`` method.
* :mod:`calendar`: ``calendar.January`` and ``calendar.February`` constants are
deprecated and replaced by :data:`calendar.JANUARY` and
:data:`calendar.FEBRUARY`.
(Contributed by Prince Roshan in :gh:`103636`.)
* :mod:`datetime`:
* :meth:`~datetime.datetime.utcnow`:
use ``datetime.datetime.now(tz=datetime.UTC)``.
* :meth:`~datetime.datetime.utcfromtimestamp`:
use ``datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC)``.
* :mod:`gettext`: Plural value must be an integer.
* :mod:`importlib`:
* ``load_module()`` method: use ``exec_module()`` instead.
* :func:`~importlib.util.cache_from_source` *debug_override* parameter is
deprecated: use the *optimization* parameter instead.
* :mod:`importlib.metadata`:
* ``EntryPoints`` tuple interface.
* Implicit ``None`` on return values.
* :mod:`importlib.resources`: First parameter to files is renamed to 'anchor'.
* :mod:`importlib.resources` deprecated methods:
* ``contents()``
* ``is_resource()``
* ``open_binary()``
* ``open_text()``
* ``path()``
* ``read_binary()``
* ``read_text()``
Use ``files()`` instead. Refer to `importlib-resources: Migrating from Legacy
<https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy>`_
for migration advice.
* :func:`locale.getdefaultlocale`: use :func:`locale.setlocale()`,
:func:`locale.getencoding()` and :func:`locale.getlocale()` instead
(:gh:`90817`)
* :mod:`mailbox`: Use of StringIO input and text mode is deprecated, use
BytesIO and binary mode instead.
* :mod:`os`: Calling :func:`os.register_at_fork` in multi-threaded process.
* :class:`!pydoc.ErrorDuringImport`: A tuple value for *exc_info* parameter is
deprecated, use an exception instance.
* :mod:`re`: More strict rules are now applied for numerical group references
and group names in regular expressions. Only sequence of ASCII digits is now
accepted as a numerical reference. The group name in bytes patterns and
replacement strings can now only contain ASCII letters and digits and
underscore.
(Contributed by Serhiy Storchaka in :gh:`91760`.)
* :mod:`ssl` options and protocols:
* :class:`ssl.SSLContext` without protocol argument is deprecated.
* :class:`ssl.SSLContext`: :meth:`~ssl.SSLContext.set_npn_protocols` and
:meth:`!~ssl.SSLContext.selected_npn_protocol` are deprecated: use ALPN
instead.
* ``ssl.OP_NO_SSL*`` options
* ``ssl.OP_NO_TLS*`` options
* ``ssl.PROTOCOL_SSLv3``
* ``ssl.PROTOCOL_TLS``
* ``ssl.PROTOCOL_TLSv1``
* ``ssl.PROTOCOL_TLSv1_1``
* ``ssl.PROTOCOL_TLSv1_2``
* ``ssl.TLSVersion.SSLv3``
* ``ssl.TLSVersion.TLSv1``
* ``ssl.TLSVersion.TLSv1_1``
* :mod:`!sre_compile`, :mod:`!sre_constants` and :mod:`!sre_parse` modules.
* ``types.CodeType.co_lnotab``: use the ``co_lines`` attribute instead.
* :class:`typing.Text` (:gh:`92332`).
* :func:`sysconfig.is_python_build` *check_home* parameter is deprecated and
ignored.
* :mod:`threading` methods:
* :meth:`!threading.Condition.notifyAll`: use :meth:`~threading.Condition.notify_all`.
* :meth:`!threading.Event.isSet`: use :meth:`~threading.Event.is_set`.
* :meth:`!threading.Thread.isDaemon`, :meth:`threading.Thread.setDaemon`:
use :attr:`threading.Thread.daemon` attribute.
* :meth:`!threading.Thread.getName`, :meth:`threading.Thread.setName`:
use :attr:`threading.Thread.name` attribute.
* :meth:`!threading.currentThread`: use :meth:`threading.current_thread`.
* :meth:`!threading.activeCount`: use :meth:`threading.active_count`.
* :class:`unittest.IsolatedAsyncioTestCase`: it is deprecated to return a value
that is not None from a test case.
* :mod:`urllib.request`: :class:`~urllib.request.URLopener` and
:class:`~urllib.request.FancyURLopener` style of invoking requests is
deprecated. Use newer :func:`~urllib.request.urlopen` functions and methods.
* :func:`!urllib.parse.to_bytes`.
* :mod:`urllib.parse` deprecated functions: :func:`~urllib.parse.urlparse` instead
* ``splitattr()``
* ``splithost()``
* ``splitnport()``
* ``splitpasswd()``
* ``splitport()``
* ``splitquery()``
* ``splittag()``
* ``splittype()``
* ``splituser()``
* ``splitvalue()``
* :mod:`wsgiref`: ``SimpleHandler.stdout.write()`` should not do partial
writes.
* :meth:`zipimport.zipimporter.load_module` is deprecated:
use :meth:`~zipimport.zipimporter.exec_module` instead.
Removed
=======
* :pep:`594`: Remove the :mod:`!telnetlib` module, deprecated in Python 3.11:
use the projects `telnetlib3 <https://pypi.org/project/telnetlib3/>`_ or
`Exscript <https://pypi.org/project/Exscript/>`_ instead.
(Contributed by Victor Stinner in :gh:`104773`.)
* Remove the ``2to3`` program and the :mod:`!lib2to3` module,
deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104780`.)
* Namespaces ``typing.io`` and ``typing.re``, deprecated in Python 3.8,
are now removed. The items in those namespaces can be imported directly
from :mod:`typing`. (Contributed by Sebastian Rittau in :gh:`92871`.)
* Remove the untested and undocumented :mod:`webbrowser` :class:`!MacOSX` class,
deprecated in Python 3.11.
Use the :class:`!MacOSXOSAScript` class (introduced in Python 3.2) instead.
(Contributed by Hugo van Kemenade in :gh:`104804`.)
* Remove support for using :class:`pathlib.Path` objects as context managers.
This functionality was deprecated and made a no-op in Python 3.9.
* Remove the undocumented :class:`!configparser.LegacyInterpolation` class,
deprecated in the docstring since Python 3.2,
and with a deprecation warning since Python 3.11.
(Contributed by Hugo van Kemenade in :gh:`104886`.)
* Remove the :meth:`!turtle.RawTurtle.settiltangle` method,
deprecated in docs since Python 3.1
and with a deprecation warning since Python 3.11.
(Contributed by Hugo van Kemenade in :gh:`104876`.)
* Removed the following :mod:`unittest` functions, deprecated in Python 3.11:
* :func:`!unittest.findTestCases`
* :func:`!unittest.makeSuite`
* :func:`!unittest.getTestCaseNames`
Use :class:`~unittest.TestLoader` methods instead:
* :meth:`unittest.TestLoader.loadTestsFromModule`
* :meth:`unittest.TestLoader.loadTestsFromTestCase`
* :meth:`unittest.TestLoader.getTestCaseNames`
(Contributed by Hugo van Kemenade in :gh:`104835`.)
* :pep:`594`: Remove the :mod:`!cgi` and :mod:`!cgitb` modules,
deprecated in Python 3.11.
* ``cgi.FieldStorage`` can typically be replaced with
:func:`urllib.parse.parse_qsl` for ``GET`` and ``HEAD`` requests, and the
:mod:`email.message` module or `multipart
<https://pypi.org/project/multipart/>`__ PyPI project for ``POST`` and
``PUT``.
* ``cgi.parse()`` can be replaced by calling :func:`urllib.parse.parse_qs`
directly on the desired query string, except for ``multipart/form-data``
input, which can be handled as described for ``cgi.parse_multipart()``.
* ``cgi.parse_multipart()`` can be replaced with the functionality in the
:mod:`email` package (e.g. :class:`email.message.EmailMessage` and
:class:`email.message.Message`) which implements the same MIME RFCs, or
with the `multipart <https://pypi.org/project/multipart/>`__ PyPI project.
* ``cgi.parse_header()`` can be replaced with the functionality in the
:mod:`email` package, which implements the same MIME RFCs. For example,
with :class:`email.message.EmailMessage`::
from email.message import EmailMessage
msg = EmailMessage()
msg['content-type'] = 'application/json; charset="utf8"'
main, params = msg.get_content_type(), msg['content-type'].params
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!sndhdr` module, deprecated in Python 3.11: use
the projects `filetype <https://pypi.org/project/filetype/>`_, `puremagic
<https://pypi.org/project/puremagic/>`_, or `python-magic
<https://pypi.org/project/python-magic/>`_ instead.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!pipes` module, deprecated in Python 3.11:
use the :mod:`subprocess` module instead.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!ossaudiodev` module, deprecated in Python 3.11:
use the `pygame project <https://www.pygame.org/>`_ for audio playback.
(Contributed by Victor Stinner in :gh:`104780`.)
* :pep:`594`: Remove the :mod:`!sunau` module, deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!mailcap` module, deprecated in Python 3.11.
The :mod:`mimetypes` module provides an alternative.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!spwd` module, deprecated in Python 3.11:
the `python-pam project <https://pypi.org/project/python-pam/>`_ can be used
instead.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!nntplib` module, deprecated in Python 3.11:
the `PyPI nntplib project <https://pypi.org/project/nntplib/>`_ can be used
instead.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!nis` module, deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!xdrlib` module, deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!msilib` module, deprecated in Python 3.11.
(Contributed by Zachary Ware in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!crypt` module and its private :mod:`!_crypt`
extension, deprecated in Python 3.11.
The :mod:`hashlib` module is a potential replacement for certain use cases.
Otherwise, the following PyPI projects can be used:
* `bcrypt <https://pypi.org/project/bcrypt/>`_:
Modern password hashing for your software and your servers.
* `passlib <https://pypi.org/project/passlib/>`_:
Comprehensive password hashing framework supporting over 30 schemes.
* `argon2-cffi <https://pypi.org/project/argon2-cffi/>`_:
The secure Argon2 password hashing algorithm.
* `legacycrypt <https://pypi.org/project/legacycrypt/>`_:
Wrapper to the POSIX crypt library call and associated functionality.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!uu` module, deprecated in Python 3.11:
the :mod:`base64` module is a modern alternative.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!aifc` module, deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!audioop` module, deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104773`.)
* :pep:`594`: Remove the :mod:`!chunk` module, deprecated in Python 3.11.
(Contributed by Victor Stinner in :gh:`104773`.)
* Remove support for the keyword-argument method of creating
:class:`typing.TypedDict` types, deprecated in Python 3.11.
(Contributed by Tomas Roun in :gh:`104786`.)
* :pep:`594`: Remove the :mod:`!imghdr` module, deprecated in Python 3.11:
use the projects
`filetype <https://pypi.org/project/filetype/>`_,
`puremagic <https://pypi.org/project/puremagic/>`_,
or `python-magic <https://pypi.org/project/python-magic/>`_ instead.
(Contributed by Victor Stinner in :gh:`104773`.)
* Remove the untested and undocumented :meth:`!unittest.TestProgram.usageExit`
method, deprecated in Python 3.11.
(Contributed by Hugo van Kemenade in :gh:`104992`.)
* Remove the :mod:`!tkinter.tix` module, deprecated in Python 3.6. The
third-party Tix library which the module wrapped is unmaintained.
(Contributed by Zachary Ware in :gh:`75552`.)
* Remove the old trashcan macros ``Py_TRASHCAN_SAFE_BEGIN`` and
``Py_TRASHCAN_SAFE_END``. They should be replaced by the new macros
``Py_TRASHCAN_BEGIN`` and ``Py_TRASHCAN_END``. The new macros were
added in Python 3.8 and the old macros were deprecated in Python 3.11.
(Contributed by Irit Katriel in :gh:`105111`.)
* Remove ``locale.resetlocale()`` function deprecated in Python 3.11:
use ``locale.setlocale(locale.LC_ALL, "")`` instead.
(Contributed by Victor Stinner in :gh:`104783`.)
* :mod:`logging`: Remove undocumented and untested ``Logger.warn()`` and
``LoggerAdapter.warn()`` methods and ``logging.warn()`` function. Deprecated
since Python 3.3, they were aliases to the :meth:`logging.Logger.warning`
method, :meth:`!logging.LoggerAdapter.warning` method and
:func:`logging.warning` function.
(Contributed by Victor Stinner in :gh:`105376`.)
* Remove *cafile*, *capath* and *cadefault* parameters of the
:func:`urllib.request.urlopen` function, deprecated in Python 3.6: use the
*context* parameter instead. Please use
:meth:`ssl.SSLContext.load_cert_chain` instead, or let
:func:`ssl.create_default_context` select the system's trusted CA
certificates for you.
(Contributed by Victor Stinner in :gh:`105382`.)
* Remove deprecated ``webbrowser.MacOSXOSAScript._name`` attribute.
Use :attr:`webbrowser.MacOSXOSAScript.name <webbrowser.controller.name>`
attribute instead.
(Contributed by Nikita Sobolev in :gh:`105546`.)
* Remove undocumented, never working, and deprecated ``re.template`` function
and ``re.TEMPLATE`` flag (and ``re.T`` alias).
(Contributed by Serhiy Storchaka and Nikita Sobolev in :gh:`105687`.)
Porting to Python 3.13
======================
This section lists previously described changes and other bugfixes
that may require changes to your code.
* The old trashcan macros ``Py_TRASHCAN_SAFE_BEGIN`` and ``Py_TRASHCAN_SAFE_END``
were removed. They should be replaced by the new macros ``Py_TRASHCAN_BEGIN``
and ``Py_TRASHCAN_END``.
A tp_dealloc function that has the old macros, such as::
static void
mytype_dealloc(mytype *p)
{
PyObject_GC_UnTrack(p);
Py_TRASHCAN_SAFE_BEGIN(p);
...
Py_TRASHCAN_SAFE_END
}
should migrate to the new macros as follows::
static void
mytype_dealloc(mytype *p)
{
PyObject_GC_UnTrack(p);
Py_TRASHCAN_BEGIN(p, mytype_dealloc)
...
Py_TRASHCAN_END
}
Note that ``Py_TRASHCAN_BEGIN`` has a second argument which
should be the deallocation function it is in.
Build Changes
=============
* Autoconf 2.71 and aclocal 1.16.4 is now required to regenerate
the :file:`configure` script.
(Contributed by Christian Heimes in :gh:`89886`.)
* SQLite 3.15.2 or newer is required to build the :mod:`sqlite3` extension module.
(Contributed by Erlend Aasland in :gh:`105875`.)
* Python built with :file:`configure` :option:`--with-trace-refs` (tracing
references) is now ABI compatible with Python release build and
:ref:`debug build <debug-build>`.
(Contributed by Victor Stinner in :gh:`108634`.)
* Building CPython now requires a compiler with support for the C11 atomic
library, GCC built-in atomic functions, or MSVC interlocked intrinsics.
C API Changes
=============
New Features
------------
* You no longer have to define the ``PY_SSIZE_T_CLEAN`` macro before including
:file:`Python.h` when using ``#`` formats in
:ref:`format codes <arg-parsing-string-and-buffers>`.
APIs accepting the format codes always use ``Py_ssize_t`` for ``#`` formats.
(Contributed by Inada Naoki in :gh:`104922`.)
* Add :c:func:`PyImport_AddModuleRef`: similar to
:c:func:`PyImport_AddModule`, but return a :term:`strong reference` instead
of a :term:`borrowed reference`.
(Contributed by Victor Stinner in :gh:`105922`.)
* Add :c:func:`PyWeakref_GetRef` function: similar to
:c:func:`PyWeakref_GetObject` but returns a :term:`strong reference`, or
``NULL`` if the referent is no longer live.
(Contributed by Victor Stinner in :gh:`105927`.)
* Add :c:func:`PyObject_GetOptionalAttr` and
:c:func:`PyObject_GetOptionalAttrString`, variants of
:c:func:`PyObject_GetAttr` and :c:func:`PyObject_GetAttrString` which
don't raise :exc:`AttributeError` if the attribute is not found.
These variants are more convenient and faster if the missing attribute
should not be treated as a failure.
(Contributed by Serhiy Storchaka in :gh:`106521`.)
* Add :c:func:`PyMapping_GetOptionalItem` and
:c:func:`PyMapping_GetOptionalItemString`: variants of
:c:func:`PyObject_GetItem` and :c:func:`PyMapping_GetItemString` which don't
raise :exc:`KeyError` if the key is not found.
These variants are more convenient and faster if the missing key should not
be treated as a failure.
(Contributed by Serhiy Storchaka in :gh:`106307`.)
* Add fixed variants of functions which silently ignore errors:
- :c:func:`PyObject_HasAttrWithError` replaces :c:func:`PyObject_HasAttr`.
- :c:func:`PyObject_HasAttrStringWithError` replaces :c:func:`PyObject_HasAttrString`.
- :c:func:`PyMapping_HasKeyWithError` replaces :c:func:`PyMapping_HasKey`.
- :c:func:`PyMapping_HasKeyStringWithError` replaces :c:func:`PyMapping_HasKeyString`.
New functions return not only ``1`` for true and ``0`` for false, but also
``-1`` for error.
(Contributed by Serhiy Storchaka in :gh:`108511`.)
* If Python is built in :ref:`debug mode <debug-build>` or :option:`with
assertions <--with-assertions>`, :c:func:`PyTuple_SET_ITEM` and
:c:func:`PyList_SET_ITEM` now check the index argument with an assertion.
If the assertion fails, make sure that the size is set before.
(Contributed by Victor Stinner in :gh:`106168`.)
* Add :c:func:`PyModule_Add` function: similar to
:c:func:`PyModule_AddObjectRef` and :c:func:`PyModule_AddObject` but
always steals a reference to the value.
(Contributed by Serhiy Storchaka in :gh:`86493`.)
* Added :c:func:`PyDict_GetItemRef` and :c:func:`PyDict_GetItemStringRef`
functions: similar to :c:func:`PyDict_GetItemWithError` but returning a
:term:`strong reference` instead of a :term:`borrowed reference`. Moreover,
these functions return -1 on error and so checking ``PyErr_Occurred()`` is
not needed.
(Contributed by Victor Stinner in :gh:`106004`.)
* Added :c:func:`PyDict_ContainsString` function: same as
:c:func:`PyDict_Contains`, but *key* is specified as a :c:expr:`const char*`
UTF-8 encoded bytes string, rather than a :c:expr:`PyObject*`.
(Contributed by Victor Stinner in :gh:`108314`.)
* Add :c:func:`Py_IsFinalizing` function: check if the main Python interpreter is
:term:`shutting down <interpreter shutdown>`.
(Contributed by Victor Stinner in :gh:`108014`.)
* Add :c:func:`PyLong_AsInt` function: similar to :c:func:`PyLong_AsLong`, but
store the result in a C :c:expr:`int` instead of a C :c:expr:`long`.
Previously, it was known as the private function :c:func:`!_PyLong_AsInt`
(with an underscore prefix).
(Contributed by Victor Stinner in :gh:`108014`.)
* Python built with :file:`configure` :option:`--with-trace-refs` (tracing
references) now supports the :ref:`Limited API <limited-c-api>`.
(Contributed by Victor Stinner in :gh:`108634`.)
Porting to Python 3.13
----------------------
* ``Python.h`` no longer includes the ``<ieeefp.h>`` standard header. It was
included for the ``finite()`` function which is now provided by the
``<math.h>`` header. It should now be included explicitly if needed. Remove
also the ``HAVE_IEEEFP_H`` macro.
(Contributed by Victor Stinner in :gh:`108765`.)
* ``Python.h`` no longer includes the ``<unistd.h>`` standard header file. If
needed, it should now be included explicitly. For example, it provides the
functions: ``read()``, ``write()``, ``close()``, ``isatty()``, ``lseek()``,
``getpid()``, ``getcwd()``, ``sysconf()`` and ``getpagesize()``.
As a consequence, ``_POSIX_SEMAPHORES`` and ``_POSIX_THREADS`` macros are no
longer defined by ``Python.h``. The ``HAVE_UNISTD_H`` and ``HAVE_PTHREAD_H``
macros defined by ``Python.h`` can be used to decide if ``<unistd.h>`` and
``<pthread.h>`` header files can be included.
(Contributed by Victor Stinner in :gh:`108765`.)
* ``Python.h`` no longer includes these standard header files: ``<time.h>``,
``<sys/select.h>`` and ``<sys/time.h>``. If needed, they should now be
included explicitly. For example, ``<time.h>`` provides the ``clock()`` and
``gmtime()`` functions, ``<sys/select.h>`` provides the ``select()``
function, and ``<sys/time.h>`` provides the ``futimes()``, ``gettimeofday()``
and ``setitimer()`` functions.
(Contributed by Victor Stinner in :gh:`108765`.)
* ``Python.h`` no longer includes the ``<ctype.h>`` standard header file. If
needed, it should now be included explicitly. For example, it provides
``isalpha()`` and ``tolower()`` functions which are locale dependent. Python
provides locale independent functions, like :c:func:`!Py_ISALPHA` and
:c:func:`!Py_TOLOWER`.
(Contributed by Victor Stinner in :gh:`108765`.)
Deprecated
----------
* Passing optional arguments *maxsplit*, *count* and *flags* in module-level
functions :func:`re.split`, :func:`re.sub` and :func:`re.subn` as positional
arguments is now deprecated.
In future Python versions these parameters will be
:ref:`keyword-only <keyword-only_parameter>`.
(Contributed by Serhiy Storchaka in :gh:`56166`.)
* Deprecate the old ``Py_UNICODE`` and ``PY_UNICODE_TYPE`` types: use directly
the :c:type:`wchar_t` type instead. Since Python 3.3, ``Py_UNICODE`` and
``PY_UNICODE_TYPE`` are just aliases to :c:type:`wchar_t`.
(Contributed by Victor Stinner in :gh:`105156`.)
* Deprecate old Python initialization functions:
* :c:func:`PySys_ResetWarnOptions`:
clear :data:`sys.warnoptions` and :data:`!warnings.filters` instead.
* :c:func:`Py_GetExecPrefix`: get :data:`sys.exec_prefix` instead.
* :c:func:`Py_GetPath`: get :data:`sys.path` instead.
* :c:func:`Py_GetPrefix`: get :data:`sys.prefix` instead.
* :c:func:`Py_GetProgramFullPath`: get :data:`sys.executable` instead.
* :c:func:`Py_GetProgramName`: get :data:`sys.executable` instead.
* :c:func:`Py_GetPythonHome`: get :c:member:`PyConfig.home` or
:envvar:`PYTHONHOME` environment variable instead.
Functions scheduled for removal in Python 3.15.
(Contributed by Victor Stinner in :gh:`105145`.)
* Deprecate the :c:func:`PyImport_ImportModuleNoBlock` function which is just
an alias to :c:func:`PyImport_ImportModule` since Python 3.3.
Scheduled for removal in Python 3.15.
(Contributed by Victor Stinner in :gh:`105396`.)
* Deprecate the :c:func:`PyWeakref_GetObject` and
:c:func:`PyWeakref_GET_OBJECT` functions, which return a :term:`borrowed
reference`: use the new :c:func:`PyWeakref_GetRef` function instead, it
returns a :term:`strong reference`. The `pythoncapi-compat project
<https://github.com/python/pythoncapi-compat/>`__ can be used to get
:c:func:`PyWeakref_GetRef` on Python 3.12 and older.
(Contributed by Victor Stinner in :gh:`105927`.)
Removed
-------
* Remove many APIs (functions, macros, variables) with names prefixed by
``_Py`` or ``_PY`` (considered as private API). If your project is affected
by one of these removals and you consider that the removed API should remain
available, please open a new issue to request a public C API and
add ``cc @vstinner`` to the issue to notify Victor Stinner.
(Contributed by Victor Stinner in :gh:`106320`.)
* Remove functions deprecated in Python 3.9.
* ``PyEval_CallObject()``, ``PyEval_CallObjectWithKeywords()``: use
:c:func:`PyObject_CallNoArgs` or :c:func:`PyObject_Call` instead.
Warning: :c:func:`PyObject_Call` positional arguments must be a
:class:`tuple` and must not be *NULL*, keyword arguments must be a
:class:`dict` or *NULL*, whereas removed functions checked arguments type
and accepted *NULL* positional and keyword arguments.
To replace ``PyEval_CallObjectWithKeywords(func, NULL, kwargs)`` with
:c:func:`PyObject_Call`, pass an empty tuple as positional arguments using
:c:func:`PyTuple_New(0) <PyTuple_New>`.
* ``PyEval_CallFunction()``: use :c:func:`PyObject_CallFunction` instead.
* ``PyEval_CallMethod()``: use :c:func:`PyObject_CallMethod` instead.
* ``PyCFunction_Call()``: use :c:func:`PyObject_Call` instead.
(Contributed by Victor Stinner in :gh:`105107`.)
* Remove old buffer protocols deprecated in Python 3.0. Use :ref:`bufferobjects` instead.
* :c:func:`!PyObject_CheckReadBuffer`: Use :c:func:`PyObject_CheckBuffer` to
test if the object supports the buffer protocol.
Note that :c:func:`PyObject_CheckBuffer` doesn't guarantee that
:c:func:`PyObject_GetBuffer` will succeed.
To test if the object is actually readable, see the next example
of :c:func:`PyObject_GetBuffer`.
* :c:func:`!PyObject_AsCharBuffer`, :c:func:`!PyObject_AsReadBuffer`:
:c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release` instead:
.. code-block:: c
Py_buffer view;
if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) < 0) {
return NULL;
}
// Use `view.buf` and `view.len` to read from the buffer.
// You may need to cast buf as `(const char*)view.buf`.
PyBuffer_Release(&view);
* :c:func:`!PyObject_AsWriteBuffer`: Use
:c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release` instead:
.. code-block:: c
Py_buffer view;
if (PyObject_GetBuffer(obj, &view, PyBUF_WRITABLE) < 0) {
return NULL;
}
// Use `view.buf` and `view.len` to write to the buffer.
PyBuffer_Release(&view);
(Contributed by Inada Naoki in :gh:`85275`.)
* Remove the following old functions to configure the Python initialization,
deprecated in Python 3.11:
* ``PySys_AddWarnOptionUnicode()``: use :c:member:`PyConfig.warnoptions` instead.
* ``PySys_AddWarnOption()``: use :c:member:`PyConfig.warnoptions` instead.
* ``PySys_AddXOption()``: use :c:member:`PyConfig.xoptions` instead.
* ``PySys_HasWarnOptions()``: use :c:member:`PyConfig.xoptions` instead.
* ``PySys_SetArgvEx()``: set :c:member:`PyConfig.argv` instead.
* ``PySys_SetArgv()``: set :c:member:`PyConfig.argv` instead.
* ``PySys_SetPath()``: set :c:member:`PyConfig.module_search_paths` instead.
* ``Py_SetPath()``: set :c:member:`PyConfig.module_search_paths` instead.
* ``Py_SetProgramName()``: set :c:member:`PyConfig.program_name` instead.
* ``Py_SetPythonHome()``: set :c:member:`PyConfig.home` instead.
* ``Py_SetStandardStreamEncoding()``: set :c:member:`PyConfig.stdio_encoding`
instead, and set also maybe :c:member:`PyConfig.legacy_windows_stdio` (on
Windows).
* ``_Py_SetProgramFullPath()``: set :c:member:`PyConfig.executable` instead.
Use the new :c:type:`PyConfig` API of the :ref:`Python Initialization
Configuration <init-config>` instead (:pep:`587`), added to Python 3.8.
(Contributed by Victor Stinner in :gh:`105145`.)
* Remove ``PyEval_InitThreads()`` and ``PyEval_ThreadsInitialized()``
functions, deprecated in Python 3.9. Since Python 3.7, ``Py_Initialize()``
always creates the GIL: calling ``PyEval_InitThreads()`` did nothing and
``PyEval_ThreadsInitialized()`` always returned non-zero.
(Contributed by Victor Stinner in :gh:`105182`.)
* Remove ``PyEval_AcquireLock()`` and ``PyEval_ReleaseLock()`` functions,
deprecated in Python 3.2. They didn't update the current thread state.
They can be replaced with:
* :c:func:`PyEval_SaveThread` and :c:func:`PyEval_RestoreThread`;
* low-level :c:func:`PyEval_AcquireThread` and :c:func:`PyEval_RestoreThread`;
* or :c:func:`PyGILState_Ensure` and :c:func:`PyGILState_Release`.
(Contributed by Victor Stinner in :gh:`105182`.)
* Remove the old aliases to functions calling functions which were kept for
backward compatibility with Python 3.8 provisional API:
* ``_PyObject_CallMethodNoArgs()``: use ``PyObject_CallMethodNoArgs()``
* ``_PyObject_CallMethodOneArg()``: use ``PyObject_CallMethodOneArg()``
* ``_PyObject_CallOneArg()``: use ``PyObject_CallOneArg()``
* ``_PyObject_FastCallDict()``: use ``PyObject_VectorcallDict()``
* ``_PyObject_Vectorcall()``: use ``PyObject_Vectorcall()``
* ``_PyObject_VectorcallMethod()``: use ``PyObject_VectorcallMethod()``
* ``_PyVectorcall_Function()``: use ``PyVectorcall_Function()``
Just remove the underscore prefix to update your code.
(Contributed by Victor Stinner in :gh:`106084`.)
* Remove private ``_PyObject_FastCall()`` function:
use ``PyObject_Vectorcall()`` which is available since Python 3.8
(:pep:`590`).
(Contributed by Victor Stinner in :gh:`106023`.)
* Remove ``cpython/pytime.h`` header file: it only contained private functions.
(Contributed by Victor Stinner in :gh:`106316`.)
* Remove ``_PyInterpreterState_Get()`` alias to
:c:func:`PyInterpreterState_Get()` which was kept for backward compatibility
with Python 3.8. The `pythoncapi-compat project
<https://github.com/python/pythoncapi-compat/>`__ can be used to get
:c:func:`PyInterpreterState_Get()` on Python 3.8 and older.
(Contributed by Victor Stinner in :gh:`106320`.)
* The :c:func:`PyModule_AddObject` function is now :term:`soft deprecated`:
:c:func:`PyModule_Add` or :c:func:`PyModule_AddObjectRef` functions should
be used instead.
(Contributed by Serhiy Storchaka in :gh:`86493`.)
Pending Removal in Python 3.14
------------------------------
* Creating immutable types (:c:macro:`Py_TPFLAGS_IMMUTABLETYPE`) with mutable
bases using the C API.
* Global configuration variables:
* :c:var:`Py_DebugFlag`: use :c:member:`PyConfig.parser_debug`
* :c:var:`Py_VerboseFlag`: use :c:member:`PyConfig.verbose`
* :c:var:`Py_QuietFlag`: use :c:member:`PyConfig.quiet`
* :c:var:`Py_InteractiveFlag`: use :c:member:`PyConfig.interactive`
* :c:var:`Py_InspectFlag`: use :c:member:`PyConfig.inspect`
* :c:var:`Py_OptimizeFlag`: use :c:member:`PyConfig.optimization_level`
* :c:var:`Py_NoSiteFlag`: use :c:member:`PyConfig.site_import`
* :c:var:`Py_BytesWarningFlag`: use :c:member:`PyConfig.bytes_warning`
* :c:var:`Py_FrozenFlag`: use :c:member:`PyConfig.pathconfig_warnings`
* :c:var:`Py_IgnoreEnvironmentFlag`: use :c:member:`PyConfig.use_environment`
* :c:var:`Py_DontWriteBytecodeFlag`: use :c:member:`PyConfig.write_bytecode`
* :c:var:`Py_NoUserSiteDirectory`: use :c:member:`PyConfig.user_site_directory`
* :c:var:`Py_UnbufferedStdioFlag`: use :c:member:`PyConfig.buffered_stdio`
* :c:var:`Py_HashRandomizationFlag`: use :c:member:`PyConfig.use_hash_seed`
and :c:member:`PyConfig.hash_seed`
* :c:var:`Py_IsolatedFlag`: use :c:member:`PyConfig.isolated`
* :c:var:`Py_LegacyWindowsFSEncodingFlag`: use :c:member:`PyPreConfig.legacy_windows_fs_encoding`
* :c:var:`Py_LegacyWindowsStdioFlag`: use :c:member:`PyConfig.legacy_windows_stdio`
* :c:var:`!Py_FileSystemDefaultEncoding`: use :c:member:`PyConfig.filesystem_encoding`
* :c:var:`!Py_HasFileSystemDefaultEncoding`: use :c:member:`PyConfig.filesystem_encoding`
* :c:var:`!Py_FileSystemDefaultEncodeErrors`: use :c:member:`PyConfig.filesystem_errors`
* :c:var:`!Py_UTF8Mode`: use :c:member:`PyPreConfig.utf8_mode` (see :c:func:`Py_PreInitialize`)
The :c:func:`Py_InitializeFromConfig` API should be used with
:c:type:`PyConfig` instead.
Pending Removal in Python 3.15
------------------------------
* :c:func:`PyImport_ImportModuleNoBlock`: use :c:func:`PyImport_ImportModule`.
* :c:func:`PyWeakref_GET_OBJECT`: use :c:func:`PyWeakref_GetRef` instead.
* :c:func:`PyWeakref_GetObject`: use :c:func:`PyWeakref_GetRef` instead.
* :c:type:`!Py_UNICODE_WIDE` type: use :c:type:`wchar_t` instead.
* :c:type:`Py_UNICODE` type: use :c:type:`wchar_t` instead.
* Python initialization functions:
* :c:func:`PySys_ResetWarnOptions`: clear :data:`sys.warnoptions` and
:data:`!warnings.filters` instead.
* :c:func:`Py_GetExecPrefix`: get :data:`sys.exec_prefix` instead.
* :c:func:`Py_GetPath`: get :data:`sys.path` instead.
* :c:func:`Py_GetPrefix`: get :data:`sys.prefix` instead.
* :c:func:`Py_GetProgramFullPath`: get :data:`sys.executable` instead.
* :c:func:`Py_GetProgramName`: get :data:`sys.executable` instead.
* :c:func:`Py_GetPythonHome`: get :c:member:`PyConfig.home` or
:envvar:`PYTHONHOME` environment variable instead.
Pending Removal in Future Versions
----------------------------------
The following APIs were deprecated in earlier Python versions and will be
removed, although there is currently no date scheduled for their removal.
* :c:macro:`Py_TPFLAGS_HAVE_FINALIZE`: no needed since Python 3.8.
* :c:func:`PyErr_Fetch`: use :c:func:`PyErr_GetRaisedException`.
* :c:func:`PyErr_NormalizeException`: use :c:func:`PyErr_GetRaisedException`.
* :c:func:`PyErr_Restore`: use :c:func:`PyErr_SetRaisedException`.
* :c:func:`PyModule_GetFilename`: use :c:func:`PyModule_GetFilenameObject`.
* :c:func:`PyOS_AfterFork`: use :c:func:`PyOS_AfterFork_Child()`.
* :c:func:`PySlice_GetIndicesEx`.
* :c:func:`!PyUnicode_AsDecodedObject`.
* :c:func:`!PyUnicode_AsDecodedUnicode`.
* :c:func:`!PyUnicode_AsEncodedObject`.
* :c:func:`!PyUnicode_AsEncodedUnicode`.
* :c:func:`PyUnicode_READY`: not needed since Python 3.12.
* :c:func:`!_PyErr_ChainExceptions`.
* :c:member:`!PyBytesObject.ob_shash` member:
call :c:func:`PyObject_Hash` instead.
* :c:member:`!PyDictObject.ma_version_tag` member.
* TLS API:
* :c:func:`PyThread_create_key`: use :c:func:`PyThread_tss_alloc`.
* :c:func:`PyThread_delete_key`: use :c:func:`PyThread_tss_free`.
* :c:func:`PyThread_set_key_value`: use :c:func:`PyThread_tss_set`.
* :c:func:`PyThread_get_key_value`: use :c:func:`PyThread_tss_get`.
* :c:func:`PyThread_delete_key_value`: use :c:func:`PyThread_tss_delete`.
* :c:func:`PyThread_ReInitTLS`: no longer needed.
|