# 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 Shabani (Revisto) , 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 01:50+0000\n" "Last-Translator: Alireza Shabani (Revisto) , 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/controlflow.rst:5 msgid "More Control Flow Tools" msgstr "" #: ../../tutorial/controlflow.rst:7 msgid "" "As well as the :keyword:`while` statement just introduced, Python uses a few " "more that we will encounter in this chapter." msgstr "" #: ../../tutorial/controlflow.rst:14 msgid ":keyword:`!if` Statements" msgstr "" #: ../../tutorial/controlflow.rst:16 msgid "" "Perhaps the most well-known statement type is the :keyword:`if` statement. " "For example::" msgstr "" #: ../../tutorial/controlflow.rst:19 msgid "" ">>> x = int(input(\"Please enter an integer: \"))\n" "Please enter an integer: 42\n" ">>> if x < 0:\n" "... x = 0\n" "... print('Negative changed to zero')\n" "... elif x == 0:\n" "... print('Zero')\n" "... elif x == 1:\n" "... print('Single')\n" "... else:\n" "... print('More')\n" "...\n" "More" msgstr "" #: ../../tutorial/controlflow.rst:33 msgid "" "There can be zero or more :keyword:`elif` parts, and the :keyword:`else` " "part is optional. The keyword ':keyword:`!elif`' is short for 'else if', " "and is useful to avoid excessive indentation. An :keyword:`!" "if` ... :keyword:`!elif` ... :keyword:`!elif` ... sequence is a substitute " "for the ``switch`` or ``case`` statements found in other languages." msgstr "" #: ../../tutorial/controlflow.rst:39 msgid "" "If you're comparing the same value to several constants, or checking for " "specific types or attributes, you may also find the :keyword:`!match` " "statement useful. For more details see :ref:`tut-match`." msgstr "" #: ../../tutorial/controlflow.rst:46 msgid ":keyword:`!for` Statements" msgstr "" #: ../../tutorial/controlflow.rst:51 msgid "" "The :keyword:`for` statement in Python differs a bit from what you may be " "used to in C or Pascal. Rather than always iterating over an arithmetic " "progression of numbers (like in Pascal), or giving the user the ability to " "define both the iteration step and halting condition (as C), " "Python's :keyword:`!for` statement iterates over the items of any sequence " "(a list or a string), in the order that they appear in the sequence. For " "example (no pun intended):" msgstr "" #: ../../tutorial/controlflow.rst:63 msgid "" ">>> # Measure some strings:\n" ">>> words = ['cat', 'window', 'defenestrate']\n" ">>> for w in words:\n" "... print(w, len(w))\n" "...\n" "cat 3\n" "window 6\n" "defenestrate 12" msgstr "" #: ../../tutorial/controlflow.rst:72 msgid "" "Code that modifies a collection while iterating over that same collection " "can be tricky to get right. Instead, it is usually more straight-forward to " "loop over a copy of the collection or to create a new collection::" msgstr "" #: ../../tutorial/controlflow.rst:76 msgid "" "# Create a sample collection\n" "users = {'Hans': 'active', 'Éléonore': 'inactive', '景太郎': 'active'}\n" "\n" "# Strategy: Iterate over a copy\n" "for user, status in users.copy().items():\n" " if status == 'inactive':\n" " del users[user]\n" "\n" "# Strategy: Create a new collection\n" "active_users = {}\n" "for user, status in users.items():\n" " if status == 'active':\n" " active_users[user] = status" msgstr "" #: ../../tutorial/controlflow.rst:94 msgid "The :func:`range` Function" msgstr "" #: ../../tutorial/controlflow.rst:96 msgid "" "If you do need to iterate over a sequence of numbers, the built-in " "function :func:`range` comes in handy. It generates arithmetic " "progressions::" msgstr "" #: ../../tutorial/controlflow.rst:99 msgid "" ">>> for i in range(5):\n" "... print(i)\n" "...\n" "0\n" "1\n" "2\n" "3\n" "4" msgstr "" #: ../../tutorial/controlflow.rst:108 msgid "" "The given end point is never part of the generated sequence; ``range(10)`` " "generates 10 values, the legal indices for items of a sequence of length " "10. It is possible to let the range start at another number, or to specify " "a different increment (even negative; sometimes this is called the 'step')::" msgstr "" #: ../../tutorial/controlflow.rst:113 msgid "" ">>> list(range(5, 10))\n" "[5, 6, 7, 8, 9]\n" "\n" ">>> list(range(0, 10, 3))\n" "[0, 3, 6, 9]\n" "\n" ">>> list(range(-10, -100, -30))\n" "[-10, -40, -70]" msgstr "" #: ../../tutorial/controlflow.rst:122 msgid "" "To iterate over the indices of a sequence, you can combine :func:`range` " "and :func:`len` as follows::" msgstr "" #: ../../tutorial/controlflow.rst:125 msgid "" ">>> a = ['Mary', 'had', 'a', 'little', 'lamb']\n" ">>> for i in range(len(a)):\n" "... print(i, a[i])\n" "...\n" "0 Mary\n" "1 had\n" "2 a\n" "3 little\n" "4 lamb" msgstr "" #: ../../tutorial/controlflow.rst:135 msgid "" "In most such cases, however, it is convenient to use the :func:`enumerate` " "function, see :ref:`tut-loopidioms`." msgstr "" #: ../../tutorial/controlflow.rst:138 msgid "A strange thing happens if you just print a range::" msgstr "" #: ../../tutorial/controlflow.rst:140 msgid "" ">>> range(10)\n" "range(0, 10)" msgstr "" #: ../../tutorial/controlflow.rst:143 msgid "" "In many ways the object returned by :func:`range` behaves as if it is a " "list, but in fact it isn't. It is an object which returns the successive " "items of the desired sequence when you iterate over it, but it doesn't " "really make the list, thus saving space." msgstr "" #: ../../tutorial/controlflow.rst:148 msgid "" "We say such an object is :term:`iterable`, that is, suitable as a target for " "functions and constructs that expect something from which they can obtain " "successive items until the supply is exhausted. We have seen that " "the :keyword:`for` statement is such a construct, while an example of a " "function that takes an iterable is :func:`sum`::" msgstr "" #: ../../tutorial/controlflow.rst:154 msgid "" ">>> sum(range(4)) # 0 + 1 + 2 + 3\n" "6" msgstr "" #: ../../tutorial/controlflow.rst:157 msgid "" "Later we will see more functions that return iterables and take iterables as " "arguments. In chapter :ref:`tut-structures`, we will discuss :func:`list` " "in more detail." msgstr "" #: ../../tutorial/controlflow.rst:164 msgid ":keyword:`!break` and :keyword:`!continue` Statements" msgstr "" #: ../../tutorial/controlflow.rst:166 msgid "" "The :keyword:`break` statement breaks out of the innermost " "enclosing :keyword:`for` or :keyword:`while` loop::" msgstr "" #: ../../tutorial/controlflow.rst:169 msgid "" ">>> for n in range(2, 10):\n" "... for x in range(2, n):\n" "... if n % x == 0:\n" "... print(f\"{n} equals {x} * {n//x}\")\n" "... break\n" "...\n" "4 equals 2 * 2\n" "6 equals 2 * 3\n" "8 equals 2 * 4\n" "9 equals 3 * 3" msgstr "" #: ../../tutorial/controlflow.rst:180 msgid "" "The :keyword:`continue` statement continues with the next iteration of the " "loop::" msgstr "" #: ../../tutorial/controlflow.rst:183 msgid "" ">>> for num in range(2, 10):\n" "... if num % 2 == 0:\n" "... print(f\"Found an even number {num}\")\n" "... continue\n" "... print(f\"Found an odd number {num}\")\n" "...\n" "Found an even number 2\n" "Found an odd number 3\n" "Found an even number 4\n" "Found an odd number 5\n" "Found an even number 6\n" "Found an odd number 7\n" "Found an even number 8\n" "Found an odd number 9" msgstr "" #: ../../tutorial/controlflow.rst:202 msgid ":keyword:`!else` Clauses on Loops" msgstr "" #: ../../tutorial/controlflow.rst:204 msgid "" "In a :keyword:`!for` or :keyword:`!while` loop the :keyword:`!break` " "statement may be paired with an :keyword:`!else` clause. If the loop " "finishes without executing the :keyword:`!break`, the :keyword:`!else` " "clause executes." msgstr "" #: ../../tutorial/controlflow.rst:208 msgid "" "In a :keyword:`for` loop, the :keyword:`!else` clause is executed after the " "loop finishes its final iteration, that is, if no break occurred." msgstr "" #: ../../tutorial/controlflow.rst:211 msgid "" "In a :keyword:`while` loop, it's executed after the loop's condition becomes " "false." msgstr "" #: ../../tutorial/controlflow.rst:213 msgid "" "In either kind of loop, the :keyword:`!else` clause is **not** executed if " "the loop was terminated by a :keyword:`break`. Of course, other ways of " "ending the loop early, such as a :keyword:`return` or a raised exception, " "will also skip execution of the :keyword:`else` clause." msgstr "" #: ../../tutorial/controlflow.rst:218 msgid "" "This is exemplified in the following :keyword:`!for` loop, which searches " "for prime numbers::" msgstr "" #: ../../tutorial/controlflow.rst:221 msgid "" ">>> for n in range(2, 10):\n" "... for x in range(2, n):\n" "... if n % x == 0:\n" "... print(n, 'equals', x, '*', n//x)\n" "... break\n" "... else:\n" "... # loop fell through without finding a factor\n" "... print(n, 'is a prime number')\n" "...\n" "2 is a prime number\n" "3 is a prime number\n" "4 equals 2 * 2\n" "5 is a prime number\n" "6 equals 2 * 3\n" "7 is a prime number\n" "8 equals 2 * 4\n" "9 equals 3 * 3" msgstr "" #: ../../tutorial/controlflow.rst:239 msgid "" "(Yes, this is the correct code. Look closely: the ``else`` clause belongs " "to the ``for`` loop, **not** the ``if`` statement.)" msgstr "" #: ../../tutorial/controlflow.rst:242 msgid "" "One way to think of the else clause is to imagine it paired with the ``if`` " "inside the loop. As the loop executes, it will run a sequence like if/if/if/" "else. The ``if`` is inside the loop, encountered a number of times. If the " "condition is ever true, a ``break`` will happen. If the condition is never " "true, the ``else`` clause outside the loop will execute." msgstr "" #: ../../tutorial/controlflow.rst:248 msgid "" "When used with a loop, the ``else`` clause has more in common with the " "``else`` clause of a :keyword:`try` statement than it does with that of " "``if`` statements: a ``try`` statement's ``else`` clause runs when no " "exception occurs, and a loop's ``else`` clause runs when no ``break`` " "occurs. For more on the ``try`` statement and exceptions, see :ref:`tut-" "handling`." msgstr "" #: ../../tutorial/controlflow.rst:258 msgid ":keyword:`!pass` Statements" msgstr "" #: ../../tutorial/controlflow.rst:260 msgid "" "The :keyword:`pass` statement does nothing. It can be used when a statement " "is required syntactically but the program requires no action. For example::" msgstr "" #: ../../tutorial/controlflow.rst:263 msgid "" ">>> while True:\n" "... pass # Busy-wait for keyboard interrupt (Ctrl+C)\n" "..." msgstr "" #: ../../tutorial/controlflow.rst:267 msgid "This is commonly used for creating minimal classes::" msgstr "" #: ../../tutorial/controlflow.rst:269 msgid "" ">>> class MyEmptyClass:\n" "... pass\n" "..." msgstr "" #: ../../tutorial/controlflow.rst:273 msgid "" "Another place :keyword:`pass` can be used is as a place-holder for a " "function or conditional body when you are working on new code, allowing you " "to keep thinking at a more abstract level. The :keyword:`!pass` is silently " "ignored::" msgstr "" #: ../../tutorial/controlflow.rst:277 msgid "" ">>> def initlog(*args):\n" "... pass # Remember to implement this!\n" "..." msgstr "" #: ../../tutorial/controlflow.rst:281 msgid "" "For this last case, many people use the ellipsis literal :code:`...` instead " "of :code:`pass`. This use has no special meaning to Python, and is not part " "of the language definition (you could use any constant expression here), " "but :code:`...` is used conventionally as a placeholder body as well. " "See :ref:`bltin-ellipsis-object`." msgstr "" #: ../../tutorial/controlflow.rst:291 msgid ":keyword:`!match` Statements" msgstr "" #: ../../tutorial/controlflow.rst:293 msgid "" "A :keyword:`match` statement takes an expression and compares its value to " "successive patterns given as one or more case blocks. This is superficially " "similar to a switch statement in C, Java or JavaScript (and many other " "languages), but it's more similar to pattern matching in languages like Rust " "or Haskell. Only the first pattern that matches gets executed and it can " "also extract components (sequence elements or object attributes) from the " "value into variables. If no case matches, none of the branches is executed." msgstr "" #: ../../tutorial/controlflow.rst:302 msgid "" "The simplest form compares a subject value against one or more literals::" msgstr "" #: ../../tutorial/controlflow.rst:304 msgid "" "def http_error(status):\n" " match status:\n" " case 400:\n" " return \"Bad request\"\n" " case 404:\n" " return \"Not found\"\n" " case 418:\n" " return \"I'm a teapot\"\n" " case _:\n" " return \"Something's wrong with the internet\"" msgstr "" #: ../../tutorial/controlflow.rst:315 msgid "" "Note the last block: the \"variable name\" ``_`` acts as a *wildcard* and " "never fails to match." msgstr "" #: ../../tutorial/controlflow.rst:318 msgid "" "You can combine several literals in a single pattern using ``|`` (\"or\")::" msgstr "" #: ../../tutorial/controlflow.rst:320 msgid "" "case 401 | 403 | 404:\n" " return \"Not allowed\"" msgstr "" #: ../../tutorial/controlflow.rst:323 msgid "" "Patterns can look like unpacking assignments, and can be used to bind " "variables::" msgstr "" #: ../../tutorial/controlflow.rst:326 msgid "" "# point is an (x, y) tuple\n" "match point:\n" " case (0, 0):\n" " print(\"Origin\")\n" " case (0, y):\n" " print(f\"Y={y}\")\n" " case (x, 0):\n" " print(f\"X={x}\")\n" " case (x, y):\n" " print(f\"X={x}, Y={y}\")\n" " case _:\n" " raise ValueError(\"Not a point\")" msgstr "" #: ../../tutorial/controlflow.rst:339 msgid "" "Study that one carefully! The first pattern has two literals, and can be " "thought of as an extension of the literal pattern shown above. But the next " "two patterns combine a literal and a variable, and the variable *binds* a " "value from the subject (``point``). The fourth pattern captures two values, " "which makes it conceptually similar to the unpacking assignment ``(x, y) = " "point``." msgstr "" #: ../../tutorial/controlflow.rst:346 msgid "" "If you are using classes to structure your data you can use the class name " "followed by an argument list resembling a constructor, but with the ability " "to capture attributes into variables::" msgstr "" #: ../../tutorial/controlflow.rst:350 msgid "" "class Point:\n" " def __init__(self, x, y):\n" " self.x = x\n" " self.y = y\n" "\n" "def where_is(point):\n" " match point:\n" " case Point(x=0, y=0):\n" " print(\"Origin\")\n" " case Point(x=0, y=y):\n" " print(f\"Y={y}\")\n" " case Point(x=x, y=0):\n" " print(f\"X={x}\")\n" " case Point():\n" " print(\"Somewhere else\")\n" " case _:\n" " print(\"Not a point\")" msgstr "" #: ../../tutorial/controlflow.rst:368 msgid "" "You can use positional parameters with some builtin classes that provide an " "ordering for their attributes (e.g. dataclasses). You can also define a " "specific position for attributes in patterns by setting the " "``__match_args__`` special attribute in your classes. If it's set to (\"x\", " "\"y\"), the following patterns are all equivalent (and all bind the ``y`` " "attribute to the ``var`` variable)::" msgstr "" #: ../../tutorial/controlflow.rst:374 msgid "" "Point(1, var)\n" "Point(1, y=var)\n" "Point(x=1, y=var)\n" "Point(y=var, x=1)" msgstr "" #: ../../tutorial/controlflow.rst:379 msgid "" "A recommended way to read patterns is to look at them as an extended form of " "what you would put on the left of an assignment, to understand which " "variables would be set to what. Only the standalone names (like ``var`` " "above) are assigned to by a match statement. Dotted names (like " "``foo.bar``), attribute names (the ``x=`` and ``y=`` above) or class names " "(recognized by the \"(...)\" next to them like ``Point`` above) are never " "assigned to." msgstr "" #: ../../tutorial/controlflow.rst:386 msgid "" "Patterns can be arbitrarily nested. For example, if we have a short list of " "Points, with ``__match_args__`` added, we could match it like this::" msgstr "" #: ../../tutorial/controlflow.rst:389 msgid "" "class Point:\n" " __match_args__ = ('x', 'y')\n" " def __init__(self, x, y):\n" " self.x = x\n" " self.y = y\n" "\n" "match points:\n" " case []:\n" " print(\"No points\")\n" " case [Point(0, 0)]:\n" " print(\"The origin\")\n" " case [Point(x, y)]:\n" " print(f\"Single point {x}, {y}\")\n" " case [Point(0, y1), Point(0, y2)]:\n" " print(f\"Two on the Y axis at {y1}, {y2}\")\n" " case _:\n" " print(\"Something else\")" msgstr "" #: ../../tutorial/controlflow.rst:407 msgid "" "We can add an ``if`` clause to a pattern, known as a \"guard\". If the " "guard is false, ``match`` goes on to try the next case block. Note that " "value capture happens before the guard is evaluated::" msgstr "" #: ../../tutorial/controlflow.rst:411 msgid "" "match point:\n" " case Point(x, y) if x == y:\n" " print(f\"Y=X at {x}\")\n" " case Point(x, y):\n" " print(f\"Not on the diagonal\")" msgstr "" #: ../../tutorial/controlflow.rst:417 msgid "Several other key features of this statement:" msgstr "" #: ../../tutorial/controlflow.rst:419 msgid "" "Like unpacking assignments, tuple and list patterns have exactly the same " "meaning and actually match arbitrary sequences. An important exception is " "that they don't match iterators or strings." msgstr "" #: ../../tutorial/controlflow.rst:423 msgid "" "Sequence patterns support extended unpacking: ``[x, y, *rest]`` and ``(x, y, " "*rest)`` work similar to unpacking assignments. The name after ``*`` may " "also be ``_``, so ``(x, y, *_)`` matches a sequence of at least two items " "without binding the remaining items." msgstr "" #: ../../tutorial/controlflow.rst:428 msgid "" "Mapping patterns: ``{\"bandwidth\": b, \"latency\": l}`` captures the " "``\"bandwidth\"`` and ``\"latency\"`` values from a dictionary. Unlike " "sequence patterns, extra keys are ignored. An unpacking like ``**rest`` is " "also supported. (But ``**_`` would be redundant, so it is not allowed.)" msgstr "" #: ../../tutorial/controlflow.rst:433 msgid "Subpatterns may be captured using the ``as`` keyword::" msgstr "" #: ../../tutorial/controlflow.rst:435 msgid "case (Point(x1, y1), Point(x2, y2) as p2): ..." msgstr "" #: ../../tutorial/controlflow.rst:437 msgid "" "will capture the second element of the input as ``p2`` (as long as the input " "is a sequence of two points)" msgstr "" #: ../../tutorial/controlflow.rst:440 msgid "" "Most literals are compared by equality, however the singletons ``True``, " "``False`` and ``None`` are compared by identity." msgstr "" #: ../../tutorial/controlflow.rst:443 msgid "" "Patterns may use named constants. These must be dotted names to prevent " "them from being interpreted as capture variables::" msgstr "" #: ../../tutorial/controlflow.rst:446 msgid "" "from enum import Enum\n" "class Color(Enum):\n" " RED = 'red'\n" " GREEN = 'green'\n" " BLUE = 'blue'\n" "\n" "color = Color(input(\"Enter your choice of 'red', 'blue' or 'green': \"))\n" "\n" "match color:\n" " case Color.RED:\n" " print(\"I see red!\")\n" " case Color.GREEN:\n" " print(\"Grass is green\")\n" " case Color.BLUE:\n" " print(\"I'm feeling the blues :(\")" msgstr "" #: ../../tutorial/controlflow.rst:462 msgid "" "For a more detailed explanation and additional examples, you can look " "into :pep:`636` which is written in a tutorial format." msgstr "" #: ../../tutorial/controlflow.rst:468 msgid "Defining Functions" msgstr "" #: ../../tutorial/controlflow.rst:470 msgid "" "We can create a function that writes the Fibonacci series to an arbitrary " "boundary::" msgstr "" #: ../../tutorial/controlflow.rst:473 msgid "" ">>> def fib(n): # write Fibonacci series less than n\n" "... \"\"\"Print a Fibonacci series less than n.\"\"\"\n" "... a, b = 0, 1\n" "... while a < n:\n" "... print(a, end=' ')\n" "... a, b = b, a+b\n" "... print()\n" "...\n" ">>> # Now call the function we just defined:\n" ">>> fib(2000)\n" "0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597" msgstr "" #: ../../tutorial/controlflow.rst:490 msgid "" "The keyword :keyword:`def` introduces a function *definition*. It must be " "followed by the function name and the parenthesized list of formal " "parameters. The statements that form the body of the function start at the " "next line, and must be indented." msgstr "" #: ../../tutorial/controlflow.rst:495 msgid "" "The first statement of the function body can optionally be a string literal; " "this string literal is the function's documentation string, " "or :dfn:`docstring`. (More about docstrings can be found in the " "section :ref:`tut-docstrings`.) There are tools which use docstrings to " "automatically produce online or printed documentation, or to let the user " "interactively browse through code; it's good practice to include docstrings " "in code that you write, so make a habit of it." msgstr "" #: ../../tutorial/controlflow.rst:502 msgid "" "The *execution* of a function introduces a new symbol table used for the " "local variables of the function. More precisely, all variable assignments " "in a function store the value in the local symbol table; whereas variable " "references first look in the local symbol table, then in the local symbol " "tables of enclosing functions, then in the global symbol table, and finally " "in the table of built-in names. Thus, global variables and variables of " "enclosing functions cannot be directly assigned a value within a function " "(unless, for global variables, named in a :keyword:`global` statement, or, " "for variables of enclosing functions, named in a :keyword:`nonlocal` " "statement), although they may be referenced." msgstr "" #: ../../tutorial/controlflow.rst:513 msgid "" "The actual parameters (arguments) to a function call are introduced in the " "local symbol table of the called function when it is called; thus, arguments " "are passed using *call by value* (where the *value* is always an object " "*reference*, not the value of the object). [#]_ When a function calls " "another function, or calls itself recursively, a new local symbol table is " "created for that call." msgstr "" #: ../../tutorial/controlflow.rst:520 msgid "" "A function definition associates the function name with the function object " "in the current symbol table. The interpreter recognizes the object pointed " "to by that name as a user-defined function. Other names can also point to " "that same function object and can also be used to access the function::" msgstr "" #: ../../tutorial/controlflow.rst:525 msgid "" ">>> fib\n" "\n" ">>> f = fib\n" ">>> f(100)\n" "0 1 1 2 3 5 8 13 21 34 55 89" msgstr "" #: ../../tutorial/controlflow.rst:531 msgid "" "Coming from other languages, you might object that ``fib`` is not a function " "but a procedure since it doesn't return a value. In fact, even functions " "without a :keyword:`return` statement do return a value, albeit a rather " "boring one. This value is called ``None`` (it's a built-in name). Writing " "the value ``None`` is normally suppressed by the interpreter if it would be " "the only value written. You can see it if you really want to " "using :func:`print`::" msgstr "" #: ../../tutorial/controlflow.rst:538 msgid "" ">>> fib(0)\n" ">>> print(fib(0))\n" "None" msgstr "" #: ../../tutorial/controlflow.rst:542 msgid "" "It is simple to write a function that returns a list of the numbers of the " "Fibonacci series, instead of printing it::" msgstr "" #: ../../tutorial/controlflow.rst:545 msgid "" ">>> def fib2(n): # return Fibonacci series up to n\n" "... \"\"\"Return a list containing the Fibonacci series up to n.\"\"\"\n" "... result = []\n" "... a, b = 0, 1\n" "... while a < n:\n" "... result.append(a) # see below\n" "... a, b = b, a+b\n" "... return result\n" "...\n" ">>> f100 = fib2(100) # call it\n" ">>> f100 # write the result\n" "[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]" msgstr "" #: ../../tutorial/controlflow.rst:558 msgid "This example, as usual, demonstrates some new Python features:" msgstr "" #: ../../tutorial/controlflow.rst:560 msgid "" "The :keyword:`return` statement returns with a value from a " "function. :keyword:`!return` without an expression argument returns " "``None``. Falling off the end of a function also returns ``None``." msgstr "" #: ../../tutorial/controlflow.rst:564 msgid "" "The statement ``result.append(a)`` calls a *method* of the list object " "``result``. A method is a function that 'belongs' to an object and is named " "``obj.methodname``, where ``obj`` is some object (this may be an " "expression), and ``methodname`` is the name of a method that is defined by " "the object's type. Different types define different methods. Methods of " "different types may have the same name without causing ambiguity. (It is " "possible to define your own object types and methods, using *classes*, " "see :ref:`tut-classes`) The method :meth:`~list.append` shown in the example " "is defined for list objects; it adds a new element at the end of the list. " "In this example it is equivalent to ``result = result + [a]``, but more " "efficient." msgstr "" #: ../../tutorial/controlflow.rst:579 msgid "More on Defining Functions" msgstr "" #: ../../tutorial/controlflow.rst:581 msgid "" "It is also possible to define functions with a variable number of arguments. " "There are three forms, which can be combined." msgstr "" #: ../../tutorial/controlflow.rst:588 msgid "Default Argument Values" msgstr "" #: ../../tutorial/controlflow.rst:590 msgid "" "The most useful form is to specify a default value for one or more " "arguments. This creates a function that can be called with fewer arguments " "than it is defined to allow. For example::" msgstr "" #: ../../tutorial/controlflow.rst:594 msgid "" "def ask_ok(prompt, retries=4, reminder='Please try again!'):\n" " while True:\n" " reply = input(prompt)\n" " if reply in {'y', 'ye', 'yes'}:\n" " return True\n" " if reply in {'n', 'no', 'nop', 'nope'}:\n" " return False\n" " retries = retries - 1\n" " if retries < 0:\n" " raise ValueError('invalid user response')\n" " print(reminder)" msgstr "" #: ../../tutorial/controlflow.rst:606 msgid "This function can be called in several ways:" msgstr "" #: ../../tutorial/controlflow.rst:608 msgid "" "giving only the mandatory argument: ``ask_ok('Do you really want to quit?')``" msgstr "" #: ../../tutorial/controlflow.rst:610 msgid "" "giving one of the optional arguments: ``ask_ok('OK to overwrite the file?', " "2)``" msgstr "" #: ../../tutorial/controlflow.rst:612 msgid "" "or even giving all arguments: ``ask_ok('OK to overwrite the file?', 2, 'Come " "on, only yes or no!')``" msgstr "" #: ../../tutorial/controlflow.rst:615 msgid "" "This example also introduces the :keyword:`in` keyword. This tests whether " "or not a sequence contains a certain value." msgstr "" #: ../../tutorial/controlflow.rst:618 msgid "" "The default values are evaluated at the point of function definition in the " "*defining* scope, so that ::" msgstr "" #: ../../tutorial/controlflow.rst:621 msgid "" "i = 5\n" "\n" "def f(arg=i):\n" " print(arg)\n" "\n" "i = 6\n" "f()" msgstr "" #: ../../tutorial/controlflow.rst:629 msgid "will print ``5``." msgstr "" #: ../../tutorial/controlflow.rst:631 msgid "" "**Important warning:** The default value is evaluated only once. This makes " "a difference when the default is a mutable object such as a list, " "dictionary, or instances of most classes. For example, the following " "function accumulates the arguments passed to it on subsequent calls::" msgstr "" #: ../../tutorial/controlflow.rst:636 msgid "" "def f(a, L=[]):\n" " L.append(a)\n" " return L\n" "\n" "print(f(1))\n" "print(f(2))\n" "print(f(3))" msgstr "" #: ../../tutorial/controlflow.rst:644 msgid "This will print ::" msgstr "" #: ../../tutorial/controlflow.rst:646 msgid "" "[1]\n" "[1, 2]\n" "[1, 2, 3]" msgstr "" #: ../../tutorial/controlflow.rst:650 msgid "" "If you don't want the default to be shared between subsequent calls, you can " "write the function like this instead::" msgstr "" #: ../../tutorial/controlflow.rst:653 msgid "" "def f(a, L=None):\n" " if L is None:\n" " L = []\n" " L.append(a)\n" " return L" msgstr "" #: ../../tutorial/controlflow.rst:663 msgid "Keyword Arguments" msgstr "" #: ../../tutorial/controlflow.rst:665 msgid "" "Functions can also be called using :term:`keyword arguments ` of the form ``kwarg=value``. For instance, the following " "function::" msgstr "" #: ../../tutorial/controlflow.rst:668 msgid "" "def parrot(voltage, state='a stiff', action='voom', type='Norwegian Blue'):\n" " print(\"-- This parrot wouldn't\", action, end=' ')\n" " print(\"if you put\", voltage, \"volts through it.\")\n" " print(\"-- Lovely plumage, the\", type)\n" " print(\"-- It's\", state, \"!\")" msgstr "" #: ../../tutorial/controlflow.rst:674 msgid "" "accepts one required argument (``voltage``) and three optional arguments " "(``state``, ``action``, and ``type``). This function can be called in any " "of the following ways::" msgstr "" #: ../../tutorial/controlflow.rst:678 msgid "" "parrot(1000) # 1 positional " "argument\n" "parrot(voltage=1000) # 1 keyword argument\n" "parrot(voltage=1000000, action='VOOOOOM') # 2 keyword arguments\n" "parrot(action='VOOOOOM', voltage=1000000) # 2 keyword arguments\n" "parrot('a million', 'bereft of life', 'jump') # 3 positional " "arguments\n" "parrot('a thousand', state='pushing up the daisies') # 1 positional, 1 " "keyword" msgstr "" #: ../../tutorial/controlflow.rst:685 msgid "but all the following calls would be invalid::" msgstr "" #: ../../tutorial/controlflow.rst:687 msgid "" "parrot() # required argument missing\n" "parrot(voltage=5.0, 'dead') # non-keyword argument after a keyword " "argument\n" "parrot(110, voltage=220) # duplicate value for the same argument\n" "parrot(actor='John Cleese') # unknown keyword argument" msgstr "" #: ../../tutorial/controlflow.rst:692 msgid "" "In a function call, keyword arguments must follow positional arguments. All " "the keyword arguments passed must match one of the arguments accepted by the " "function (e.g. ``actor`` is not a valid argument for the ``parrot`` " "function), and their order is not important. This also includes non-" "optional arguments (e.g. ``parrot(voltage=1000)`` is valid too). No argument " "may receive a value more than once. Here's an example that fails due to this " "restriction::" msgstr "" #: ../../tutorial/controlflow.rst:700 msgid "" ">>> def function(a):\n" "... pass\n" "...\n" ">>> function(0, a=0)\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" "TypeError: function() got multiple values for argument 'a'" msgstr "" #: ../../tutorial/controlflow.rst:708 msgid "" "When a final formal parameter of the form ``**name`` is present, it receives " "a dictionary (see :ref:`typesmapping`) containing all keyword arguments " "except for those corresponding to a formal parameter. This may be combined " "with a formal parameter of the form ``*name`` (described in the next " "subsection) which receives a :ref:`tuple ` containing the " "positional arguments beyond the formal parameter list. (``*name`` must " "occur before ``**name``.) For example, if we define a function like this::" msgstr "" #: ../../tutorial/controlflow.rst:716 msgid "" "def cheeseshop(kind, *arguments, **keywords):\n" " print(\"-- Do you have any\", kind, \"?\")\n" " print(\"-- I'm sorry, we're all out of\", kind)\n" " for arg in arguments:\n" " print(arg)\n" " print(\"-\" * 40)\n" " for kw in keywords:\n" " print(kw, \":\", keywords[kw])" msgstr "" #: ../../tutorial/controlflow.rst:725 msgid "It could be called like this::" msgstr "" #: ../../tutorial/controlflow.rst:727 msgid "" "cheeseshop(\"Limburger\", \"It's very runny, sir.\",\n" " \"It's really very, VERY runny, sir.\",\n" " shopkeeper=\"Michael Palin\",\n" " client=\"John Cleese\",\n" " sketch=\"Cheese Shop Sketch\")" msgstr "" #: ../../tutorial/controlflow.rst:733 msgid "and of course it would print:" msgstr "" #: ../../tutorial/controlflow.rst:735 msgid "" "-- Do you have any Limburger ?\n" "-- I'm sorry, we're all out of Limburger\n" "It's very runny, sir.\n" "It's really very, VERY runny, sir.\n" "----------------------------------------\n" "shopkeeper : Michael Palin\n" "client : John Cleese\n" "sketch : Cheese Shop Sketch" msgstr "" #: ../../tutorial/controlflow.rst:746 msgid "" "Note that the order in which the keyword arguments are printed is guaranteed " "to match the order in which they were provided in the function call." msgstr "" #: ../../tutorial/controlflow.rst:750 msgid "Special parameters" msgstr "" #: ../../tutorial/controlflow.rst:752 msgid "" "By default, arguments may be passed to a Python function either by position " "or explicitly by keyword. For readability and performance, it makes sense to " "restrict the way arguments can be passed so that a developer need only look " "at the function definition to determine if items are passed by position, by " "position or keyword, or by keyword." msgstr "" #: ../../tutorial/controlflow.rst:758 msgid "A function definition may look like:" msgstr "" #: ../../tutorial/controlflow.rst:760 msgid "" "def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2):\n" " ----------- ---------- ----------\n" " | | |\n" " | Positional or keyword |\n" " | - Keyword only\n" " -- Positional only" msgstr "" #: ../../tutorial/controlflow.rst:769 msgid "" "where ``/`` and ``*`` are optional. If used, these symbols indicate the kind " "of parameter by how the arguments may be passed to the function: positional-" "only, positional-or-keyword, and keyword-only. Keyword parameters are also " "referred to as named parameters." msgstr "" #: ../../tutorial/controlflow.rst:776 msgid "Positional-or-Keyword Arguments" msgstr "" #: ../../tutorial/controlflow.rst:778 msgid "" "If ``/`` and ``*`` are not present in the function definition, arguments may " "be passed to a function by position or by keyword." msgstr "" #: ../../tutorial/controlflow.rst:783 msgid "Positional-Only Parameters" msgstr "" #: ../../tutorial/controlflow.rst:785 msgid "" "Looking at this in a bit more detail, it is possible to mark certain " "parameters as *positional-only*. If *positional-only*, the parameters' order " "matters, and the parameters cannot be passed by keyword. Positional-only " "parameters are placed before a ``/`` (forward-slash). The ``/`` is used to " "logically separate the positional-only parameters from the rest of the " "parameters. If there is no ``/`` in the function definition, there are no " "positional-only parameters." msgstr "" #: ../../tutorial/controlflow.rst:793 msgid "" "Parameters following the ``/`` may be *positional-or-keyword* or *keyword-" "only*." msgstr "" #: ../../tutorial/controlflow.rst:797 msgid "Keyword-Only Arguments" msgstr "" #: ../../tutorial/controlflow.rst:799 msgid "" "To mark parameters as *keyword-only*, indicating the parameters must be " "passed by keyword argument, place an ``*`` in the arguments list just before " "the first *keyword-only* parameter." msgstr "" #: ../../tutorial/controlflow.rst:805 msgid "Function Examples" msgstr "" #: ../../tutorial/controlflow.rst:807 msgid "" "Consider the following example function definitions paying close attention " "to the markers ``/`` and ``*``::" msgstr "" #: ../../tutorial/controlflow.rst:810 msgid "" ">>> def standard_arg(arg):\n" "... print(arg)\n" "...\n" ">>> def pos_only_arg(arg, /):\n" "... print(arg)\n" "...\n" ">>> def kwd_only_arg(*, arg):\n" "... print(arg)\n" "...\n" ">>> def combined_example(pos_only, /, standard, *, kwd_only):\n" "... print(pos_only, standard, kwd_only)" msgstr "" #: ../../tutorial/controlflow.rst:823 msgid "" "The first function definition, ``standard_arg``, the most familiar form, " "places no restrictions on the calling convention and arguments may be passed " "by position or keyword::" msgstr "" #: ../../tutorial/controlflow.rst:827 msgid "" ">>> standard_arg(2)\n" "2\n" "\n" ">>> standard_arg(arg=2)\n" "2" msgstr "" #: ../../tutorial/controlflow.rst:833 msgid "" "The second function ``pos_only_arg`` is restricted to only use positional " "parameters as there is a ``/`` in the function definition::" msgstr "" #: ../../tutorial/controlflow.rst:836 msgid "" ">>> pos_only_arg(1)\n" "1\n" "\n" ">>> pos_only_arg(arg=1)\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" "TypeError: pos_only_arg() got some positional-only arguments passed as " "keyword arguments: 'arg'" msgstr "" #: ../../tutorial/controlflow.rst:844 msgid "" "The third function ``kwd_only_arg`` only allows keyword arguments as " "indicated by a ``*`` in the function definition::" msgstr "" #: ../../tutorial/controlflow.rst:847 msgid "" ">>> kwd_only_arg(3)\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" "TypeError: kwd_only_arg() takes 0 positional arguments but 1 was given\n" "\n" ">>> kwd_only_arg(arg=3)\n" "3" msgstr "" #: ../../tutorial/controlflow.rst:855 msgid "" "And the last uses all three calling conventions in the same function " "definition::" msgstr "" #: ../../tutorial/controlflow.rst:858 msgid "" ">>> combined_example(1, 2, 3)\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" "TypeError: combined_example() takes 2 positional arguments but 3 were given\n" "\n" ">>> combined_example(1, 2, kwd_only=3)\n" "1 2 3\n" "\n" ">>> combined_example(1, standard=2, kwd_only=3)\n" "1 2 3\n" "\n" ">>> combined_example(pos_only=1, standard=2, kwd_only=3)\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" "TypeError: combined_example() got some positional-only arguments passed as " "keyword arguments: 'pos_only'" msgstr "" #: ../../tutorial/controlflow.rst:875 msgid "" "Finally, consider this function definition which has a potential collision " "between the positional argument ``name`` and ``**kwds`` which has ``name`` " "as a key::" msgstr "" #: ../../tutorial/controlflow.rst:877 msgid "" "def foo(name, **kwds):\n" " return 'name' in kwds" msgstr "" #: ../../tutorial/controlflow.rst:880 msgid "" "There is no possible call that will make it return ``True`` as the keyword " "``'name'`` will always bind to the first parameter. For example::" msgstr "" #: ../../tutorial/controlflow.rst:883 msgid "" ">>> foo(1, **{'name': 2})\n" "Traceback (most recent call last):\n" " File \"\", line 1, in \n" "TypeError: foo() got multiple values for argument 'name'\n" ">>>" msgstr "" #: ../../tutorial/controlflow.rst:889 msgid "" "But using ``/`` (positional only arguments), it is possible since it allows " "``name`` as a positional argument and ``'name'`` as a key in the keyword " "arguments::" msgstr "" #: ../../tutorial/controlflow.rst:891 msgid "" ">>> def foo(name, /, **kwds):\n" "... return 'name' in kwds\n" "...\n" ">>> foo(1, **{'name': 2})\n" "True" msgstr "" #: ../../tutorial/controlflow.rst:897 msgid "" "In other words, the names of positional-only parameters can be used in " "``**kwds`` without ambiguity." msgstr "" #: ../../tutorial/controlflow.rst:902 msgid "Recap" msgstr "" #: ../../tutorial/controlflow.rst:904 msgid "" "The use case will determine which parameters to use in the function " "definition::" msgstr "" #: ../../tutorial/controlflow.rst:906 msgid "def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2):" msgstr "" #: ../../tutorial/controlflow.rst:908 msgid "As guidance:" msgstr "" #: ../../tutorial/controlflow.rst:910 msgid "" "Use positional-only if you want the name of the parameters to not be " "available to the user. This is useful when parameter names have no real " "meaning, if you want to enforce the order of the arguments when the function " "is called or if you need to take some positional parameters and arbitrary " "keywords." msgstr "" #: ../../tutorial/controlflow.rst:915 msgid "" "Use keyword-only when names have meaning and the function definition is more " "understandable by being explicit with names or you want to prevent users " "relying on the position of the argument being passed." msgstr "" #: ../../tutorial/controlflow.rst:918 msgid "" "For an API, use positional-only to prevent breaking API changes if the " "parameter's name is modified in the future." msgstr "" #: ../../tutorial/controlflow.rst:924 msgid "Arbitrary Argument Lists" msgstr "" #: ../../tutorial/controlflow.rst:929 msgid "" "Finally, the least frequently used option is to specify that a function can " "be called with an arbitrary number of arguments. These arguments will be " "wrapped up in a tuple (see :ref:`tut-tuples`). Before the variable number " "of arguments, zero or more normal arguments may occur. ::" msgstr "" #: ../../tutorial/controlflow.rst:934 msgid "" "def write_multiple_items(file, separator, *args):\n" " file.write(separator.join(args))" msgstr "" #: ../../tutorial/controlflow.rst:938 msgid "" "Normally, these *variadic* arguments will be last in the list of formal " "parameters, because they scoop up all remaining input arguments that are " "passed to the function. Any formal parameters which occur after the " "``*args`` parameter are 'keyword-only' arguments, meaning that they can only " "be used as keywords rather than positional arguments. ::" msgstr "" #: ../../tutorial/controlflow.rst:944 msgid "" ">>> def concat(*args, sep=\"/\"):\n" "... return sep.join(args)\n" "...\n" ">>> concat(\"earth\", \"mars\", \"venus\")\n" "'earth/mars/venus'\n" ">>> concat(\"earth\", \"mars\", \"venus\", sep=\".\")\n" "'earth.mars.venus'" msgstr "" #: ../../tutorial/controlflow.rst:955 msgid "Unpacking Argument Lists" msgstr "" #: ../../tutorial/controlflow.rst:957 msgid "" "The reverse situation occurs when the arguments are already in a list or " "tuple but need to be unpacked for a function call requiring separate " "positional arguments. For instance, the built-in :func:`range` function " "expects separate *start* and *stop* arguments. If they are not available " "separately, write the function call with the ``*``\\ -operator to unpack " "the arguments out of a list or tuple::" msgstr "" #: ../../tutorial/controlflow.rst:964 msgid "" ">>> list(range(3, 6)) # normal call with separate arguments\n" "[3, 4, 5]\n" ">>> args = [3, 6]\n" ">>> list(range(*args)) # call with arguments unpacked from a " "list\n" "[3, 4, 5]" msgstr "" #: ../../tutorial/controlflow.rst:973 msgid "" "In the same fashion, dictionaries can deliver keyword arguments with the " "``**``\\ -operator::" msgstr "" #: ../../tutorial/controlflow.rst:976 msgid "" ">>> def parrot(voltage, state='a stiff', action='voom'):\n" "... print(\"-- This parrot wouldn't\", action, end=' ')\n" "... print(\"if you put\", voltage, \"volts through it.\", end=' ')\n" "... print(\"E's\", state, \"!\")\n" "...\n" ">>> d = {\"voltage\": \"four million\", \"state\": \"bleedin' demised\", " "\"action\": \"VOOM\"}\n" ">>> parrot(**d)\n" "-- This parrot wouldn't VOOM if you put four million volts through it. E's " "bleedin' demised !" msgstr "" #: ../../tutorial/controlflow.rst:989 msgid "Lambda Expressions" msgstr "" #: ../../tutorial/controlflow.rst:991 msgid "" "Small anonymous functions can be created with the :keyword:`lambda` keyword. " "This function returns the sum of its two arguments: ``lambda a, b: a+b``. " "Lambda functions can be used wherever function objects are required. They " "are syntactically restricted to a single expression. Semantically, they are " "just syntactic sugar for a normal function definition. Like nested function " "definitions, lambda functions can reference variables from the containing " "scope::" msgstr "" #: ../../tutorial/controlflow.rst:999 msgid "" ">>> def make_incrementor(n):\n" "... return lambda x: x + n\n" "...\n" ">>> f = make_incrementor(42)\n" ">>> f(0)\n" "42\n" ">>> f(1)\n" "43" msgstr "" #: ../../tutorial/controlflow.rst:1008 msgid "" "The above example uses a lambda expression to return a function. Another " "use is to pass a small function as an argument. For " "instance, :meth:`list.sort` takes a sorting key function *key* which can be " "a lambda function::" msgstr "" #: ../../tutorial/controlflow.rst:1012 msgid "" ">>> pairs = [(1, 'one'), (2, 'two'), (3, 'three'), (4, 'four')]\n" ">>> pairs.sort(key=lambda pair: pair[1])\n" ">>> pairs\n" "[(4, 'four'), (1, 'one'), (3, 'three'), (2, 'two')]" msgstr "" #: ../../tutorial/controlflow.rst:1021 msgid "Documentation Strings" msgstr "" #: ../../tutorial/controlflow.rst:1028 msgid "" "Here are some conventions about the content and formatting of documentation " "strings." msgstr "" #: ../../tutorial/controlflow.rst:1031 msgid "" "The first line should always be a short, concise summary of the object's " "purpose. For brevity, it should not explicitly state the object's name or " "type, since these are available by other means (except if the name happens " "to be a verb describing a function's operation). This line should begin " "with a capital letter and end with a period." msgstr "" #: ../../tutorial/controlflow.rst:1037 msgid "" "If there are more lines in the documentation string, the second line should " "be blank, visually separating the summary from the rest of the description. " "The following lines should be one or more paragraphs describing the object's " "calling conventions, its side effects, etc." msgstr "" #: ../../tutorial/controlflow.rst:1042 msgid "" "The Python parser strips indentation from multi-line string literals when " "they serve as module, class, or function docstrings." msgstr "" #: ../../tutorial/controlflow.rst:1045 msgid "Here is an example of a multi-line docstring::" msgstr "" #: ../../tutorial/controlflow.rst:1047 msgid "" ">>> def my_function():\n" "... \"\"\"Do nothing, but document it.\n" "...\n" "... No, really, it doesn't do anything:\n" "...\n" "... >>> my_function()\n" "... >>>\n" "... \"\"\"\n" "... pass\n" "...\n" ">>> print(my_function.__doc__)\n" "Do nothing, but document it.\n" "\n" "No, really, it doesn't do anything:\n" "\n" " >>> my_function()\n" " >>>" msgstr "" #: ../../tutorial/controlflow.rst:1069 msgid "Function Annotations" msgstr "" #: ../../tutorial/controlflow.rst:1077 msgid "" ":ref:`Function annotations ` are completely optional metadata " "information about the types used by user-defined functions (see :pep:`3107` " "and :pep:`484` for more information)." msgstr "" #: ../../tutorial/controlflow.rst:1081 msgid "" ":term:`Annotations ` are stored in " "the :attr:`~object.__annotations__` attribute of the function as a " "dictionary and have no effect on any other part of the function. Parameter " "annotations are defined by a colon after the parameter name, followed by an " "expression evaluating to the value of the annotation. Return annotations " "are defined by a literal ``->``, followed by an expression, between the " "parameter list and the colon denoting the end of the :keyword:`def` " "statement. The following example has a required argument, an optional " "argument, and the return value annotated::" msgstr "" #: ../../tutorial/controlflow.rst:1090 msgid "" ">>> def f(ham: str, eggs: str = 'eggs') -> str:\n" "... print(\"Annotations:\", f.__annotations__)\n" "... print(\"Arguments:\", ham, eggs)\n" "... return ham + ' and ' + eggs\n" "...\n" ">>> f('spam')\n" "Annotations: {'ham': , 'return': , 'eggs': }\n" "Arguments: spam eggs\n" "'spam and eggs'" msgstr "" #: ../../tutorial/controlflow.rst:1103 msgid "Intermezzo: Coding Style" msgstr "" #: ../../tutorial/controlflow.rst:1108 msgid "" "Now that you are about to write longer, more complex pieces of Python, it is " "a good time to talk about *coding style*. Most languages can be written (or " "more concisely, *formatted*) in different styles; some are more readable " "than others. Making it easy for others to read your code is always a good " "idea, and adopting a nice coding style helps tremendously for that." msgstr "" #: ../../tutorial/controlflow.rst:1114 msgid "" "For Python, :pep:`8` has emerged as the style guide that most projects " "adhere to; it promotes a very readable and eye-pleasing coding style. Every " "Python developer should read it at some point; here are the most important " "points extracted for you:" msgstr "" #: ../../tutorial/controlflow.rst:1119 msgid "Use 4-space indentation, and no tabs." msgstr "" #: ../../tutorial/controlflow.rst:1121 msgid "" "4 spaces are a good compromise between small indentation (allows greater " "nesting depth) and large indentation (easier to read). Tabs introduce " "confusion, and are best left out." msgstr "" #: ../../tutorial/controlflow.rst:1125 msgid "Wrap lines so that they don't exceed 79 characters." msgstr "" #: ../../tutorial/controlflow.rst:1127 msgid "" "This helps users with small displays and makes it possible to have several " "code files side-by-side on larger displays." msgstr "" #: ../../tutorial/controlflow.rst:1130 msgid "" "Use blank lines to separate functions and classes, and larger blocks of code " "inside functions." msgstr "" #: ../../tutorial/controlflow.rst:1133 msgid "When possible, put comments on a line of their own." msgstr "" #: ../../tutorial/controlflow.rst:1135 msgid "Use docstrings." msgstr "" #: ../../tutorial/controlflow.rst:1137 msgid "" "Use spaces around operators and after commas, but not directly inside " "bracketing constructs: ``a = f(1, 2) + g(3, 4)``." msgstr "" #: ../../tutorial/controlflow.rst:1140 msgid "" "Name your classes and functions consistently; the convention is to use " "``UpperCamelCase`` for classes and ``lowercase_with_underscores`` for " "functions and methods. Always use ``self`` as the name for the first method " "argument (see :ref:`tut-firstclasses` for more on classes and methods)." msgstr "" #: ../../tutorial/controlflow.rst:1145 msgid "" "Don't use fancy encodings if your code is meant to be used in international " "environments. Python's default, UTF-8, or even plain ASCII work best in any " "case." msgstr "" #: ../../tutorial/controlflow.rst:1149 msgid "" "Likewise, don't use non-ASCII characters in identifiers if there is only the " "slightest chance people speaking a different language will read or maintain " "the code." msgstr "" #: ../../tutorial/controlflow.rst:1155 msgid "Footnotes" msgstr "" #: ../../tutorial/controlflow.rst:1156 msgid "" "Actually, *call by object reference* would be a better description, since if " "a mutable object is passed, the caller will see any changes the callee makes " "to it (items inserted into a list)." msgstr "" #: ../../tutorial/controlflow.rst:48 msgid "statement" msgstr "" #: ../../tutorial/controlflow.rst:48 msgid "for" msgstr "" #: ../../tutorial/controlflow.rst:254 msgid "..." msgstr "" #: ../../tutorial/controlflow.rst:254 msgid "ellipsis literal" msgstr "" #: ../../tutorial/controlflow.rst:485 ../../tutorial/controlflow.rst:1023 msgid "documentation strings" msgstr "" #: ../../tutorial/controlflow.rst:485 ../../tutorial/controlflow.rst:1023 msgid "docstrings" msgstr "" #: ../../tutorial/controlflow.rst:485 ../../tutorial/controlflow.rst:1023 msgid "strings, documentation" msgstr "" #: ../../tutorial/controlflow.rst:926 msgid "* (asterisk)" msgstr "" #: ../../tutorial/controlflow.rst:926 ../../tutorial/controlflow.rst:970 msgid "in function calls" msgstr "" #: ../../tutorial/controlflow.rst:970 msgid "**" msgstr "" #: ../../tutorial/controlflow.rst:1072 msgid "function" msgstr "" #: ../../tutorial/controlflow.rst:1072 msgid "annotations" msgstr "" #: ../../tutorial/controlflow.rst:1072 msgid "->" msgstr "" #: ../../tutorial/controlflow.rst:1072 msgid "function annotations" msgstr "" #: ../../tutorial/controlflow.rst:1072 msgid ": (colon)" msgstr "" #: ../../tutorial/controlflow.rst:1106 msgid "coding" msgstr "" #: ../../tutorial/controlflow.rst:1106 msgid "style" msgstr ""