# SOME DESCRIPTIVE TITLE. # Copyright (C) 2001 Python Software Foundation # This file is distributed under the same license as the Python package. # FIRST AUTHOR , YEAR. # # Translators: # Alireza Feyzabadi Farahani, 2025 # Alireza Shabani (Revisto) , 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: 2025-07-11 14:21+0000\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" "MIME-Version: 1.0\n" "Content-Type: text/plain; charset=UTF-8\n" "Content-Transfer-Encoding: 8bit\n" "Language: fa\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" " \n" " .\n" " .\n" " .\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 "" "In the :class:`!MyClass` example, 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 with 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" " \n" " .\n" " .\n" " .\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" " \n" " .\n" " .\n" " .\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 " "for in :class:`!Base2`, and so on." msgstr "" #: ../../tutorial/classes.rst:647 msgid "" "In fact, it is slightly more complex than that; the method resolution order " "changes dynamically to support cooperative calls to :func:`super`. This " "approach is known in some other multiple-inheritance languages as call-next-" "method and is more powerful than the super call found in single-inheritance " "languages." msgstr "" #: ../../tutorial/classes.rst:653 msgid "" "Dynamic ordering is necessary because all cases of multiple inheritance " "exhibit one or more diamond relationships (where at least one of the parent " "classes can be accessed through multiple paths from the bottommost class). " "For example, all classes inherit from :class:`object`, so any case of " "multiple inheritance provides more than one path to reach :class:`object`. " "To keep the base classes from being accessed more than once, the dynamic " "algorithm linearizes the search order in a way that preserves the left-to-" "right ordering specified in each class, that calls each parent only once, " "and that is monotonic (meaning that a class can be subclassed without " "affecting the precedence order of its parents). Taken together, these " "properties make it possible to design reliable and extensible classes with " "multiple inheritance. For more detail, see :ref:`python_2.3_mro`." msgstr "" #: ../../tutorial/classes.rst:670 msgid "Private Variables" msgstr "" #: ../../tutorial/classes.rst:672 msgid "" "\"Private\" instance variables that cannot be accessed except from inside an " "object don't exist in Python. However, there is a convention that is " "followed by most Python code: a name prefixed with an underscore (e.g. " "``_spam``) should be treated as a non-public part of the API (whether it is " "a function, a method or a data member). It should be considered an " "implementation detail and subject to change without notice." msgstr "" #: ../../tutorial/classes.rst:682 msgid "" "Since there is a valid use-case for class-private members (namely to avoid " "name clashes of names with names defined by subclasses), there is limited " "support for such a mechanism, called :dfn:`name mangling`. Any identifier " "of the form ``__spam`` (at least two leading underscores, at most one " "trailing underscore) is textually replaced with ``_classname__spam``, where " "``classname`` is the current class name with leading underscore(s) " "stripped. This mangling is done without regard to the syntactic position of " "the identifier, as long as it occurs within the definition of a class." msgstr "" #: ../../tutorial/classes.rst:693 msgid "" "The :ref:`private name mangling specifications ` for " "details and special cases." msgstr "" #: ../../tutorial/classes.rst:696 msgid "" "Name mangling is helpful for letting subclasses override methods without " "breaking intraclass method calls. For example::" msgstr "" #: ../../tutorial/classes.rst:699 msgid "" "class Mapping:\n" " def __init__(self, iterable):\n" " self.items_list = []\n" " self.__update(iterable)\n" "\n" " def update(self, iterable):\n" " for item in iterable:\n" " self.items_list.append(item)\n" "\n" " __update = update # private copy of original update() method\n" "\n" "class MappingSubclass(Mapping):\n" "\n" " def update(self, keys, values):\n" " # provides new signature for update()\n" " # but does not break __init__()\n" " for item in zip(keys, values):\n" " self.items_list.append(item)" msgstr "" #: ../../tutorial/classes.rst:718 msgid "" "The above example would work even if ``MappingSubclass`` were to introduce a " "``__update`` identifier since it is replaced with ``_Mapping__update`` in " "the ``Mapping`` class and ``_MappingSubclass__update`` in the " "``MappingSubclass`` class respectively." msgstr "" #: ../../tutorial/classes.rst:723 msgid "" "Note that the mangling rules are designed mostly to avoid accidents; it " "still is possible to access or modify a variable that is considered " "private. This can even be useful in special circumstances, such as in the " "debugger." msgstr "" #: ../../tutorial/classes.rst:727 msgid "" "Notice that code passed to ``exec()`` or ``eval()`` does not consider the " "classname of the invoking class to be the current class; this is similar to " "the effect of the ``global`` statement, the effect of which is likewise " "restricted to code that is byte-compiled together. The same restriction " "applies to ``getattr()``, ``setattr()`` and ``delattr()``, as well as when " "referencing ``__dict__`` directly." msgstr "" #: ../../tutorial/classes.rst:738 msgid "Odds and Ends" msgstr "" #: ../../tutorial/classes.rst:740 msgid "" "Sometimes it is useful to have a data type similar to the Pascal \"record\" " "or C \"struct\", bundling together a few named data items. The idiomatic " "approach is to use :mod:`dataclasses` for this purpose::" msgstr "" #: ../../tutorial/classes.rst:744 msgid "" "from dataclasses import dataclass\n" "\n" "@dataclass\n" "class Employee:\n" " name: str\n" " dept: str\n" " salary: int" msgstr "" #: ../../tutorial/classes.rst:754 msgid "" ">>> john = Employee('john', 'computer lab', 1000)\n" ">>> john.dept\n" "'computer lab'\n" ">>> john.salary\n" "1000" msgstr "" #: ../../tutorial/classes.rst:760 msgid "" "A piece of Python code that expects a particular abstract data type can " "often be passed a class that emulates the methods of that data type " "instead. For instance, if you have a function that formats some data from a " "file object, you can define a class with methods :meth:`~io.TextIOBase.read` " "and :meth:`~io.TextIOBase.readline` that get the data from a string buffer " "instead, and pass it as an argument." msgstr "" #: ../../tutorial/classes.rst:772 msgid "" ":ref:`Instance method objects ` have attributes, too: :" "attr:`m.__self__ ` is the instance object with the method :" "meth:`!m`, and :attr:`m.__func__ ` is the :ref:`function " "object ` corresponding to the method." msgstr "" #: ../../tutorial/classes.rst:782 msgid "Iterators" msgstr "" #: ../../tutorial/classes.rst:784 msgid "" "By now you have probably noticed that most container objects can be looped " "over using a :keyword:`for` statement::" msgstr "" #: ../../tutorial/classes.rst:787 msgid "" "for element in [1, 2, 3]:\n" " print(element)\n" "for element in (1, 2, 3):\n" " print(element)\n" "for key in {'one':1, 'two':2}:\n" " print(key)\n" "for char in \"123\":\n" " print(char)\n" "for line in open(\"myfile.txt\"):\n" " print(line, end='')" msgstr "" #: ../../tutorial/classes.rst:798 msgid "" "This style of access is clear, concise, and convenient. The use of " "iterators pervades and unifies Python. Behind the scenes, the :keyword:" "`for` statement calls :func:`iter` on the container object. The function " "returns an iterator object that defines the method :meth:`~iterator." "__next__` which accesses elements in the container one at a time. When " "there are no more elements, :meth:`~iterator.__next__` raises a :exc:" "`StopIteration` exception which tells the :keyword:`!for` loop to " "terminate. You can call the :meth:`~iterator.__next__` method using the :" "func:`next` built-in function; this example shows how it all works::" msgstr "" #: ../../tutorial/classes.rst:807 msgid "" ">>> s = 'abc'\n" ">>> it = iter(s)\n" ">>> it\n" "\n" ">>> next(it)\n" "'a'\n" ">>> next(it)\n" "'b'\n" ">>> next(it)\n" "'c'\n" ">>> next(it)\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" " next(it)\n" "StopIteration" msgstr "" #: ../../tutorial/classes.rst:823 msgid "" "Having seen the mechanics behind the iterator protocol, it is easy to add " "iterator behavior to your classes. Define an :meth:`~container.__iter__` " "method which returns an object with a :meth:`~iterator.__next__` method. If " "the class defines :meth:`!__next__`, then :meth:`!__iter__` can just return " "``self``::" msgstr "" #: ../../tutorial/classes.rst:828 msgid "" "class Reverse:\n" " \"\"\"Iterator for looping over a sequence backwards.\"\"\"\n" " def __init__(self, data):\n" " self.data = data\n" " self.index = len(data)\n" "\n" " def __iter__(self):\n" " return self\n" "\n" " def __next__(self):\n" " if self.index == 0:\n" " raise StopIteration\n" " self.index = self.index - 1\n" " return self.data[self.index]" msgstr "" #: ../../tutorial/classes.rst:845 msgid "" ">>> rev = Reverse('spam')\n" ">>> iter(rev)\n" "<__main__.Reverse object at 0x00A1DB50>\n" ">>> for char in rev:\n" "... print(char)\n" "...\n" "m\n" "a\n" "p\n" "s" msgstr "" #: ../../tutorial/classes.rst:860 msgid "Generators" msgstr "" #: ../../tutorial/classes.rst:862 msgid "" ":term:`Generators ` are a simple and powerful tool for creating " "iterators. They are written like regular functions but use the :keyword:" "`yield` statement whenever they want to return data. Each time :func:`next` " "is called on it, the generator resumes where it left off (it remembers all " "the data values and which statement was last executed). An example shows " "that generators can be trivially easy to create::" msgstr "" ":term:`Generators ` یک ابزار ساده و قدرتمند برای ایجاد " "اینتراتورها هستند. آنها مانند توابع عادی نوشته می شوند اما هر زمان که می " "خواهند داده ای را بازگردانند از دستور :keyword:`yield` استفاده می کنند. هر " "بار که :func:`next` بر روی آن فراخوانی می شود، مولد از جایی که متوقف شده " "ادامه می یابد (تمام مقادیر داده ها و اینکه آخرین دستور اجرا شده چه بوده را " "به خاطر می آورد). یک مثال نشان می دهد که ایجاد مولدها می تواند به طرز " "باورنکردنی ساده باشد::" #: ../../tutorial/classes.rst:869 msgid "" "def reverse(data):\n" " for index in range(len(data)-1, -1, -1):\n" " yield data[index]" msgstr "" "def reverse(data):\n" " for index in range(len(data)-1, -1, -1):\n" " yield data[index]" #: ../../tutorial/classes.rst:875 msgid "" ">>> for char in reverse('golf'):\n" "... print(char)\n" "...\n" "f\n" "l\n" "o\n" "g" msgstr "" ">>> for char in reverse('golf'):\n" "... print(char)\n" "...\n" "f\n" "l\n" "o\n" "g" #: ../../tutorial/classes.rst:883 msgid "" "Anything that can be done with generators can also be done with class-based " "iterators as described in the previous section. What makes generators so " "compact is that the :meth:`~iterator.__iter__` and :meth:`~generator." "__next__` methods are created automatically." msgstr "" "هر چیزی که با تولیدکننده ها (generators) قابل انجام است، می تواند با استفاده " "از تکرارگرهای مبتنی بر کلاس نیز انجام شود، همانطور که در بخش قبلی توضیح داده " "شد. آنچه تولیدکننده ها را فشرده می کند، این است که روش های :meth:`~iterator." "__iter__` و :meth:`~generator.__next__` به طور خودکار ایجاد می شوند." #: ../../tutorial/classes.rst:888 msgid "" "Another key feature is that the local variables and execution state are " "automatically saved between calls. This made the function easier to write " "and much more clear than an approach using instance variables like ``self." "index`` and ``self.data``." msgstr "" "یکی دیگر از ویژگی های کلیدی این است که متغیرهای محلی و وضعیت اجرا به طور " "خودکار بین فراخوانی ها ذخیره می شوند. این امر نوشتن تابع را آسان تر و خیلی " "واضح تر از رویکردی که از متغیرهای نمونه ای مانند ``self.index`` و ``self." "data`` استفاده می کند، کرده است." #: ../../tutorial/classes.rst:893 msgid "" "In addition to automatic method creation and saving program state, when " "generators terminate, they automatically raise :exc:`StopIteration`. In " "combination, these features make it easy to create iterators with no more " "effort than writing a regular function." msgstr "" "علاوه بر ایجاد خودکار متدها و ذخیره سازی وضعیت برنامه، زمانی که جنراتورها " "خاتمه می یابند، به طور خودکار :exc:`StopIteration` را ایجاد می کنند. این " "ویژگی ها به صورت ترکیبی، ساختن تکرارگرها را به همان سادگی نوشتن یک تابع عادی " "امکان پذیر می سازند." #: ../../tutorial/classes.rst:902 msgid "Generator Expressions" msgstr "" #: ../../tutorial/classes.rst:904 msgid "" "Some simple generators can be coded succinctly as expressions using a syntax " "similar to list comprehensions but with parentheses instead of square " "brackets. These expressions are designed for situations where the generator " "is used right away by an enclosing function. Generator expressions are more " "compact but less versatile than full generator definitions and tend to be " "more memory friendly than equivalent list comprehensions." msgstr "" #: ../../tutorial/classes.rst:911 msgid "Examples::" msgstr "" #: ../../tutorial/classes.rst:913 msgid "" ">>> sum(i*i for i in range(10)) # sum of squares\n" "285\n" "\n" ">>> xvec = [10, 20, 30]\n" ">>> yvec = [7, 5, 3]\n" ">>> sum(x*y for x,y in zip(xvec, yvec)) # dot product\n" "260\n" "\n" ">>> unique_words = set(word for line in page for word in line.split())\n" "\n" ">>> valedictorian = max((student.gpa, student.name) for student in " "graduates)\n" "\n" ">>> data = 'golf'\n" ">>> list(data[i] for i in range(len(data)-1, -1, -1))\n" "['f', 'l', 'o', 'g']" msgstr "" #: ../../tutorial/classes.rst:932 msgid "Footnotes" msgstr "" #: ../../tutorial/classes.rst:933 msgid "" "Except for one thing. Module objects have a secret read-only attribute " "called :attr:`~object.__dict__` which returns the dictionary used to " "implement the module's namespace; the name ``__dict__`` is an attribute but " "not a global name. Obviously, using this violates the abstraction of " "namespace implementation, and should be restricted to things like post-" "mortem debuggers." msgstr "" #: ../../tutorial/classes.rst:343 msgid "object" msgstr "" #: ../../tutorial/classes.rst:343 msgid "method" msgstr "" #: ../../tutorial/classes.rst:679 msgid "name" msgstr "" #: ../../tutorial/classes.rst:679 msgid "mangling" msgstr ""