FazBrowse GitHub Viewer
|
Trending
|
URL:
|
Home
Tools:
[Download Repo ZIP]
[View Raw Code]
[Original HTTPS Page]
python-docs-fa/tutorial/classes.po at update-CI · python/python-docs-fa · GitHub
Uh oh!
There was an error while loading.
Please reload this page
.
python
/
python-docs-fa
Public
Notifications
You must be signed in to change notification settings
Fork
11
Star
51
Code
Issues
0
Pull requests
0
Actions
Projects
Security and quality
0
Insights
Additional navigation options
Code
Issues
Pull requests
Actions
Projects
Security and quality
Insights
Expand file tree
Breadcrumbs
python-docs-fa
/
tutorial
/
classes.po
Copy path
More file actions
More file actions
Latest commit
History
History
History
1413 lines (1264 loc) · 56.9 KB
Breadcrumbs
python-docs-fa
/
tutorial
/
classes.po
Copy path
File metadata and controls
1413 lines (1264 loc) · 56.9 KB
Raw
Copy raw file
Download raw file
Open symbols panel
Edit and raw actions
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
#
SOME DESCRIPTIVE TITLE.
#
Copyright (C) 2001 Python Software Foundation
#
This file is distributed under the same license as the Python package.
#
FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#
Translators:
#
Alireza Feyzabadi Farahani, 2025
#
Alireza Shabani (Revisto) <theRevisto@gmail.com>, 2025
#
AmirHossein SAMIMI, 2025
#
khosro azimi, 2025
#
#,
fuzzy
msgid ""
msgstr ""
"
Project-Id-Version
:
Python 3.14\n
"
"
Report-Msgid-Bugs-To
:
\n
"
"
POT-Creation-Date
:
2026-07-25 12:59+0330\n
"
"
PO-Revision-Date
:
2021-06-28 01:49+0000\n
"
"
Last-Translator
:
khosro azimi, 2025\n
"
"
Language-Team
:
Persian (https://app.transifex.com/python-doc/teams/5390/
"
"
fa/)\n
"
"
Language
:
fa\n
"
"
MIME-Version
:
1.0\n
"
"
Content-Type
:
text/plain; charset=UTF-8\n
"
"
Content-Transfer-Encoding
:
8bit\n
"
"
Plural-Forms
:
nplurals=2; plural=(n > 1);\n
"
#:
../../tutorial/classes.rst:5
msgid
"Classes"
msgstr
"کلاس ها"
#:
../../tutorial/classes.rst:7
msgid
""
"Classes provide a means of bundling data and functionality together. "
"Creating a new class creates a new *type* of object, allowing new "
"*instances* of that type to be made. Each class instance can have "
"attributes attached to it for maintaining its state. Class instances can "
"also have methods (defined by its class) for modifying its state."
msgstr
""
"کلاس ها وسیله ای را برای بسته بندی کردن داده و عملکرد با هم فراهم می کنند. "
"ایجاد یک کلاس جدید، نوع جدیدی ایجاد می کند که اجازه می دهد موارد جدیدی از آن "
"نوع ساخته شود. هر نمونه از کلاس می تواند صفاتی داشته باشد که به آن متصل شده "
"اند تا وضعیت آن را حفظ کنند. نمونه های کلاس می توانند همچنین متدهایی (که "
"توسط کلاس تعریف شده اند) داشته باشند تا وضعیت آن را تغییر دهند."
#:
../../tutorial/classes.rst:13
msgid
""
"Compared with other programming languages, Python's class mechanism adds "
"classes with a minimum of new syntax and semantics. It is a mixture of the "
"class mechanisms found in C++ and Modula-3. Python classes provide all the "
"standard features of Object Oriented Programming: the class inheritance "
"mechanism allows multiple base classes, a derived class can override any "
"methods of its base class or classes, and a method can call the method of a "
"base class with the same name. Objects can contain arbitrary amounts and "
"kinds of data. As is true for modules, classes partake of the dynamic "
"nature of Python: they are created at runtime, and can be modified further "
"after creation."
msgstr
""
"در مقایسه با دیگر زبان های برنامه نویسی، مکانیزم کلاس در پایتون کلاس ها را "
"با حداقل قواعد و معناشناسی جدید اضافه می کند. این مکانیزم ترکیبی از مکانیزم "
"های کلاسی است که در C++ و Modula-3 یافت می شود. کلاس های پایتون تمام ویژگی "
"های استاندارد برنامه نویسی شی گرا را فراهم می کنند: مکانیزم ارث بری کلاس ها "
"اجازه می دهد کلاس های پایه متعددی داشته باشید، یک کلاس مشتق می تواند هر یک "
"از متدهای کلاس های پایه خود را بازنویسی کند و یک متد می تواند متدی از کلاس "
"پایه با همان نام را فراخوانی کند. اشیاء می توانند حاوی مقادیر و انواع داده "
"ای دلخواه باشند. همان طور که برای ماژول ها صادق است، کلاس ها نیز از طبیعت "
"پویا در پایتون برخوردارند: آن ها در زمان اجرا ایجاد می شوند و می توانند پس "
"از ایجاد بیشتر تغییر داده شوند."
#:
../../tutorial/classes.rst:23
msgid
""
"In C++ terminology, normally class members (including the data members) are "
"*public* (except see below :ref:`tut-private`), and all member functions are "
"*virtual*. As in Modula-3, there are no shorthands for referencing the "
"object's members from its methods: the method function is declared with an "
"explicit first argument representing the object, which is provided "
"implicitly by the call. As in Smalltalk, classes themselves are objects. "
"This provides semantics for importing and renaming. Unlike C++ and "
"Modula-3, built-in types can be used as base classes for extension by the "
"user. Also, like in C++, most built-in operators with special syntax "
"(arithmetic operators, subscripting etc.) can be redefined for class "
"instances."
msgstr
""
"در اصطلاحات C++، معمولاً اعضای کلاس (از جمله اعضای داده) *public* هستند (به "
"جز موردی که در پایین :ref:`tut-private` ذکر شده است)، و تمامی توابع عضو "
"مجازی هستند. همان طور که در Modula-3، هیچ میانبرهایی برای ارجاع به اعضای "
"شیء از متدهای آن وجود ندارد: تابع متد با یک آرگومان اول صریح که نمایانگر شیء "
"است، اعلام می شود که این آرگومان به صورت ضمنی توسط فراخوانی فراهم می شود. "
"همان طور که در Smalltalk، خود کلاس ها اشیاء هستند. این ویژگی معناشناسی برای "
"وارد کردن و تغییر نام را فراهم می آورد. برخلاف C++ و Modula-3، نوع های داخلی "
"می توانند به عنوان کلاس های پایه برای توسعه توسط کاربر استفاده شوند. همچنین، "
"مانند C++، بیشتر عملگرهای داخلی با نحوی خاص (عملگرهای ریاضی، زیرنویسی و "
"غیره) می توانند برای نمونه های کلاس بازتعریف شوند."
#:
../../tutorial/classes.rst:34
msgid
""
"(Lacking universally accepted terminology to talk about classes, I will make "
"occasional use of Smalltalk and C++ terms. I would use Modula-3 terms, "
"since its object-oriented semantics are closer to those of Python than C++, "
"but I expect that few readers have heard of it.)"
msgstr
""
"(با نبود اصطلاحات پذیرفته شده جهانی برای صحبت درباره کلاسها، گاهی از "
"اصطلاحات Smalltalk و C++ استفاده خواهم کرد. من از اصطلاحات Modula-3 استفاده "
"میکردم، چون معنای شیءگرای آن به پایتون نزدیکتر از C++ است، اما انتظار دارم "
"که تعداد کمی از خوانندگان با آن آشنا باشند.)"
#:
../../tutorial/classes.rst:43
msgid
"A Word About Names and Objects"
msgstr
"سخنی درباره نامها و اشیاء"
#:
../../tutorial/classes.rst:45
msgid
""
"Objects have individuality, and multiple names (in multiple scopes) can be "
"bound to the same object. This is known as aliasing in other languages. "
"This is usually not appreciated on a first glance at Python, and can be "
"safely ignored when dealing with immutable basic types (numbers, strings, "
"tuples). However, aliasing has a possibly surprising effect on the "
"semantics of Python code involving mutable objects such as lists, "
"dictionaries, and most other types. This is usually used to the benefit of "
"the program, since aliases behave like pointers in some respects. For "
"example, passing an object is cheap since only a pointer is passed by the "
"implementation; and if a function modifies an object passed as an argument, "
"the caller will see the change --- this eliminates the need for two "
"different argument passing mechanisms as in Pascal."
msgstr
""
#:
../../tutorial/classes.rst:61
msgid
"Python Scopes and Namespaces"
msgstr
"محدوده ها و فضای نام ها در پایتون"
#:
../../tutorial/classes.rst:63
msgid
""
"Before introducing classes, I first have to tell you something about "
"Python's scope rules. Class definitions play some neat tricks with "
"namespaces, and you need to know how scopes and namespaces work to fully "
"understand what's going on. Incidentally, knowledge about this subject is "
"useful for any advanced Python programmer."
msgstr
""
"قبل از معرفی کلاس ها، ابتدا باید چیزی درباره قوانین حوزه در پایتون به شما "
"بگویم. تعریف کلاس ها چند ترفند جالب با فضاهای نام انجام می دهد و برای اینکه "
"به طور کامل متوجه شوید چه می گذرد، باید بدانید که حوزه ها و فضاهای نام چگونه "
"کار می کنند. ضمناً، آگاهی از این موضوع برای هر برنامه نویس پیشرفته پایتون "
"مفید است."
#:
../../tutorial/classes.rst:69
msgid
"Let's begin with some definitions."
msgstr
"بیایید با چند تعریف شروع کنیم."
#:
../../tutorial/classes.rst:71
msgid
""
"A *namespace* is a mapping from names to objects. Most namespaces are "
"currently implemented as Python dictionaries, but that's normally not "
"noticeable in any way (except for performance), and it may change in the "
"future. Examples of namespaces are: the set of built-in names (containing "
"functions such as :func:`abs`, and built-in exception names); the global "
"names in a module; and the local names in a function invocation. In a sense "
"the set of attributes of an object also form a namespace. The important "
"thing to know about namespaces is that there is absolutely no relation "
"between names in different namespaces; for instance, two different modules "
"may both define a function ``maximize`` without confusion --- users of the "
"modules must prefix it with the module name."
msgstr
""
"«فضای نام» *namespace* نگاشتی است از نامها به اشیا. بیشتر فضای نامها در حال "
"حاضر بهصورت دیکشنریهای پایتون پیادهسازی شدهاند، اما معمولاً این موضوع (به جز "
"در بازدهی «performance» ) قابل مشاهده نیست و ممکن است در آینده تغییر کند. "
"مثالهایی از فضای نام عبارتاند از: مجموعه نامهای داخلی (که شامل توابعی "
"مثل :func:`abs` و نامهای استثنائات داخلی است)؛ نامهای سراسری در یک ماژول؛ و "
"نامهای محلی در یک فراخوانی تابع. به نوعی، مجموعه صفات «attributes» یک شی نیز "
"یک فضای نام را تشکیل میدهد. نکته مهم درباره فضای نامها این است که هیچ "
"ارتباطی بین نامها در فضای نامهای مختلف وجود ندارد؛ برای مثال، دو ماژول مختلف "
"میتوانند هر دو تابعی با نام ``maximize`` تعریف کنند بدون اینکه ابهامی پیش "
"بیاید — استفادهکنندگان از ماژولها باید نام ماژول را به عنوان پیشوند بیاورند."
#:
../../tutorial/classes.rst:82
msgid
""
"By the way, I use the word *attribute* for any name following a dot --- for "
"example, in the expression ``z.real``, ``real`` is an attribute of the "
"object ``z``. Strictly speaking, references to names in modules are "
"attribute references: in the expression ``modname.funcname``, ``modname`` is "
"a module object and ``funcname`` is an attribute of it. In this case there "
"happens to be a straightforward mapping between the module's attributes and "
"the global names defined in the module: they share the same namespace! [#]_"
msgstr
""
"بههرحال، من واژهٔ *ویژگی* «*attribute*» را برای هر نامی که بعد از یک نقطه "
"بیاید به کار میبرم — برای مثال، در عبارت ``z.real``, ``real`` یک ویژگیِ شیءِ "
"``z`` است. از نظر دقیقتر، ارجاع به نامها در ماژولها نیز نوعی ارجاع به ویژگی "
"محسوب میشود: در عبارت ``modname.funcname``, ``modname`` یک شیءِ ماژول است و "
"``funcname`` یکی از ویژگیهای آن است. در این حالت، نگاشتی ساده و مستقیم بین "
"ویژگیهای ماژول و نامهای سراسری تعریفشده در آن وجود دارد: هر دو یک فضای نام "
"(namespace) را به اشتراک میگذارند! [#]_"
#:
../../tutorial/classes.rst:90
msgid
""
"Attributes may be read-only or writable. In the latter case, assignment to "
"attributes is possible. Module attributes are writable: you can write "
"``modname.the_answer = 42``. Writable attributes may also be deleted with "
"the :keyword:`del` statement. For example, ``del modname.the_answer`` will "
"remove the attribute :attr:`!the_answer` from the object named by "
"``modname``."
msgstr
""
"ویژگی ها ممکن است فقط خواندنی یا قابل نوشتن باشند. در حالت دوم، اختصاص دادن "
"به ویژگی ها ممکن است. ویژگی های ماژول قابل نوشتن هستند: می توانید "
"``modname.the_answer = 42`` را بنویسید. ویژگی های قابل نوشتن را می توان با "
"دستور :keyword:`del` نیز حذف کرد. به عنوان مثال، ``del modname.the_answer`` "
"ویژگی :attr:`!the_answer` را از شیئی که توسط ``modname`` نامگذاری شده است "
"حذف خواهد کرد."
#:
../../tutorial/classes.rst:96
msgid
""
"Namespaces are created at different moments and have different lifetimes. "
"The namespace containing the built-in names is created when the Python "
"interpreter starts up, and is never deleted. The global namespace for a "
"module is created when the module definition is read in; normally, module "
"namespaces also last until the interpreter quits. The statements executed "
"by the top-level invocation of the interpreter, either read from a script "
"file or interactively, are considered part of a module "
"called :mod:`__main__`, so they have their own global namespace. (The built-"
"in names actually also live in a module; this is called :mod:`builtins`.)"
msgstr
""
"فضاهای نام در لحظات مختلف ایجاد می شوند و دارای طول عمرهای متفاوتی هستند. "
"فضای نام که شامل نام های داخلی است، زمانی که مفسر پایتون شروع به کار می کند "
"ایجاد می شود و هرگز حذف نمی شود. فضای نام عمومی برای یک ماژول زمانی که تعریف "
"ماژول خوانده می شود ایجاد می گردد؛ به طور معمول، فضاهای نام ماژول نیز تا "
"زمانی که مفسر پایان یابد باقی می مانند. دستوراتی که توسط اجرای سطح بالای "
"مفسر، یا از فایل اسکریپت خوانده شده یا به طور تعاملی اجرا می شوند، به عنوان "
"بخشی از ماژولی به نام :mod:`__main__` در نظر گرفته می شوند، بنابراین آن ها "
"فضای نام عمومی خود را دارند. (نامهای درونساخت نیز در واقع در یک ماژول قرار "
"دارند؛ این ماژول :mod:`builtins` نامیده می شود.)"
#:
../../tutorial/classes.rst:106
msgid
""
"The local namespace for a function is created when the function is called, "
"and deleted when the function returns or raises an exception that is not "
"handled within the function. (Actually, forgetting would be a better way to "
"describe what actually happens.) Of course, recursive invocations each have "
"their own local namespace."
msgstr
""
"فضای نام محلی برای یک تابع زمانی ایجاد میشود که تابع فراخوانی شود و زمانی که "
"تابع بازمیگردد یا استثنایی پرتاب میکند که در درون تابع مدیریت نمیشود، حذف "
"میگردد. (در واقع، «فراموش شدن» توصیف بهتری برای چیزی است که واقعاً اتفاق "
"میافتد.) البته، هر فراخوانی بازگشتی، فضای نام محلی خودش را دارد."
#:
../../tutorial/classes.rst:112
msgid
""
"A *scope* is a textual region of a Python program where a namespace is "
"directly accessible.
\"
Directly accessible
\"
here means that an unqualified "
"reference to a name attempts to find the name in the namespace."
msgstr
""
"یک *دامنه* «*scope*» یک ناحیه متنی از یک برنامه پایتون است که در آن یک فضای "
"نام «namespace» به طور مستقیم قابل دستیابی است.
\"
به طور مستقیم قابل "
"دستیابی
\"
در اینجا به این معنی است که یک ارجاع بدون صلاحیت به یک نام تلاش می "
"کند تا نام «name» را در فضای نام «namespace» پیدا کند."
#:
../../tutorial/classes.rst:116
msgid
""
"Although scopes are determined statically, they are used dynamically. At any "
"time during execution, there are 3 or 4 nested scopes whose namespaces are "
"directly accessible:"
msgstr
""
#:
../../tutorial/classes.rst:120
msgid
"the innermost scope, which is searched first, contains the local names"
msgstr
"درونی ترین حوزه، که ابتدا جستجو می شود، شامل نام های محلی است"
#:
../../tutorial/classes.rst:121
msgid
""
"the scopes of any enclosing functions, which are searched starting with the "
"nearest enclosing scope, contain non-local, but also non-global names"
msgstr
""
#:
../../tutorial/classes.rst:123
msgid
"the next-to-last scope contains the current module's global names"
msgstr
"حوزه قبل از آخر شامل نام های عمومی ماژول جاری است."
#:
../../tutorial/classes.rst:124
msgid
""
"the outermost scope (searched last) is the namespace containing built-in "
"names"
msgstr
""
#:
../../tutorial/classes.rst:126
msgid
""
"If a name is declared global, then all references and assignments go "
"directly to the next-to-last scope containing the module's global names. To "
"rebind variables found outside of the innermost scope, "
"the :keyword:`nonlocal` statement can be used; if not declared nonlocal, "
"those variables are read-only (an attempt to write to such a variable will "
"simply create a *new* local variable in the innermost scope, leaving the "
"identically named outer variable unchanged)."
msgstr
""
#:
../../tutorial/classes.rst:133
msgid
""
"Usually, the local scope references the local names of the (textually) "
"current function. Outside functions, the local scope references the same "
"namespace as the global scope: the module's namespace. Class definitions "
"place yet another namespace in the local scope."
msgstr
""
#:
../../tutorial/classes.rst:138
msgid
""
"It is important to realize that scopes are determined textually: the global "
"scope of a function defined in a module is that module's namespace, no "
"matter from where or by what alias the function is called. On the other "
"hand, the actual search for names is done dynamically, at run time --- "
"however, the language definition is evolving towards static name resolution, "
"at
\"
compile
\"
time, so don't rely on dynamic name resolution! (In fact, "
"local variables are already determined statically.)"
msgstr
""
#:
../../tutorial/classes.rst:146
msgid
""
"A special quirk of Python is that -- if no :keyword:`global` "
"or :keyword:`nonlocal` statement is in effect -- assignments to names always "
"go into the innermost scope. Assignments do not copy data --- they just bind "
"names to objects. The same is true for deletions: the statement ``del x`` "
"removes the binding of ``x`` from the namespace referenced by the local "
"scope. In fact, all operations that introduce new names use the local "
"scope: in particular, :keyword:`import` statements and function definitions "
"bind the module or function name in the local scope."
msgstr
""
#:
../../tutorial/classes.rst:154
msgid
""
"The :keyword:`global` statement can be used to indicate that particular "
"variables live in the global scope and should be rebound there; "
"the :keyword:`nonlocal` statement indicates that particular variables live "
"in an enclosing scope and should be rebound there."
msgstr
""
#:
../../tutorial/classes.rst:162
msgid
"Scopes and Namespaces Example"
msgstr
""
#:
../../tutorial/classes.rst:164
msgid
""
"This is an example demonstrating how to reference the different scopes and "
"namespaces, and how :keyword:`global` and :keyword:`nonlocal` affect "
"variable binding::"
msgstr
""
#:
../../tutorial/classes.rst:168
msgid
""
"def scope_test():\n"
" def do_local():\n"
" spam =
\"
local spam
\"
\n"
"\n"
" def do_nonlocal():\n"
" nonlocal spam\n"
" spam =
\"
nonlocal spam
\"
\n"
"\n"
" def do_global():\n"
" global spam\n"
" spam =
\"
global spam
\"
\n"
"\n"
" spam =
\"
test spam
\"
\n"
" do_local()\n"
" print(
\"
After local assignment:
\"
, spam)\n"
" do_nonlocal()\n"
" print(
\"
After nonlocal assignment:
\"
, spam)\n"
" do_global()\n"
" print(
\"
After global assignment:
\"
, spam)\n"
"\n"
"scope_test()\n"
"print(
\"
In global scope:
\"
, spam)"
msgstr
""
#:
../../tutorial/classes.rst:191
msgid
"The output of the example code is:"
msgstr
""
#:
../../tutorial/classes.rst:193
msgid
""
"After local assignment: test spam\n"
"After nonlocal assignment: nonlocal spam\n"
"After global assignment: nonlocal spam\n"
"In global scope: global spam"
msgstr
""
#:
../../tutorial/classes.rst:200
msgid
""
"Note how the *local* assignment (which is default) didn't change "
"*scope_test*
\\
's binding of *spam*. The :keyword:`nonlocal` assignment "
"changed *scope_test*
\\
's binding of *spam*, and the :keyword:`global` "
"assignment changed the module-level binding."
msgstr
""
#:
../../tutorial/classes.rst:205
msgid
""
"You can also see that there was no previous binding for *spam* before "
"the :keyword:`global` assignment."
msgstr
""
#:
../../tutorial/classes.rst:212
msgid
"A First Look at Classes"
msgstr
"در نگاه اول به کلاس ها"
#:
../../tutorial/classes.rst:214
msgid
""
"Classes introduce a little bit of new syntax, three new object types, and "
"some new semantics."
msgstr
""
"کلاس ها اندکی سینتکس جدید، سه نوع شئ جدید و برخی مفاهیم معنایی جدید معرفی می "
"کنند."
#:
../../tutorial/classes.rst:221
msgid
"Class Definition Syntax"
msgstr
"قواعد تعریف کلاس"
#:
../../tutorial/classes.rst:223
msgid
"The simplest form of class definition looks like this::"
msgstr
"ساده ترین شکل تعریف کلاس به این صورت است:"
#:
../../tutorial/classes.rst:225
msgid
""
"class ClassName:\n"
" <statement-1>\n"
" .\n"
" .\n"
" .\n"
" <statement-N>"
msgstr
""
#:
../../tutorial/classes.rst:232
msgid
""
"Class definitions, like function definitions (:keyword:`def` statements) "
"must be executed before they have any effect. (You could conceivably place "
"a class definition in a branch of an :keyword:`if` statement, or inside a "
"function.)"
msgstr
""
#:
../../tutorial/classes.rst:236
msgid
""
"In practice, the statements inside a class definition will usually be "
"function definitions, but other statements are allowed, and sometimes useful "
"--- we'll come back to this later. The function definitions inside a class "
"normally have a peculiar form of argument list, dictated by the calling "
"conventions for methods --- again, this is explained later."
msgstr
""
#:
../../tutorial/classes.rst:242
msgid
""
"When a class definition is entered, a new namespace is created, and used as "
"the local scope --- thus, all assignments to local variables go into this "
"new namespace. In particular, function definitions bind the name of the new "
"function here."
msgstr
""
#:
../../tutorial/classes.rst:247
msgid
""
"When a class definition is left normally (via the end), a *class object* is "
"created. This is basically a wrapper around the contents of the namespace "
"created by the class definition; we'll learn more about class objects in the "
"next section. The original local scope (the one in effect just before the "
"class definition was entered) is reinstated, and the class object is bound "
"here to the class name given in the class definition header (:class:`!"
"ClassName` in the example)."
msgstr
""
#:
../../tutorial/classes.rst:259
msgid
"Class Objects"
msgstr
""
#:
../../tutorial/classes.rst:261
msgid
""
"Class objects support two kinds of operations: attribute references and "
"instantiation."
msgstr
""
#:
../../tutorial/classes.rst:264
msgid
""
"*Attribute references* use the standard syntax used for all attribute "
"references in Python: ``obj.name``. Valid attribute names are all the names "
"that were in the class's namespace when the class object was created. So, "
"if the class definition looked like this::"
msgstr
""
#:
../../tutorial/classes.rst:269
msgid
""
"class MyClass:\n"
"
\"\"\"
A simple example class
\"\"\"
\n"
" i = 12345\n"
"\n"
" def f(self):\n"
" return 'hello world'"
msgstr
""
#:
../../tutorial/classes.rst:276
msgid
""
"then ``MyClass.i`` and ``MyClass.f`` are valid attribute references, "
"returning an integer and a function object, respectively. Class attributes "
"can also be assigned to, so you can change the value of ``MyClass.i`` by "
"assignment. :attr:`~type.__doc__` is also a valid attribute, returning the "
"docstring belonging to the class: ``
\"
A simple example class
\"
``."
msgstr
""
#:
../../tutorial/classes.rst:282
msgid
""
"Class *instantiation* uses function notation. Just pretend that the class "
"object is a parameterless function that returns a new instance of the class. "
"For example (assuming the above class)::"
msgstr
""
#:
../../tutorial/classes.rst:286
../../tutorial/classes.rst:303
msgid
"x = MyClass()"
msgstr
""
#:
../../tutorial/classes.rst:288
msgid
""
"creates a new *instance* of the class and assigns this object to the local "
"variable ``x``."
msgstr
""
#:
../../tutorial/classes.rst:291
msgid
""
"The instantiation operation (
\"
calling
\"
a class object) creates an empty "
"object. Many classes like to create objects with instances customized to a "
"specific initial state. Therefore a class may define a special method "
"named :meth:`~object.__init__`, like this::"
msgstr
""
#:
../../tutorial/classes.rst:296
msgid
""
"def __init__(self):\n"
" self.data = []"
msgstr
""
#:
../../tutorial/classes.rst:299
msgid
""
"When a class defines an :meth:`~object.__init__` method, class instantiation "
"automatically invokes :meth:`!__init__` for the newly created class "
"instance. So in this example, a new, initialized instance can be obtained "
"by::"
msgstr
""
#:
../../tutorial/classes.rst:305
msgid
""
"Of course, the :meth:`~object.__init__` method may have arguments for "
"greater flexibility. In that case, arguments given to the class "
"instantiation operator are passed on to :meth:`!__init__`. For example, ::"
msgstr
""
#:
../../tutorial/classes.rst:309
msgid
""
">>> class Complex:\n"
"... def __init__(self, realpart, imagpart):\n"
"... self.r = realpart\n"
"... self.i = imagpart\n"
"...\n"
">>> x = Complex(3.0, -4.5)\n"
">>> x.r, x.i\n"
"(3.0, -4.5)"
msgstr
""
#:
../../tutorial/classes.rst:322
msgid
"Instance Objects"
msgstr
""
#:
../../tutorial/classes.rst:324
msgid
""
"Now what can we do with instance objects? The only operations understood by "
"instance objects are attribute references. There are two kinds of valid "
"attribute names: data attributes and methods."
msgstr
""
#:
../../tutorial/classes.rst:328
msgid
""
"*Data attributes* correspond to
\"
instance variables
\"
in Smalltalk, and to "
"
\"
data members
\"
in C++. Data attributes need not be declared; like local "
"variables, they spring into existence when they are first assigned to. For "
"example, if ``x`` is the instance of :class:`!MyClass` created above, the "
"following piece of code will print the value ``16``, without leaving a "
"trace::"
msgstr
""
#:
../../tutorial/classes.rst:334
msgid
""
"x.counter = 1\n"
"while x.counter < 10:\n"
" x.counter = x.counter * 2\n"
"print(x.counter)\n"
"del x.counter"
msgstr
""
#:
../../tutorial/classes.rst:340
msgid
""
"The other kind of instance attribute reference is a *method*. A method is a "
"function that
\"
belongs to
\"
an object."
msgstr
""
#:
../../tutorial/classes.rst:345
msgid
""
"Valid method names of an instance object depend on its class. By "
"definition, all attributes of a class that are function objects define "
"corresponding methods of its instances. So in our example, ``x.f`` is a "
"valid method reference, since ``MyClass.f`` is a function, but ``x.i`` is "
"not, since ``MyClass.i`` is not. But ``x.f`` is not the same thing as "
"``MyClass.f`` --- it is a *method object*, not a function object."
msgstr
""
#:
../../tutorial/classes.rst:356
msgid
"Method Objects"
msgstr
""
#:
../../tutorial/classes.rst:358
msgid
"Usually, a method is called right after it is bound::"
msgstr
""
#:
../../tutorial/classes.rst:360
msgid
"x.f()"
msgstr
""
#:
../../tutorial/classes.rst:362
msgid
""
"If ``x = MyClass()``, as above, this will return the string ``'hello "
"world'``. However, it is not necessary to call a method right away: ``x.f`` "
"is a method object, and can be stored away and called at a later time. For "
"example::"
msgstr
""
#:
../../tutorial/classes.rst:366
msgid
""
"xf = x.f\n"
"while True:\n"
" print(xf())"
msgstr
""
#:
../../tutorial/classes.rst:370
msgid
"will continue to print ``hello world`` until the end of time."
msgstr
""
#:
../../tutorial/classes.rst:372
msgid
""
"What exactly happens when a method is called? You may have noticed that "
"``x.f()`` was called without an argument above, even though the function "
"definition for :meth:`!f` specified an argument. What happened to the "
"argument? Surely Python raises an exception when a function that requires an "
"argument is called without any --- even if the argument isn't actually "
"used..."
msgstr
""
#:
../../tutorial/classes.rst:378
msgid
""
"Actually, you may have guessed the answer: the special thing about methods "
"is that the instance object is passed as the first argument of the "
"function. In our example, the call ``x.f()`` is exactly equivalent to "
"``MyClass.f(x)``. In general, calling a method with a list of *n* arguments "
"is equivalent to calling the corresponding function with an argument list "
"that is created by inserting the method's instance object before the first "
"argument."
msgstr
""
#:
../../tutorial/classes.rst:385
msgid
""
"In general, methods work as follows. When a non-data attribute of an "
"instance is referenced, the instance's class is searched. If the name "
"denotes a valid class attribute that is a function object, references to "
"both the instance object and the function object are packed into a method "
"object. When the method object is called with an argument list, a new "
"argument list is constructed from the instance object and the argument list, "
"and the function object is called with this new argument list."
msgstr
""
#:
../../tutorial/classes.rst:398
msgid
"Class and Instance Variables"
msgstr
""
#:
../../tutorial/classes.rst:400
msgid
""
"Generally speaking, instance variables are for data unique to each instance "
"and class variables are for attributes and methods shared by all instances "
"of the class::"
msgstr
""
#:
../../tutorial/classes.rst:404
msgid
""
"class Dog:\n"
"\n"
" kind = 'canine' # class variable shared by all instances\n"
"\n"
" def __init__(self, name):\n"
" self.name = name # instance variable unique to each instance\n"
"\n"
">>> d = Dog('Fido')\n"
">>> e = Dog('Buddy')\n"
">>> d.kind # shared by all dogs\n"
"'canine'\n"
">>> e.kind # shared by all dogs\n"
"'canine'\n"
">>> d.name # unique to d\n"
"'Fido'\n"
">>> e.name # unique to e\n"
"'Buddy'"
msgstr
""
#:
../../tutorial/classes.rst:422
msgid
""
"As discussed in :ref:`tut-object`, shared data can have possibly surprising "
"effects involving :term:`mutable` objects such as lists and dictionaries. "
"For example, the *tricks* list in the following code should not be used as a "
"class variable because just a single list would be shared by all *Dog* "
"instances::"
msgstr
""
#:
../../tutorial/classes.rst:428
msgid
""
"class Dog:\n"
"\n"
" tricks = [] # mistaken use of a class variable\n"
"\n"
" def __init__(self, name):\n"
" self.name = name\n"
"\n"
" def add_trick(self, trick):\n"
" self.tricks.append(trick)\n"
"\n"
">>> d = Dog('Fido')\n"
">>> e = Dog('Buddy')\n"
">>> d.add_trick('roll over')\n"
">>> e.add_trick('play dead')\n"
">>> d.tricks # unexpectedly shared by all dogs\n"
"['roll over', 'play dead']"
msgstr
""
#:
../../tutorial/classes.rst:445
msgid
"Correct design of the class should use an instance variable instead::"
msgstr
""
#:
../../tutorial/classes.rst:447
msgid
""
"class Dog:\n"
"\n"
" def __init__(self, name):\n"
" self.name = name\n"
" self.tricks = [] # creates a new empty list for each dog\n"
"\n"
" def add_trick(self, trick):\n"
" self.tricks.append(trick)\n"
"\n"
">>> d = Dog('Fido')\n"
">>> e = Dog('Buddy')\n"
">>> d.add_trick('roll over')\n"
">>> e.add_trick('play dead')\n"
">>> d.tricks\n"
"['roll over']\n"
">>> e.tricks\n"
"['play dead']"
msgstr
""
#:
../../tutorial/classes.rst:469
msgid
"Random Remarks"
msgstr
""
#:
../../tutorial/classes.rst:473
msgid
""
"If the same attribute name occurs in both an instance and in a class, then "
"attribute lookup prioritizes the instance::"
msgstr
""
#:
../../tutorial/classes.rst:476
msgid
""
">>> class Warehouse:\n"
"... purpose = 'storage'\n"
"... region = 'west'\n"
"...\n"
">>> w1 = Warehouse()\n"
">>> print(w1.purpose, w1.region)\n"
"storage west\n"
">>> w2 = Warehouse()\n"
">>> w2.region = 'east'\n"
">>> print(w2.purpose, w2.region)\n"
"storage east"
msgstr
""
#:
../../tutorial/classes.rst:488
msgid
""
"Data attributes may be referenced by methods as well as by ordinary users "
"(
\"
clients
\"
) of an object. In other words, classes are not usable to "
"implement pure abstract data types. In fact, nothing in Python makes it "
"possible to enforce data hiding --- it is all based upon convention. (On "
"the other hand, the Python implementation, written in C, can completely hide "
"implementation details and control access to an object if necessary; this "
"can be used by extensions to Python written in C.)"
msgstr
""
#:
../../tutorial/classes.rst:496
msgid
""
"Clients should use data attributes with care --- clients may mess up "
"invariants maintained by the methods by stamping on their data attributes. "
"Note that clients may add data attributes of their own to an instance object "
"without affecting the validity of the methods, as long as name conflicts are "
"avoided --- again, a naming convention can save a lot of headaches here."
msgstr
""
#:
../../tutorial/classes.rst:502
msgid
""
"There is no shorthand for referencing data attributes (or other methods!) "
"from within methods. I find that this actually increases the readability of "
"methods: there is no chance of confusing local variables and instance "
"variables when glancing through a method."
msgstr
""
#:
../../tutorial/classes.rst:507
msgid
""
"Often, the first argument of a method is called ``self``. This is nothing "
"more than a convention: the name ``self`` has absolutely no special meaning "
"to Python. Note, however, that by not following the convention your code "
"may be less readable to other Python programmers, and it is also conceivable "
"that a *class browser* program might be written that relies upon such a "
"convention."
msgstr
""
#:
../../tutorial/classes.rst:513
msgid
""
"Any function object that is a class attribute defines a method for instances "
"of that class. It is not necessary that the function definition is "
"textually enclosed in the class definition: assigning a function object to a "
"local variable in the class is also ok. For example::"
msgstr
""
#:
../../tutorial/classes.rst:518
msgid
""
"# Function defined outside the class\n"
"def f1(self, x, y):\n"
" return min(x, x+y)\n"
"\n"
"class C:\n"
" f = f1\n"
"\n"
" def g(self):\n"
" return 'hello world'\n"
"\n"
" h = g"
msgstr
""
#:
../../tutorial/classes.rst:530
msgid
""
"Now ``f``, ``g`` and ``h`` are all attributes of class :class:`!C` that "
"refer to function objects, and consequently they are all methods of "
"instances of :class:`!C` --- ``h`` being exactly equivalent to ``g``. Note "
"that this practice usually only serves to confuse the reader of a program."
msgstr
""
#:
../../tutorial/classes.rst:535
msgid
""
"Methods may call other methods by using method attributes of the ``self`` "
"argument::"
msgstr
""
#:
../../tutorial/classes.rst:538
msgid
""
"class Bag:\n"
" def __init__(self):\n"
" self.data = []\n"
"\n"
" def add(self, x):\n"
" self.data.append(x)\n"
"\n"
" def addtwice(self, x):\n"
" self.add(x)\n"
" self.add(x)"
msgstr
""
#:
../../tutorial/classes.rst:549
msgid
""
"Methods may reference global names in the same way as ordinary functions. "
"The global scope associated with a method is the module containing its "
"definition. (A class is never used as a global scope.) While one rarely "
"encounters a good reason for using global data in a method, there are many "
"legitimate uses of the global scope: for one thing, functions and modules "
"imported into the global scope can be used by methods, as well as functions "
"and classes defined in it. Usually, the class containing the method is "
"itself defined in this global scope, and in the next section we'll find some "
"good reasons why a method would want to reference its own class."
msgstr
""
#:
../../tutorial/classes.rst:559
msgid
""
"Each value is an object, and therefore has a *class* (also called its "
"*type*). It is stored as ``object.__class__``."
msgstr
""
#:
../../tutorial/classes.rst:566
msgid
"Inheritance"
msgstr
""
#:
../../tutorial/classes.rst:568
msgid
""
"Of course, a language feature would not be worthy of the name
\"
class
\"
"
"without supporting inheritance. The syntax for a derived class definition "
"looks like this::"
msgstr
""
#:
../../tutorial/classes.rst:572
msgid
""
"class DerivedClassName(BaseClassName):\n"
" <statement-1>\n"
" .\n"
" .\n"
" .\n"
" <statement-N>"
msgstr
""
#:
../../tutorial/classes.rst:579
msgid
""
"The name :class:`!BaseClassName` must be defined in a namespace accessible "
"from the scope containing the derived class definition. In place of a base "
"class name, other arbitrary expressions are also allowed. This can be "
"useful, for example, when the base class is defined in another module::"
msgstr
""
#:
../../tutorial/classes.rst:585
msgid
"class DerivedClassName(modname.BaseClassName):"
msgstr
""
#:
../../tutorial/classes.rst:587
msgid
""
"Execution of a derived class definition proceeds the same as for a base "
"class. When the class object is constructed, the base class is remembered. "
"This is used for resolving attribute references: if a requested attribute is "
"not found in the class, the search proceeds to look in the base class. This "
"rule is applied recursively if the base class itself is derived from some "
"other class."
msgstr
""
#:
../../tutorial/classes.rst:593
msgid
""
"There's nothing special about instantiation of derived classes: "
"``DerivedClassName()`` creates a new instance of the class. Method "
"references are resolved as follows: the corresponding class attribute is "
"searched, descending down the chain of base classes if necessary, and the "
"method reference is valid if this yields a function object."
msgstr
""
#:
../../tutorial/classes.rst:599
msgid
""
"Derived classes may override methods of their base classes. Because methods "
"have no special privileges when calling other methods of the same object, a "
"method of a base class that calls another method defined in the same base "
"class may end up calling a method of a derived class that overrides it. "
"(For C++ programmers: all methods in Python are effectively ``virtual``.)"
msgstr
""
#:
../../tutorial/classes.rst:605
msgid
""
"An overriding method in a derived class may in fact want to extend rather "
"than simply replace the base class method of the same name. There is a "
"simple way to call the base class method directly: just call "
"``BaseClassName.methodname(self, arguments)``. This is occasionally useful "
"to clients as well. (Note that this only works if the base class is "
"accessible as ``BaseClassName`` in the global scope.)"
msgstr
""
#:
../../tutorial/classes.rst:612
msgid
"Python has two built-in functions that work with inheritance:"
msgstr
""
#:
../../tutorial/classes.rst:614
msgid
""
"Use :func:`isinstance` to check an instance's type: ``isinstance(obj, int)`` "
"will be ``True`` only if ``obj.__class__`` is :class:`int` or some class "
"derived from :class:`int`."
msgstr
""
#:
../../tutorial/classes.rst:618
msgid
""
"Use :func:`issubclass` to check class inheritance: ``issubclass(bool, int)`` "
"is ``True`` since :class:`bool` is a subclass of :class:`int`. However, "
"``issubclass(float, int)`` is ``False`` since :class:`float` is not a "
"subclass of :class:`int`."
msgstr
""
#:
../../tutorial/classes.rst:628
msgid
"Multiple Inheritance"
msgstr
""
#:
../../tutorial/classes.rst:630
msgid
""
"Python supports a form of multiple inheritance as well. A class definition "
"with multiple base classes looks like this::"
msgstr
""
#:
../../tutorial/classes.rst:633
msgid
""
"class DerivedClassName(Base1, Base2, Base3):\n"
" <statement-1>\n"
" .\n"
" .\n"
" .\n"
" <statement-N>"
msgstr
""
#:
../../tutorial/classes.rst:640
msgid
""
"For most purposes, in the simplest cases, you can think of the search for "
"attributes inherited from a parent class as depth-first, left-to-right, not "
"searching twice in the same class where there is an overlap in the "
"hierarchy. Thus, if an attribute is not found in :class:`!DerivedClassName`, "
"it is searched for in :class:`!Base1`, then (recursively) in the base "
"classes of :class:`!Base1`, and if it was not found there, it was searched "
View remainder of file in raw view
Back
|
FazBrowse Home
|
New Git URL