forked from pytorch/pytorch.github.io
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathtyping.html
3115 lines (2405 loc) · 328 KB
/
typing.html
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
<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta name="robots" content="noindex">
<meta name="robots" content="noindex">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>typing — PyTorch 1.8.1 documentation</title>
<link rel="canonical" href="https://pytorch.org/docs/stable/_modules/typing.html"/>
<link rel="stylesheet" href="../_static/css/theme.css" type="text/css" />
<!-- <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> -->
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/katex.min.css" type="text/css" />
<link rel="stylesheet" href="../_static/css/jit.css" type="text/css" />
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/katex.min.css" type="text/css" />
<link rel="stylesheet" href="../_static/katex-math.css" type="text/css" />
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<script src="../_static/js/modernizr.min.js"></script>
<!-- Preload the theme fonts -->
<link rel="preload" href="../_static/fonts/FreightSans/freight-sans-book.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="../_static/fonts/FreightSans/freight-sans-medium.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="../_static/fonts/IBMPlexMono/IBMPlexMono-Medium.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="../_static/fonts/FreightSans/freight-sans-bold.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="../_static/fonts/FreightSans/freight-sans-medium-italic.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="../_static/fonts/IBMPlexMono/IBMPlexMono-SemiBold.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<!-- Preload the katex fonts -->
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Math-Italic.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Main-Regular.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Main-Bold.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Size1-Regular.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Size4-Regular.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Size2-Regular.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Size3-Regular.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/fonts/KaTeX_Caligraphic-Regular.woff2" as="font" type="font/woff2" crossorigin="anonymous">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.15.2/css/all.css" integrity="sha384-vSIIfh2YWi9wW0r9iZe7RJPrKwp6bG+s9QZMoITbCckVJqGCCRhc+ccxNcdpHuYu" crossorigin="anonymous">
</head>
<div class="container-fluid header-holder tutorials-header" id="header-holder">
<div class="container">
<div class="header-container">
<a class="header-logo" href="https://pytorch.org/" aria-label="PyTorch"></a>
<div class="main-menu">
<ul>
<li>
<a href="https://pytorch.org/get-started">Get Started</a>
</li>
<li>
<a href="https://pytorch.org/ecosystem">Ecosystem</a>
</li>
<li>
<a href="https://pytorch.org/mobile">Mobile</a>
</li>
<li>
<a href="https://pytorch.org/blog/">Blog</a>
</li>
<li>
<a href="https://pytorch.org/tutorials">Tutorials</a>
</li>
<li class="active">
<div id="resourcesDropdownButton" data-toggle="resources-dropdown" class="resources-dropdown">
<a class="resource-option with-down-orange-arrow">
Docs
</a>
<div class="resources-dropdown-menu">
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/docs/stable/index.html">
<span class="dropdown-title">PyTorch</span>
<p></p>
</a>
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/audio/stable/index.html">
<span class="dropdown-title">torchaudio</span>
<p></p>
</a>
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/text/stable/index.html">
<span class="dropdown-title">torchtext</span>
<p></p>
</a>
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/vision/stable/index.html">
<span class="dropdown-title">torchvision</span>
<p></p>
</a>
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/elastic/">
<span class="dropdown-title">TorchElastic</span>
<p></p>
</a>
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/serve/">
<span class="dropdown-title">TorchServe</span>
<p></p>
</a>
<a class="doc-dropdown-option nav-dropdown-item" href="https://pytorch.org/xla">
<span class="dropdown-title">PyTorch on XLA Devices</span>
<p></p>
</a>
</div>
</li>
<li>
<div id="resourcesDropdownButton" data-toggle="resources-dropdown" class="resources-dropdown">
<a class="resource-option with-down-arrow">
Resources
</a>
<div class="resources-dropdown-menu">
<a class="nav-dropdown-item" href="https://pytorch.org/features">
<span class="dropdown-title">About</span>
<p>Learn about PyTorch’s features and capabilities</p>
</a>
<a class="nav-dropdown-item" href="https://pytorch.org/#community-module">
<span class="dropdown-title">Community</span>
<p>Join the PyTorch developer community to contribute, learn, and get your questions answered.</p>
</a>
<a class="nav-dropdown-item" href="https://pytorch.org/resources">
<span class="dropdown-title">Developer Resources</span>
<p>Find resources and get questions answered</p>
</a>
<a class="nav-dropdown-item" href="https://discuss.pytorch.org/" target="_blank">
<span class="dropdown-title">Forums</span>
<p>A place to discuss PyTorch code, issues, install, research</p>
</a>
<a class="nav-dropdown-item" href="https://pytorch.org/hub">
<span class="dropdown-title">Models (Beta)</span>
<p>Discover, publish, and reuse pre-trained models</p>
</a>
</div>
</div>
</li>
<li>
<a href="https://github.com/pytorch/pytorch">Github</a>
</li>
</ul>
</div>
<a class="main-menu-open-button" href="#" data-behavior="open-mobile-menu"></a>
</div>
</div>
</div>
<body class="pytorch-body">
<div class="table-of-contents-link-wrapper">
<span>Table of Contents</span>
<a href="#" class="toggle-table-of-contents" data-behavior="toggle-table-of-contents"></a>
</div>
<nav data-toggle="wy-nav-shift" class="pytorch-left-menu" id="pytorch-left-menu">
<div class="pytorch-side-scroll">
<div class="pytorch-menu pytorch-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<div class="pytorch-left-menu-search">
<div class="version">
<a href='https://pytorch.org/docs/versions.html'>1.8.1 ▼</a>
</div>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
<input type="text" name="q" placeholder="Search Docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div>
<p class="caption"><span class="caption-text">Notes</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../notes/amp_examples.html">Automatic Mixed Precision examples</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/autograd.html">Autograd mechanics</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/broadcasting.html">Broadcasting semantics</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/cpu_threading_torchscript_inference.html">CPU threading and TorchScript inference</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/cuda.html">CUDA semantics</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/ddp.html">Distributed Data Parallel</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/extending.html">Extending PyTorch</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/faq.html">Frequently Asked Questions</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/large_scale_deployments.html">Features for large-scale deployments</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/modules.html">Modules</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/multiprocessing.html">Multiprocessing best practices</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/randomness.html">Reproducibility</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/serialization.html">Serialization semantics</a></li>
<li class="toctree-l1"><a class="reference internal" href="../notes/windows.html">Windows FAQ</a></li>
</ul>
<p class="caption"><span class="caption-text">Language Bindings</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../cpp_index.html">C++</a></li>
<li class="toctree-l1"><a class="reference external" href="https://pytorch.org/javadoc/">Javadoc</a></li>
</ul>
<p class="caption"><span class="caption-text">Python API</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../torch.html">torch</a></li>
<li class="toctree-l1"><a class="reference internal" href="../nn.html">torch.nn</a></li>
<li class="toctree-l1"><a class="reference internal" href="../nn.functional.html">torch.nn.functional</a></li>
<li class="toctree-l1"><a class="reference internal" href="../tensors.html">torch.Tensor</a></li>
<li class="toctree-l1"><a class="reference internal" href="../tensor_attributes.html">Tensor Attributes</a></li>
<li class="toctree-l1"><a class="reference internal" href="../tensor_view.html">Tensor Views</a></li>
<li class="toctree-l1"><a class="reference internal" href="../autograd.html">torch.autograd</a></li>
<li class="toctree-l1"><a class="reference internal" href="../cuda.html">torch.cuda</a></li>
<li class="toctree-l1"><a class="reference internal" href="../amp.html">torch.cuda.amp</a></li>
<li class="toctree-l1"><a class="reference internal" href="../backends.html">torch.backends</a></li>
<li class="toctree-l1"><a class="reference internal" href="../distributed.html">torch.distributed</a></li>
<li class="toctree-l1"><a class="reference internal" href="../distributions.html">torch.distributions</a></li>
<li class="toctree-l1"><a class="reference internal" href="../fft.html">torch.fft</a></li>
<li class="toctree-l1"><a class="reference internal" href="../futures.html">torch.futures</a></li>
<li class="toctree-l1"><a class="reference internal" href="../fx.html">torch.fx</a></li>
<li class="toctree-l1"><a class="reference internal" href="../hub.html">torch.hub</a></li>
<li class="toctree-l1"><a class="reference internal" href="../jit.html">torch.jit</a></li>
<li class="toctree-l1"><a class="reference internal" href="../linalg.html">torch.linalg</a></li>
<li class="toctree-l1"><a class="reference internal" href="../torch.overrides.html">torch.overrides</a></li>
<li class="toctree-l1"><a class="reference internal" href="../profiler.html">torch.profiler</a></li >
<li class="toctree-l1"><a class="reference internal" href="../nn.init.html">torch.nn.init</a></li>
<li class="toctree-l1"><a class="reference internal" href="../onnx.html">torch.onnx</a></li>
<li class="toctree-l1"><a class="reference internal" href="../optim.html">torch.optim</a></li>
<li class="toctree-l1"><a class="reference internal" href="../complex_numbers.html">Complex Numbers</a></li>
<li class="toctree-l1"><a class="reference internal" href="../ddp_comm_hooks.html">DDP Communication Hooks</a></li>
<li class="toctree-l1"><a class="reference internal" href="../pipeline.html">Pipeline Parallelism</a></li>
<li class="toctree-l1"><a class="reference internal" href="../quantization.html">Quantization</a></li>
<li class="toctree-l1"><a class="reference internal" href="../rpc.html">Distributed RPC Framework</a></li>
<li class="toctree-l1"><a class="reference internal" href="../random.html">torch.random</a></li>
<li class="toctree-l1"><a class="reference internal" href="../sparse.html">torch.sparse</a></li>
<li class="toctree-l1"><a class="reference internal" href="../storage.html">torch.Storage</a></li>
<li class="toctree-l1"><a class="reference internal" href="../benchmark_utils.html">torch.utils.benchmark</a></li>
<li class="toctree-l1"><a class="reference internal" href="../bottleneck.html">torch.utils.bottleneck</a></li>
<li class="toctree-l1"><a class="reference internal" href="../checkpoint.html">torch.utils.checkpoint</a></li>
<li class="toctree-l1"><a class="reference internal" href="../cpp_extension.html">torch.utils.cpp_extension</a></li>
<li class="toctree-l1"><a class="reference internal" href="../data.html">torch.utils.data</a></li>
<li class="toctree-l1"><a class="reference internal" href="../dlpack.html">torch.utils.dlpack</a></li>
<li class="toctree-l1"><a class="reference internal" href="../mobile_optimizer.html">torch.utils.mobile_optimizer</a></li>
<li class="toctree-l1"><a class="reference internal" href="../model_zoo.html">torch.utils.model_zoo</a></li>
<li class="toctree-l1"><a class="reference internal" href="../tensorboard.html">torch.utils.tensorboard</a></li>
<li class="toctree-l1"><a class="reference internal" href="../type_info.html">Type Info</a></li>
<li class="toctree-l1"><a class="reference internal" href="../named_tensor.html">Named Tensors</a></li>
<li class="toctree-l1"><a class="reference internal" href="../name_inference.html">Named Tensors operator coverage</a></li>
<li class="toctree-l1"><a class="reference internal" href="../__config__.html">torch.__config__</a></li>
</ul>
<p class="caption"><span class="caption-text">Libraries</span></p>
<ul>
<li class="toctree-l1"><a class="reference external" href="https://pytorch.org/audio/stable">torchaudio</a></li>
<li class="toctree-l1"><a class="reference external" href="https://pytorch.org/text/stable">torchtext</a></li>
<li class="toctree-l1"><a class="reference external" href="https://pytorch.org/vision/stable">torchvision</a></li>
<li class="toctree-l1"><a class="reference external" href="https://pytorch.org/elastic/">TorchElastic</a></li>
<li class="toctree-l1"><a class="reference external" href="https://pytorch.org/serve">TorchServe</a></li>
<li class="toctree-l1"><a class="reference external" href="http://pytorch.org/xla/">PyTorch on XLA Devices</a></li>
</ul>
<p class="caption"><span class="caption-text">Community</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../community/contribution_guide.html">PyTorch Contribution Guide</a></li>
<li class="toctree-l1"><a class="reference internal" href="../community/governance.html">PyTorch Governance</a></li>
<li class="toctree-l1"><a class="reference internal" href="../community/persons_of_interest.html">PyTorch Governance | Persons of Interest</a></li>
</ul>
</div>
</div>
</nav>
<div class="pytorch-container">
<div class="pytorch-page-level-bar" id="pytorch-page-level-bar">
<div class="pytorch-breadcrumbs-wrapper">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="pytorch-breadcrumbs">
<li>
<a href="../index.html">
Docs
</a> >
</li>
<li><a href="index.html">Module code</a> ></li>
<li>typing</li>
<li class="pytorch-breadcrumbs-aside">
</li>
</ul>
</div>
</div>
<div class="pytorch-shortcuts-wrapper" id="pytorch-shortcuts-wrapper">
Shortcuts
</div>
</div>
<section data-toggle="wy-nav-shift" id="pytorch-content-wrap" class="pytorch-content-wrap">
<div class="pytorch-content-left">
<div class="rst-content">
<div role="main" class="main-content" itemscope="itemscope" itemtype="http://schema.org/Article">
<article itemprop="articleBody" id="pytorch-article" class="pytorch-article">
<h1>Source code for typing</h1><div class="highlight"><pre>
<span></span><span class="kn">import</span> <span class="nn">abc</span>
<span class="kn">from</span> <span class="nn">abc</span> <span class="kn">import</span> <span class="n">abstractmethod</span><span class="p">,</span> <span class="n">abstractproperty</span>
<span class="kn">import</span> <span class="nn">collections</span>
<span class="kn">import</span> <span class="nn">contextlib</span>
<span class="kn">import</span> <span class="nn">functools</span>
<span class="kn">import</span> <span class="nn">re</span> <span class="k">as</span> <span class="nn">stdlib_re</span> <span class="c1"># Avoid confusion with the re we export.</span>
<span class="kn">import</span> <span class="nn">sys</span>
<span class="kn">import</span> <span class="nn">types</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">import</span> <span class="nn">collections.abc</span> <span class="k">as</span> <span class="nn">collections_abc</span>
<span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
<span class="kn">import</span> <span class="nn">collections</span> <span class="k">as</span> <span class="nn">collections_abc</span> <span class="c1"># Fallback for PY3.2.</span>
<span class="k">if</span> <span class="n">sys</span><span class="o">.</span><span class="n">version_info</span><span class="p">[:</span><span class="mi">2</span><span class="p">]</span> <span class="o">>=</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="mi">6</span><span class="p">):</span>
<span class="kn">import</span> <span class="nn">_collections_abc</span> <span class="c1"># Needed for private function _check_methods # noqa</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">from</span> <span class="nn">types</span> <span class="kn">import</span> <span class="n">WrapperDescriptorType</span><span class="p">,</span> <span class="n">MethodWrapperType</span><span class="p">,</span> <span class="n">MethodDescriptorType</span>
<span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
<span class="n">WrapperDescriptorType</span> <span class="o">=</span> <span class="nb">type</span><span class="p">(</span><span class="nb">object</span><span class="o">.</span><span class="fm">__init__</span><span class="p">)</span>
<span class="n">MethodWrapperType</span> <span class="o">=</span> <span class="nb">type</span><span class="p">(</span><span class="nb">object</span><span class="p">()</span><span class="o">.</span><span class="fm">__str__</span><span class="p">)</span>
<span class="n">MethodDescriptorType</span> <span class="o">=</span> <span class="nb">type</span><span class="p">(</span><span class="nb">str</span><span class="o">.</span><span class="n">join</span><span class="p">)</span>
<span class="c1"># Please keep __all__ alphabetized within each category.</span>
<span class="n">__all__</span> <span class="o">=</span> <span class="p">[</span>
<span class="c1"># Super-special typing primitives.</span>
<span class="s1">'Any'</span><span class="p">,</span>
<span class="s1">'Callable'</span><span class="p">,</span>
<span class="s1">'ClassVar'</span><span class="p">,</span>
<span class="s1">'Generic'</span><span class="p">,</span>
<span class="s1">'Optional'</span><span class="p">,</span>
<span class="s1">'Tuple'</span><span class="p">,</span>
<span class="s1">'Type'</span><span class="p">,</span>
<span class="s1">'TypeVar'</span><span class="p">,</span>
<span class="s1">'Union'</span><span class="p">,</span>
<span class="c1"># ABCs (from collections.abc).</span>
<span class="s1">'AbstractSet'</span><span class="p">,</span> <span class="c1"># collections.abc.Set.</span>
<span class="s1">'GenericMeta'</span><span class="p">,</span> <span class="c1"># subclass of abc.ABCMeta and a metaclass</span>
<span class="c1"># for 'Generic' and ABCs below.</span>
<span class="s1">'ByteString'</span><span class="p">,</span>
<span class="s1">'Container'</span><span class="p">,</span>
<span class="s1">'ContextManager'</span><span class="p">,</span>
<span class="s1">'Hashable'</span><span class="p">,</span>
<span class="s1">'ItemsView'</span><span class="p">,</span>
<span class="s1">'Iterable'</span><span class="p">,</span>
<span class="s1">'Iterator'</span><span class="p">,</span>
<span class="s1">'KeysView'</span><span class="p">,</span>
<span class="s1">'Mapping'</span><span class="p">,</span>
<span class="s1">'MappingView'</span><span class="p">,</span>
<span class="s1">'MutableMapping'</span><span class="p">,</span>
<span class="s1">'MutableSequence'</span><span class="p">,</span>
<span class="s1">'MutableSet'</span><span class="p">,</span>
<span class="s1">'Sequence'</span><span class="p">,</span>
<span class="s1">'Sized'</span><span class="p">,</span>
<span class="s1">'ValuesView'</span><span class="p">,</span>
<span class="c1"># The following are added depending on presence</span>
<span class="c1"># of their non-generic counterparts in stdlib:</span>
<span class="c1"># Awaitable,</span>
<span class="c1"># AsyncIterator,</span>
<span class="c1"># AsyncIterable,</span>
<span class="c1"># Coroutine,</span>
<span class="c1"># Collection,</span>
<span class="c1"># AsyncGenerator,</span>
<span class="c1"># AsyncContextManager</span>
<span class="c1"># Structural checks, a.k.a. protocols.</span>
<span class="s1">'Reversible'</span><span class="p">,</span>
<span class="s1">'SupportsAbs'</span><span class="p">,</span>
<span class="s1">'SupportsBytes'</span><span class="p">,</span>
<span class="s1">'SupportsComplex'</span><span class="p">,</span>
<span class="s1">'SupportsFloat'</span><span class="p">,</span>
<span class="s1">'SupportsInt'</span><span class="p">,</span>
<span class="s1">'SupportsRound'</span><span class="p">,</span>
<span class="c1"># Concrete collection types.</span>
<span class="s1">'Counter'</span><span class="p">,</span>
<span class="s1">'Deque'</span><span class="p">,</span>
<span class="s1">'Dict'</span><span class="p">,</span>
<span class="s1">'DefaultDict'</span><span class="p">,</span>
<span class="s1">'List'</span><span class="p">,</span>
<span class="s1">'Set'</span><span class="p">,</span>
<span class="s1">'FrozenSet'</span><span class="p">,</span>
<span class="s1">'NamedTuple'</span><span class="p">,</span> <span class="c1"># Not really a type.</span>
<span class="s1">'Generator'</span><span class="p">,</span>
<span class="c1"># One-off things.</span>
<span class="s1">'AnyStr'</span><span class="p">,</span>
<span class="s1">'cast'</span><span class="p">,</span>
<span class="s1">'get_type_hints'</span><span class="p">,</span>
<span class="s1">'NewType'</span><span class="p">,</span>
<span class="s1">'no_type_check'</span><span class="p">,</span>
<span class="s1">'no_type_check_decorator'</span><span class="p">,</span>
<span class="s1">'overload'</span><span class="p">,</span>
<span class="s1">'Text'</span><span class="p">,</span>
<span class="s1">'TYPE_CHECKING'</span><span class="p">,</span>
<span class="p">]</span>
<span class="c1"># The pseudo-submodules 're' and 'io' are part of the public</span>
<span class="c1"># namespace, but excluded from __all__ because they might stomp on</span>
<span class="c1"># legitimate imports of those modules.</span>
<span class="k">def</span> <span class="nf">_qualname</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">if</span> <span class="n">sys</span><span class="o">.</span><span class="n">version_info</span><span class="p">[:</span><span class="mi">2</span><span class="p">]</span> <span class="o">>=</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="mi">3</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span><span class="o">.</span><span class="vm">__qualname__</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># Fall back to just name.</span>
<span class="k">return</span> <span class="n">x</span><span class="o">.</span><span class="vm">__name__</span>
<span class="k">def</span> <span class="nf">_trim_name</span><span class="p">(</span><span class="n">nm</span><span class="p">):</span>
<span class="n">whitelist</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'_TypeAlias'</span><span class="p">,</span> <span class="s1">'_ForwardRef'</span><span class="p">,</span> <span class="s1">'_TypingBase'</span><span class="p">,</span> <span class="s1">'_FinalTypingBase'</span><span class="p">)</span>
<span class="k">if</span> <span class="n">nm</span><span class="o">.</span><span class="n">startswith</span><span class="p">(</span><span class="s1">'_'</span><span class="p">)</span> <span class="ow">and</span> <span class="n">nm</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">whitelist</span><span class="p">:</span>
<span class="n">nm</span> <span class="o">=</span> <span class="n">nm</span><span class="p">[</span><span class="mi">1</span><span class="p">:]</span>
<span class="k">return</span> <span class="n">nm</span>
<span class="k">class</span> <span class="nc">TypingMeta</span><span class="p">(</span><span class="nb">type</span><span class="p">):</span>
<span class="sd">"""Metaclass for most types defined in typing module</span>
<span class="sd"> (not a part of public API).</span>
<span class="sd"> This overrides __new__() to require an extra keyword parameter</span>
<span class="sd"> '_root', which serves as a guard against naive subclassing of the</span>
<span class="sd"> typing classes. Any legitimate class defined using a metaclass</span>
<span class="sd"> derived from TypingMeta must pass _root=True.</span>
<span class="sd"> This also defines a dummy constructor (all the work for most typing</span>
<span class="sd"> constructs is done in __new__) and a nicer repr().</span>
<span class="sd"> """</span>
<span class="n">_is_protocol</span> <span class="o">=</span> <span class="kc">False</span>
<span class="k">def</span> <span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="n">name</span><span class="p">,</span> <span class="n">bases</span><span class="p">,</span> <span class="n">namespace</span><span class="p">,</span> <span class="o">*</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">_root</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Cannot subclass </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span>
<span class="p">(</span><span class="s1">', '</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="nb">map</span><span class="p">(</span><span class="n">_type_repr</span><span class="p">,</span> <span class="n">bases</span><span class="p">))</span> <span class="ow">or</span> <span class="s1">'()'</span><span class="p">))</span>
<span class="k">return</span> <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="n">name</span><span class="p">,</span> <span class="n">bases</span><span class="p">,</span> <span class="n">namespace</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwds</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="nf">_eval_type</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">globalns</span><span class="p">,</span> <span class="n">localns</span><span class="p">):</span>
<span class="sd">"""Override this in subclasses to interpret forward references.</span>
<span class="sd"> For example, List['C'] is internally stored as</span>
<span class="sd"> List[_ForwardRef('C')], which should evaluate to List[C],</span>
<span class="sd"> where C is an object found in globalns or localns (searching</span>
<span class="sd"> localns first, of course).</span>
<span class="sd"> """</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">def</span> <span class="nf">_get_type_vars</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tvars</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="fm">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">qname</span> <span class="o">=</span> <span class="n">_trim_name</span><span class="p">(</span><span class="n">_qualname</span><span class="p">(</span><span class="bp">self</span><span class="p">))</span>
<span class="k">return</span> <span class="s1">'</span><span class="si">%s</span><span class="s1">.</span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="vm">__module__</span><span class="p">,</span> <span class="n">qname</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">_TypingBase</span><span class="p">(</span><span class="n">metaclass</span><span class="o">=</span><span class="n">TypingMeta</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Internal indicator of special typing constructs."""</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'__weakref__'</span><span class="p">,)</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwds</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwds</span><span class="p">):</span>
<span class="sd">"""Constructor.</span>
<span class="sd"> This only exists to give a better error message in case</span>
<span class="sd"> someone tries to subclass a special typing object (not a good idea).</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">args</span><span class="p">)</span> <span class="o">==</span> <span class="mi">3</span> <span class="ow">and</span>
<span class="nb">isinstance</span><span class="p">(</span><span class="n">args</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="nb">str</span><span class="p">)</span> <span class="ow">and</span>
<span class="nb">isinstance</span><span class="p">(</span><span class="n">args</span><span class="p">[</span><span class="mi">1</span><span class="p">],</span> <span class="nb">tuple</span><span class="p">)):</span>
<span class="c1"># Close enough.</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Cannot subclass </span><span class="si">%r</span><span class="s2">"</span> <span class="o">%</span> <span class="bp">cls</span><span class="p">)</span>
<span class="k">return</span> <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">)</span>
<span class="c1"># Things that are not classes also need these.</span>
<span class="k">def</span> <span class="nf">_eval_type</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">globalns</span><span class="p">,</span> <span class="n">localns</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">def</span> <span class="nf">_get_type_vars</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tvars</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="fm">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="bp">cls</span> <span class="o">=</span> <span class="nb">type</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">qname</span> <span class="o">=</span> <span class="n">_trim_name</span><span class="p">(</span><span class="n">_qualname</span><span class="p">(</span><span class="bp">cls</span><span class="p">))</span>
<span class="k">return</span> <span class="s1">'</span><span class="si">%s</span><span class="s1">.</span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="bp">cls</span><span class="o">.</span><span class="vm">__module__</span><span class="p">,</span> <span class="n">qname</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__call__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwds</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Cannot instantiate </span><span class="si">%r</span><span class="s2">"</span> <span class="o">%</span> <span class="nb">type</span><span class="p">(</span><span class="bp">self</span><span class="p">))</span>
<span class="k">class</span> <span class="nc">_FinalTypingBase</span><span class="p">(</span><span class="n">_TypingBase</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Internal mix-in class to prevent instantiation.</span>
<span class="sd"> Prevents instantiation unless _root=True is given in class call.</span>
<span class="sd"> It is used to create pseudo-singleton instances Any, Union, Optional, etc.</span>
<span class="sd"> """</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">()</span>
<span class="k">def</span> <span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="o">**</span><span class="n">kwds</span><span class="p">):</span>
<span class="bp">self</span> <span class="o">=</span> <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwds</span><span class="p">)</span>
<span class="k">if</span> <span class="n">_root</span> <span class="ow">is</span> <span class="kc">True</span><span class="p">:</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Cannot instantiate </span><span class="si">%r</span><span class="s2">"</span> <span class="o">%</span> <span class="bp">cls</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__reduce__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="n">_trim_name</span><span class="p">(</span><span class="nb">type</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="vm">__name__</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">_ForwardRef</span><span class="p">(</span><span class="n">_TypingBase</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Internal wrapper to hold a forward reference."""</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'__forward_arg__'</span><span class="p">,</span> <span class="s1">'__forward_code__'</span><span class="p">,</span>
<span class="s1">'__forward_evaluated__'</span><span class="p">,</span> <span class="s1">'__forward_value__'</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">arg</span><span class="p">):</span>
<span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="nb">str</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s1">'Forward reference must be a string -- got </span><span class="si">%r</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">arg</span><span class="p">,))</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">code</span> <span class="o">=</span> <span class="nb">compile</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="s1">'<string>'</span><span class="p">,</span> <span class="s1">'eval'</span><span class="p">)</span>
<span class="k">except</span> <span class="ne">SyntaxError</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">SyntaxError</span><span class="p">(</span><span class="s1">'Forward reference must be an expression -- got </span><span class="si">%r</span><span class="s1">'</span> <span class="o">%</span>
<span class="p">(</span><span class="n">arg</span><span class="p">,))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_arg__</span> <span class="o">=</span> <span class="n">arg</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_code__</span> <span class="o">=</span> <span class="n">code</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_evaluated__</span> <span class="o">=</span> <span class="kc">False</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_value__</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">def</span> <span class="nf">_eval_type</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">globalns</span><span class="p">,</span> <span class="n">localns</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">__forward_evaluated__</span> <span class="ow">or</span> <span class="n">localns</span> <span class="ow">is</span> <span class="ow">not</span> <span class="n">globalns</span><span class="p">:</span>
<span class="k">if</span> <span class="n">globalns</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">localns</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">globalns</span> <span class="o">=</span> <span class="n">localns</span> <span class="o">=</span> <span class="p">{}</span>
<span class="k">elif</span> <span class="n">globalns</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">globalns</span> <span class="o">=</span> <span class="n">localns</span>
<span class="k">elif</span> <span class="n">localns</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">localns</span> <span class="o">=</span> <span class="n">globalns</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_value__</span> <span class="o">=</span> <span class="n">_type_check</span><span class="p">(</span>
<span class="nb">eval</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__forward_code__</span><span class="p">,</span> <span class="n">globalns</span><span class="p">,</span> <span class="n">localns</span><span class="p">),</span>
<span class="s2">"Forward references must evaluate to types."</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_evaluated__</span> <span class="o">=</span> <span class="kc">True</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__forward_value__</span>
<span class="k">def</span> <span class="fm">__eq__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="n">_ForwardRef</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">NotImplemented</span>
<span class="k">return</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__forward_arg__</span> <span class="o">==</span> <span class="n">other</span><span class="o">.</span><span class="n">__forward_arg__</span> <span class="ow">and</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__forward_value__</span> <span class="o">==</span> <span class="n">other</span><span class="o">.</span><span class="n">__forward_value__</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__hash__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="nb">hash</span><span class="p">((</span><span class="bp">self</span><span class="o">.</span><span class="n">__forward_arg__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">__forward_value__</span><span class="p">))</span>
<span class="k">def</span> <span class="fm">__instancecheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Forward references cannot be used with isinstance()."</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__subclasscheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="bp">cls</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Forward references cannot be used with issubclass()."</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s1">'_ForwardRef(</span><span class="si">%r</span><span class="s1">)'</span> <span class="o">%</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__forward_arg__</span><span class="p">,)</span>
<span class="k">class</span> <span class="nc">_TypeAlias</span><span class="p">(</span><span class="n">_TypingBase</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Internal helper class for defining generic variants of concrete types.</span>
<span class="sd"> Note that this is not a type; let's call it a pseudo-type. It cannot</span>
<span class="sd"> be used in instance and subclass checks in parameterized form, i.e.</span>
<span class="sd"> ``isinstance(42, Match[str])`` raises ``TypeError`` instead of returning</span>
<span class="sd"> ``False``.</span>
<span class="sd"> """</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'name'</span><span class="p">,</span> <span class="s1">'type_var'</span><span class="p">,</span> <span class="s1">'impl_type'</span><span class="p">,</span> <span class="s1">'type_checker'</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">name</span><span class="p">,</span> <span class="n">type_var</span><span class="p">,</span> <span class="n">impl_type</span><span class="p">,</span> <span class="n">type_checker</span><span class="p">):</span>
<span class="sd">"""Initializer.</span>
<span class="sd"> Args:</span>
<span class="sd"> name: The name, e.g. 'Pattern'.</span>
<span class="sd"> type_var: The type parameter, e.g. AnyStr, or the</span>
<span class="sd"> specific type, e.g. str.</span>
<span class="sd"> impl_type: The implementation type.</span>
<span class="sd"> type_checker: Function that takes an impl_type instance.</span>
<span class="sd"> and returns a value that should be a type_var instance.</span>
<span class="sd"> """</span>
<span class="k">assert</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="nb">str</span><span class="p">),</span> <span class="nb">repr</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="k">assert</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">impl_type</span><span class="p">,</span> <span class="nb">type</span><span class="p">),</span> <span class="nb">repr</span><span class="p">(</span><span class="n">impl_type</span><span class="p">)</span>
<span class="k">assert</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">impl_type</span><span class="p">,</span> <span class="n">TypingMeta</span><span class="p">),</span> <span class="nb">repr</span><span class="p">(</span><span class="n">impl_type</span><span class="p">)</span>
<span class="k">assert</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">type_var</span><span class="p">,</span> <span class="p">(</span><span class="nb">type</span><span class="p">,</span> <span class="n">_TypingBase</span><span class="p">)),</span> <span class="nb">repr</span><span class="p">(</span><span class="n">type_var</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">name</span> <span class="o">=</span> <span class="n">name</span>
<span class="bp">self</span><span class="o">.</span><span class="n">type_var</span> <span class="o">=</span> <span class="n">type_var</span>
<span class="bp">self</span><span class="o">.</span><span class="n">impl_type</span> <span class="o">=</span> <span class="n">impl_type</span>
<span class="bp">self</span><span class="o">.</span><span class="n">type_checker</span> <span class="o">=</span> <span class="n">type_checker</span>
<span class="k">def</span> <span class="fm">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">%s</span><span class="s2">[</span><span class="si">%s</span><span class="s2">]"</span> <span class="o">%</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="n">_type_repr</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">))</span>
<span class="k">def</span> <span class="fm">__getitem__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parameter</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">,</span> <span class="n">TypeVar</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"</span><span class="si">%s</span><span class="s2"> cannot be further parameterized."</span> <span class="o">%</span> <span class="bp">self</span><span class="p">)</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="o">.</span><span class="n">__constraints__</span> <span class="ow">and</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">parameter</span><span class="p">,</span> <span class="nb">type</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">issubclass</span><span class="p">(</span><span class="n">parameter</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="o">.</span><span class="n">__constraints__</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"</span><span class="si">%s</span><span class="s2"> is not a valid substitution for </span><span class="si">%s</span><span class="s2">."</span> <span class="o">%</span>
<span class="p">(</span><span class="n">parameter</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">))</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">parameter</span><span class="p">,</span> <span class="n">TypeVar</span><span class="p">)</span> <span class="ow">and</span> <span class="n">parameter</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"</span><span class="si">%s</span><span class="s2"> cannot be re-parameterized."</span> <span class="o">%</span> <span class="bp">self</span><span class="p">)</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="vm">__class__</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="n">parameter</span><span class="p">,</span>
<span class="bp">self</span><span class="o">.</span><span class="n">impl_type</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_checker</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__eq__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="n">_TypeAlias</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">NotImplemented</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">name</span> <span class="o">==</span> <span class="n">other</span><span class="o">.</span><span class="n">name</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_var</span> <span class="o">==</span> <span class="n">other</span><span class="o">.</span><span class="n">type_var</span>
<span class="k">def</span> <span class="fm">__hash__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="nb">hash</span><span class="p">((</span><span class="bp">self</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">))</span>
<span class="k">def</span> <span class="fm">__instancecheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">,</span> <span class="n">TypeVar</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Parameterized type aliases cannot be used "</span>
<span class="s2">"with isinstance()."</span><span class="p">)</span>
<span class="k">return</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">impl_type</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__subclasscheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="bp">cls</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">type_var</span><span class="p">,</span> <span class="n">TypeVar</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Parameterized type aliases cannot be used "</span>
<span class="s2">"with issubclass()."</span><span class="p">)</span>
<span class="k">return</span> <span class="nb">issubclass</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">impl_type</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_get_type_vars</span><span class="p">(</span><span class="n">types</span><span class="p">,</span> <span class="n">tvars</span><span class="p">):</span>
<span class="k">for</span> <span class="n">t</span> <span class="ow">in</span> <span class="n">types</span><span class="p">:</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">t</span><span class="p">,</span> <span class="n">TypingMeta</span><span class="p">)</span> <span class="ow">or</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">t</span><span class="p">,</span> <span class="n">_TypingBase</span><span class="p">):</span>
<span class="n">t</span><span class="o">.</span><span class="n">_get_type_vars</span><span class="p">(</span><span class="n">tvars</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_type_vars</span><span class="p">(</span><span class="n">types</span><span class="p">):</span>
<span class="n">tvars</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">_get_type_vars</span><span class="p">(</span><span class="n">types</span><span class="p">,</span> <span class="n">tvars</span><span class="p">)</span>
<span class="k">return</span> <span class="nb">tuple</span><span class="p">(</span><span class="n">tvars</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_eval_type</span><span class="p">(</span><span class="n">t</span><span class="p">,</span> <span class="n">globalns</span><span class="p">,</span> <span class="n">localns</span><span class="p">):</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">t</span><span class="p">,</span> <span class="n">TypingMeta</span><span class="p">)</span> <span class="ow">or</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">t</span><span class="p">,</span> <span class="n">_TypingBase</span><span class="p">):</span>
<span class="k">return</span> <span class="n">t</span><span class="o">.</span><span class="n">_eval_type</span><span class="p">(</span><span class="n">globalns</span><span class="p">,</span> <span class="n">localns</span><span class="p">)</span>
<span class="k">return</span> <span class="n">t</span>
<span class="k">def</span> <span class="nf">_type_check</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">msg</span><span class="p">):</span>
<span class="sd">"""Check that the argument is a type, and return it (internal helper).</span>
<span class="sd"> As a special case, accept None and return type(None) instead.</span>
<span class="sd"> Also, _TypeAlias instances (e.g. Match, Pattern) are acceptable.</span>
<span class="sd"> The msg argument is a human-readable error message, e.g.</span>
<span class="sd"> "Union[arg, ...]: arg should be a type."</span>
<span class="sd"> We append the repr() of the actual value (truncated to 100 chars).</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="n">arg</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">return</span> <span class="nb">type</span><span class="p">(</span><span class="kc">None</span><span class="p">)</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="nb">str</span><span class="p">):</span>
<span class="n">arg</span> <span class="o">=</span> <span class="n">_ForwardRef</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span>
<span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">_TypingBase</span><span class="p">)</span> <span class="ow">and</span> <span class="nb">type</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span><span class="o">.</span><span class="vm">__name__</span> <span class="o">==</span> <span class="s1">'_ClassVar'</span> <span class="ow">or</span>
<span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="p">(</span><span class="nb">type</span><span class="p">,</span> <span class="n">_TypingBase</span><span class="p">))</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">callable</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span>
<span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="n">msg</span> <span class="o">+</span> <span class="s2">" Got </span><span class="si">%.100r</span><span class="s2">."</span> <span class="o">%</span> <span class="p">(</span><span class="n">arg</span><span class="p">,))</span>
<span class="c1"># Bare Union etc. are not valid as type arguments</span>
<span class="k">if</span> <span class="p">(</span>
<span class="nb">type</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span><span class="o">.</span><span class="vm">__name__</span> <span class="ow">in</span> <span class="p">(</span><span class="s1">'_Union'</span><span class="p">,</span> <span class="s1">'_Optional'</span><span class="p">)</span> <span class="ow">and</span>
<span class="ow">not</span> <span class="nb">getattr</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="s1">'__origin__'</span><span class="p">,</span> <span class="kc">None</span><span class="p">)</span> <span class="ow">or</span>
<span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">TypingMeta</span><span class="p">)</span> <span class="ow">and</span> <span class="n">arg</span><span class="o">.</span><span class="n">_gorg</span> <span class="ow">in</span> <span class="p">(</span><span class="n">Generic</span><span class="p">,</span> <span class="n">_Protocol</span><span class="p">)</span>
<span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Plain </span><span class="si">%s</span><span class="s2"> is not valid as type argument"</span> <span class="o">%</span> <span class="n">arg</span><span class="p">)</span>
<span class="k">return</span> <span class="n">arg</span>
<span class="k">def</span> <span class="nf">_type_repr</span><span class="p">(</span><span class="n">obj</span><span class="p">):</span>
<span class="sd">"""Return the repr() of an object, special-casing types (internal helper).</span>
<span class="sd"> If obj is a type, we return a shorter version than the default</span>
<span class="sd"> type.__repr__, based on the module and qualified name, which is</span>
<span class="sd"> typically enough to uniquely identify a type. For everything</span>
<span class="sd"> else, we fall back on repr(obj).</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="nb">type</span><span class="p">)</span> <span class="ow">and</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="n">TypingMeta</span><span class="p">):</span>
<span class="k">if</span> <span class="n">obj</span><span class="o">.</span><span class="vm">__module__</span> <span class="o">==</span> <span class="s1">'builtins'</span><span class="p">:</span>
<span class="k">return</span> <span class="n">_qualname</span><span class="p">(</span><span class="n">obj</span><span class="p">)</span>
<span class="k">return</span> <span class="s1">'</span><span class="si">%s</span><span class="s1">.</span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">obj</span><span class="o">.</span><span class="vm">__module__</span><span class="p">,</span> <span class="n">_qualname</span><span class="p">(</span><span class="n">obj</span><span class="p">))</span>
<span class="k">if</span> <span class="n">obj</span> <span class="ow">is</span> <span class="o">...</span><span class="p">:</span>
<span class="k">return</span><span class="p">(</span><span class="s1">'...'</span><span class="p">)</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="n">types</span><span class="o">.</span><span class="n">FunctionType</span><span class="p">):</span>
<span class="k">return</span> <span class="n">obj</span><span class="o">.</span><span class="vm">__name__</span>
<span class="k">return</span> <span class="nb">repr</span><span class="p">(</span><span class="n">obj</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">_Any</span><span class="p">(</span><span class="n">_FinalTypingBase</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Special type indicating an unconstrained type.</span>
<span class="sd"> - Any is compatible with every type.</span>
<span class="sd"> - Any assumed to have all methods.</span>
<span class="sd"> - All values assumed to be instances of Any.</span>
<span class="sd"> Note that all the above statements are true from the point of view of</span>
<span class="sd"> static type checkers. At runtime, Any should not be used with instance</span>
<span class="sd"> or class checks.</span>
<span class="sd"> """</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">()</span>
<span class="k">def</span> <span class="fm">__instancecheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Any cannot be used with isinstance()."</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__subclasscheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="bp">cls</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Any cannot be used with issubclass()."</span><span class="p">)</span>
<span class="n">Any</span> <span class="o">=</span> <span class="n">_Any</span><span class="p">(</span><span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">_NoReturn</span><span class="p">(</span><span class="n">_FinalTypingBase</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Special type indicating functions that never return.</span>
<span class="sd"> Example::</span>
<span class="sd"> from typing import NoReturn</span>
<span class="sd"> def stop() -> NoReturn:</span>
<span class="sd"> raise Exception('no way')</span>
<span class="sd"> This type is invalid in other positions, e.g., ``List[NoReturn]``</span>
<span class="sd"> will fail in static type checkers.</span>
<span class="sd"> """</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">()</span>
<span class="k">def</span> <span class="fm">__instancecheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"NoReturn cannot be used with isinstance()."</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__subclasscheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="bp">cls</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"NoReturn cannot be used with issubclass()."</span><span class="p">)</span>
<span class="n">NoReturn</span> <span class="o">=</span> <span class="n">_NoReturn</span><span class="p">(</span><span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">TypeVar</span><span class="p">(</span><span class="n">_TypingBase</span><span class="p">,</span> <span class="n">_root</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""Type variable.</span>
<span class="sd"> Usage::</span>
<span class="sd"> T = TypeVar('T') # Can be anything</span>
<span class="sd"> A = TypeVar('A', str, bytes) # Must be str or bytes</span>
<span class="sd"> Type variables exist primarily for the benefit of static type</span>
<span class="sd"> checkers. They serve as the parameters for generic types as well</span>
<span class="sd"> as for generic function definitions. See class Generic for more</span>
<span class="sd"> information on generic types. Generic functions work as follows:</span>
<span class="sd"> def repeat(x: T, n: int) -> List[T]:</span>
<span class="sd"> '''Return a list containing n references to x.'''</span>
<span class="sd"> return [x]*n</span>
<span class="sd"> def longest(x: A, y: A) -> A:</span>
<span class="sd"> '''Return the longest of two strings.'''</span>
<span class="sd"> return x if len(x) >= len(y) else y</span>
<span class="sd"> The latter example's signature is essentially the overloading</span>
<span class="sd"> of (str, str) -> str and (bytes, bytes) -> bytes. Also note</span>
<span class="sd"> that if the arguments are instances of some subclass of str,</span>
<span class="sd"> the return type is still plain str.</span>
<span class="sd"> At runtime, isinstance(x, T) and issubclass(C, T) will raise TypeError.</span>
<span class="sd"> Type variables defined with covariant=True or contravariant=True</span>
<span class="sd"> can be used do declare covariant or contravariant generic types.</span>
<span class="sd"> See PEP 484 for more details. By default generic types are invariant</span>
<span class="sd"> in all type variables.</span>
<span class="sd"> Type variables can be introspected. e.g.:</span>
<span class="sd"> T.__name__ == 'T'</span>
<span class="sd"> T.__constraints__ == ()</span>
<span class="sd"> T.__covariant__ == False</span>
<span class="sd"> T.__contravariant__ = False</span>
<span class="sd"> A.__constraints__ == (str, bytes)</span>
<span class="sd"> """</span>
<span class="vm">__slots__</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'__name__'</span><span class="p">,</span> <span class="s1">'__bound__'</span><span class="p">,</span> <span class="s1">'__constraints__'</span><span class="p">,</span>
<span class="s1">'__covariant__'</span><span class="p">,</span> <span class="s1">'__contravariant__'</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">name</span><span class="p">,</span> <span class="o">*</span><span class="n">constraints</span><span class="p">,</span> <span class="n">bound</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span>
<span class="n">covariant</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">contravariant</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="o">*</span><span class="n">constraints</span><span class="p">,</span> <span class="n">bound</span><span class="o">=</span><span class="n">bound</span><span class="p">,</span>
<span class="n">covariant</span><span class="o">=</span><span class="n">covariant</span><span class="p">,</span> <span class="n">contravariant</span><span class="o">=</span><span class="n">contravariant</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="vm">__name__</span> <span class="o">=</span> <span class="n">name</span>
<span class="k">if</span> <span class="n">covariant</span> <span class="ow">and</span> <span class="n">contravariant</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Bivariant types are not supported."</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__covariant__</span> <span class="o">=</span> <span class="nb">bool</span><span class="p">(</span><span class="n">covariant</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__contravariant__</span> <span class="o">=</span> <span class="nb">bool</span><span class="p">(</span><span class="n">contravariant</span><span class="p">)</span>
<span class="k">if</span> <span class="n">constraints</span> <span class="ow">and</span> <span class="n">bound</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Constraints cannot be combined with bound=..."</span><span class="p">)</span>
<span class="k">if</span> <span class="n">constraints</span> <span class="ow">and</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraints</span><span class="p">)</span> <span class="o">==</span> <span class="mi">1</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"A single constraint is not allowed"</span><span class="p">)</span>
<span class="n">msg</span> <span class="o">=</span> <span class="s2">"TypeVar(name, constraint, ...): constraints must be types."</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__constraints__</span> <span class="o">=</span> <span class="nb">tuple</span><span class="p">(</span><span class="n">_type_check</span><span class="p">(</span><span class="n">t</span><span class="p">,</span> <span class="n">msg</span><span class="p">)</span> <span class="k">for</span> <span class="n">t</span> <span class="ow">in</span> <span class="n">constraints</span><span class="p">)</span>
<span class="k">if</span> <span class="n">bound</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__bound__</span> <span class="o">=</span> <span class="n">_type_check</span><span class="p">(</span><span class="n">bound</span><span class="p">,</span> <span class="s2">"Bound must be a type."</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__bound__</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">def</span> <span class="nf">_get_type_vars</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tvars</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">tvars</span><span class="p">:</span>
<span class="n">tvars</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">__covariant__</span><span class="p">:</span>
<span class="n">prefix</span> <span class="o">=</span> <span class="s1">'+'</span>
<span class="k">elif</span> <span class="bp">self</span><span class="o">.</span><span class="n">__contravariant__</span><span class="p">:</span>
<span class="n">prefix</span> <span class="o">=</span> <span class="s1">'-'</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">prefix</span> <span class="o">=</span> <span class="s1">'~'</span>
<span class="k">return</span> <span class="n">prefix</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="vm">__name__</span>
<span class="k">def</span> <span class="fm">__instancecheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">instance</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Type variables cannot be used with isinstance()."</span><span class="p">)</span>
<span class="k">def</span> <span class="fm">__subclasscheck__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="bp">cls</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Type variables cannot be used with issubclass()."</span><span class="p">)</span>
<span class="c1"># Some unconstrained type variables. These are used by the container types.</span>
<span class="c1"># (These are not for export.)</span>
<span class="n">T</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'T'</span><span class="p">)</span> <span class="c1"># Any type.</span>
<span class="n">KT</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'KT'</span><span class="p">)</span> <span class="c1"># Key type.</span>
<span class="n">VT</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'VT'</span><span class="p">)</span> <span class="c1"># Value type.</span>
<span class="n">T_co</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'T_co'</span><span class="p">,</span> <span class="n">covariant</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># Any type covariant containers.</span>
<span class="n">V_co</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'V_co'</span><span class="p">,</span> <span class="n">covariant</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># Any type covariant containers.</span>
<span class="n">VT_co</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'VT_co'</span><span class="p">,</span> <span class="n">covariant</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># Value type covariant containers.</span>
<span class="n">T_contra</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'T_contra'</span><span class="p">,</span> <span class="n">contravariant</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># Ditto contravariant.</span>
<span class="c1"># A useful type variable with constraints. This represents string types.</span>
<span class="c1"># (This one *is* for export!)</span>
<span class="n">AnyStr</span> <span class="o">=</span> <span class="n">TypeVar</span><span class="p">(</span><span class="s1">'AnyStr'</span><span class="p">,</span> <span class="nb">bytes</span><span class="p">,</span> <span class="nb">str</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_replace_arg</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">tvars</span><span class="p">,</span> <span class="n">args</span><span class="p">):</span>
<span class="sd">"""An internal helper function: replace arg if it is a type variable</span>
<span class="sd"> found in tvars with corresponding substitution from args or</span>
<span class="sd"> with corresponding substitution sub-tree if arg is a generic type.</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="n">tvars</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">tvars</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="s1">'_subs_tree'</span><span class="p">)</span> <span class="ow">and</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="p">(</span><span class="n">GenericMeta</span><span class="p">,</span> <span class="n">_TypingBase</span><span class="p">)):</span>
<span class="k">return</span> <span class="n">arg</span><span class="o">.</span><span class="n">_subs_tree</span><span class="p">(</span><span class="n">tvars</span><span class="p">,</span> <span class="n">args</span><span class="p">)</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">TypeVar</span><span class="p">):</span>
<span class="k">for</span> <span class="n">i</span><span class="p">,</span> <span class="n">tvar</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">tvars</span><span class="p">):</span>
<span class="k">if</span> <span class="n">arg</span> <span class="o">==</span> <span class="n">tvar</span><span class="p">:</span>
<span class="k">return</span> <span class="n">args</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="k">return</span> <span class="n">arg</span>
<span class="c1"># Special typing constructs Union, Optional, Generic, Callable and Tuple</span>
<span class="c1"># use three special attributes for internal bookkeeping of generic types:</span>
<span class="c1"># * __parameters__ is a tuple of unique free type parameters of a generic</span>
<span class="c1"># type, for example, Dict[T, T].__parameters__ == (T,);</span>
<span class="c1"># * __origin__ keeps a reference to a type that was subscripted,</span>
<span class="c1"># e.g., Union[T, int].__origin__ == Union;</span>
<span class="c1"># * __args__ is a tuple of all arguments used in subscripting,</span>
<span class="c1"># e.g., Dict[T, int].__args__ == (T, int).</span>
<span class="k">def</span> <span class="nf">_subs_tree</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="n">tvars</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">args</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="sd">"""An internal helper function: calculate substitution tree</span>
<span class="sd"> for generic cls after replacing its type parameters with</span>
<span class="sd"> substitutions in tvars -> args (if any).</span>
<span class="sd"> Repeat the same following __origin__'s.</span>
<span class="sd"> Return a list of arguments with all possible substitutions</span>
<span class="sd"> performed. Arguments that are generic classes themselves are represented</span>
<span class="sd"> as tuples (so that no new classes are created by this function).</span>
<span class="sd"> For example: _subs_tree(List[Tuple[int, T]][str]) == [(Tuple, int, str)]</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="bp">cls</span><span class="o">.</span><span class="n">__origin__</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">return</span> <span class="bp">cls</span>
<span class="c1"># Make of chain of origins (i.e. cls -> cls.__origin__)</span>
<span class="n">current</span> <span class="o">=</span> <span class="bp">cls</span><span class="o">.</span><span class="n">__origin__</span>
<span class="n">orig_chain</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">while</span> <span class="n">current</span><span class="o">.</span><span class="n">__origin__</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">orig_chain</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">current</span><span class="p">)</span>
<span class="n">current</span> <span class="o">=</span> <span class="n">current</span><span class="o">.</span><span class="n">__origin__</span>
<span class="c1"># Replace type variables in __args__ if asked ...</span>
<span class="n">tree_args</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">arg</span> <span class="ow">in</span> <span class="bp">cls</span><span class="o">.</span><span class="n">__args__</span><span class="p">:</span>
<span class="n">tree_args</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">_replace_arg</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">tvars</span><span class="p">,</span> <span class="n">args</span><span class="p">))</span>
<span class="c1"># ... then continue replacing down the origin chain.</span>
<span class="k">for</span> <span class="n">ocls</span> <span class="ow">in</span> <span class="n">orig_chain</span><span class="p">:</span>
<span class="n">new_tree_args</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">arg</span> <span class="ow">in</span> <span class="n">ocls</span><span class="o">.</span><span class="n">__args__</span><span class="p">:</span>
<span class="n">new_tree_args</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">_replace_arg</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">ocls</span><span class="o">.</span><span class="n">__parameters__</span><span class="p">,</span> <span class="n">tree_args</span><span class="p">))</span>
<span class="n">tree_args</span> <span class="o">=</span> <span class="n">new_tree_args</span>
<span class="k">return</span> <span class="n">tree_args</span>
<span class="k">def</span> <span class="nf">_remove_dups_flatten</span><span class="p">(</span><span class="n">parameters</span><span class="p">):</span>
<span class="sd">"""An internal helper for Union creation and substitution: flatten Union's</span>
<span class="sd"> among parameters, then remove duplicates and strict subclasses.</span>
<span class="sd"> """</span>
<span class="c1"># Flatten out Union[Union[...], ...].</span>
<span class="n">params</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">p</span> <span class="ow">in</span> <span class="n">parameters</span><span class="p">:</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">p</span><span class="p">,</span> <span class="n">_Union</span><span class="p">)</span> <span class="ow">and</span> <span class="n">p</span><span class="o">.</span><span class="n">__origin__</span> <span class="ow">is</span> <span class="n">Union</span><span class="p">:</span>
<span class="n">params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">__args__</span><span class="p">)</span>
<span class="k">elif</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">p</span><span class="p">,</span> <span class="nb">tuple</span><span class="p">)</span> <span class="ow">and</span> <span class="nb">len</span><span class="p">(</span><span class="n">p</span><span class="p">)</span> <span class="o">></span> <span class="mi">0</span> <span class="ow">and</span> <span class="n">p</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="ow">is</span> <span class="n">Union</span><span class="p">:</span>
<span class="n">params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">p</span><span class="p">[</span><span class="mi">1</span><span class="p">:])</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">params</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">p</span><span class="p">)</span>
<span class="c1"># Weed out strict duplicates, preserving the first of each occurrence.</span>
<span class="n">all_params</span> <span class="o">=</span> <span class="nb">set</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">all_params</span><span class="p">)</span> <span class="o"><</span> <span class="nb">len</span><span class="p">(</span><span class="n">params</span><span class="p">):</span>
<span class="n">new_params</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">t</span> <span class="ow">in</span> <span class="n">params</span><span class="p">:</span>
<span class="k">if</span> <span class="n">t</span> <span class="ow">in</span> <span class="n">all_params</span><span class="p">:</span>