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# SOME DESCRIPTIVE TITLE.
# Copyright (C) 2001 Python Software Foundation
# This file is distributed under the same license as the Python package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
# Translators:
# Alireza Shabani (Revisto) <theRevisto@gmail.com>, 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) <theRevisto@gmail.com>, 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/datastructures.rst:5
msgid "Data Structures"
msgstr ""
#: ../../tutorial/datastructures.rst:7
msgid ""
"This chapter describes some things you've learned about already in more "
"detail, and adds some new things as well."
msgstr ""
#: ../../tutorial/datastructures.rst:13
msgid "More on Lists"
msgstr ""
#: ../../tutorial/datastructures.rst:15
msgid ""
"The :ref:`list <typesseq-list>` data type has some more methods. Here are "
"all of the methods of list objects:"
msgstr ""
#: ../../tutorial/datastructures.rst:21
msgid "Add an item to the end of the list. Similar to ``a[len(a):] = [x]``."
msgstr ""
#: ../../tutorial/datastructures.rst:27
msgid ""
"Extend the list by appending all the items from the iterable. Similar to "
"``a[len(a):] = iterable``."
msgstr ""
#: ../../tutorial/datastructures.rst:34
msgid ""
"Insert an item at a given position. The first argument is the index of the "
"element before which to insert, so ``a.insert(0, x)`` inserts at the front "
"of the list, and ``a.insert(len(a), x)`` is equivalent to ``a.append(x)``."
msgstr ""
#: ../../tutorial/datastructures.rst:42
msgid ""
"Remove the first item from the list whose value is equal to *value*. It "
"raises a :exc:`ValueError` if there is no such item."
msgstr ""
#: ../../tutorial/datastructures.rst:49
msgid ""
"Remove the item at the given position in the list, and return it. If no "
"index is specified, ``a.pop()`` removes and returns the last item in the "
"list. It raises an :exc:`IndexError` if the list is empty or the index is "
"outside the list range."
msgstr ""
#: ../../tutorial/datastructures.rst:58
msgid "Remove all items from the list. Similar to ``del a[:]``."
msgstr ""
#: ../../tutorial/datastructures.rst:64
msgid ""
"Return zero-based index of the first occurrence of *value* in the list. "
"Raises a :exc:`ValueError` if there is no such item."
msgstr ""
#: ../../tutorial/datastructures.rst:67
msgid ""
"The optional arguments *start* and *end* are interpreted as in the slice "
"notation and are used to limit the search to a particular subsequence of the "
"list. The returned index is computed relative to the beginning of the full "
"sequence rather than the *start* argument."
msgstr ""
#: ../../tutorial/datastructures.rst:76
msgid "Return the number of times *value* appears in the list."
msgstr ""
#: ../../tutorial/datastructures.rst:82
msgid ""
"Sort the items of the list in place (the arguments can be used for sort "
"customization, see :func:`sorted` for their explanation)."
msgstr ""
#: ../../tutorial/datastructures.rst:89
msgid "Reverse the elements of the list in place."
msgstr ""
#: ../../tutorial/datastructures.rst:95
msgid "Return a shallow copy of the list. Similar to ``a[:]``."
msgstr ""
#: ../../tutorial/datastructures.rst:98
msgid "An example that uses most of the list methods::"
msgstr ""
#: ../../tutorial/datastructures.rst:100
msgid ""
">>> fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', "
"'banana']\n"
">>> fruits.count('apple')\n"
"2\n"
">>> fruits.count('tangerine')\n"
"0\n"
">>> fruits.index('banana')\n"
"3\n"
">>> fruits.index('banana', 4) # Find next banana starting at position 4\n"
"6\n"
">>> fruits.reverse()\n"
">>> fruits\n"
"['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange']\n"
">>> fruits.append('grape')\n"
">>> fruits\n"
"['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange', 'grape']\n"
">>> fruits.sort()\n"
">>> fruits\n"
"['apple', 'apple', 'banana', 'banana', 'grape', 'kiwi', 'orange', 'pear']\n"
">>> fruits.pop()\n"
"'pear'"
msgstr ""
#: ../../tutorial/datastructures.rst:121
msgid ""
"You might have noticed that methods like ``insert``, ``remove`` or ``sort`` "
"that only modify the list have no return value printed -- they return the "
"default ``None``. [#]_ This is a design principle for all mutable data "
"structures in Python."
msgstr ""
#: ../../tutorial/datastructures.rst:126
msgid ""
"Another thing you might notice is that not all data can be sorted or "
"compared. For instance, ``[None, 'hello', 10]`` doesn't sort because "
"integers can't be compared to strings and ``None`` can't be compared to "
"other types. Also, there are some types that don't have a defined ordering "
"relation. For example, ``3+4j < 5+7j`` isn't a valid comparison."
msgstr ""
#: ../../tutorial/datastructures.rst:137
msgid "Using Lists as Stacks"
msgstr ""
#: ../../tutorial/datastructures.rst:142
msgid ""
"The list methods make it very easy to use a list as a stack, where the last "
"element added is the first element retrieved (\"last-in, first-out\"). To "
"add an item to the top of the stack, use :meth:`~list.append`. To retrieve "
"an item from the top of the stack, use :meth:`~list.pop` without an explicit "
"index. For example::"
msgstr ""
#: ../../tutorial/datastructures.rst:147
msgid ""
">>> stack = [3, 4, 5]\n"
">>> stack.append(6)\n"
">>> stack.append(7)\n"
">>> stack\n"
"[3, 4, 5, 6, 7]\n"
">>> stack.pop()\n"
"7\n"
">>> stack\n"
"[3, 4, 5, 6]\n"
">>> stack.pop()\n"
"6\n"
">>> stack.pop()\n"
"5\n"
">>> stack\n"
"[3, 4]"
msgstr ""
#: ../../tutorial/datastructures.rst:167
msgid "Using Lists as Queues"
msgstr ""
#: ../../tutorial/datastructures.rst:171
msgid ""
"It is also possible to use a list as a queue, where the first element added "
"is the first element retrieved (\"first-in, first-out\"); however, lists are "
"not efficient for this purpose. While appends and pops from the end of list "
"are fast, doing inserts or pops from the beginning of a list is slow "
"(because all of the other elements have to be shifted by one)."
msgstr ""
#: ../../tutorial/datastructures.rst:177
msgid ""
"To implement a queue, use :class:`collections.deque` which was designed to "
"have fast appends and pops from both ends. For example::"
msgstr ""
#: ../../tutorial/datastructures.rst:180
msgid ""
">>> from collections import deque\n"
">>> queue = deque([\"Eric\", \"John\", \"Michael\"])\n"
">>> queue.append(\"Terry\") # Terry arrives\n"
">>> queue.append(\"Graham\") # Graham arrives\n"
">>> queue.popleft() # The first to arrive now leaves\n"
"'Eric'\n"
">>> queue.popleft() # The second to arrive now leaves\n"
"'John'\n"
">>> queue # Remaining queue in order of arrival\n"
"deque(['Michael', 'Terry', 'Graham'])"
msgstr ""
#: ../../tutorial/datastructures.rst:195
msgid "List Comprehensions"
msgstr ""
#: ../../tutorial/datastructures.rst:197
msgid ""
"List comprehensions provide a concise way to create lists. Common "
"applications are to make new lists where each element is the result of some "
"operations applied to each member of another sequence or iterable, or to "
"create a subsequence of those elements that satisfy a certain condition."
msgstr ""
#: ../../tutorial/datastructures.rst:202
msgid "For example, assume we want to create a list of squares, like::"
msgstr ""
#: ../../tutorial/datastructures.rst:204
msgid ""
">>> squares = []\n"
">>> for x in range(10):\n"
"... squares.append(x**2)\n"
"...\n"
">>> squares\n"
"[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]"
msgstr ""
#: ../../tutorial/datastructures.rst:211
msgid ""
"Note that this creates (or overwrites) a variable named ``x`` that still "
"exists after the loop completes. We can calculate the list of squares "
"without any side effects using::"
msgstr ""
#: ../../tutorial/datastructures.rst:215
msgid "squares = list(map(lambda x: x**2, range(10)))"
msgstr ""
#: ../../tutorial/datastructures.rst:217
msgid "or, equivalently::"
msgstr ""
#: ../../tutorial/datastructures.rst:219
msgid "squares = [x**2 for x in range(10)]"
msgstr ""
#: ../../tutorial/datastructures.rst:221
msgid "which is more concise and readable."
msgstr ""
#: ../../tutorial/datastructures.rst:223
msgid ""
"A list comprehension consists of brackets containing an expression followed "
"by a :keyword:`!for` clause, then zero or more :keyword:`!for` or :keyword:`!"
"if` clauses. The result will be a new list resulting from evaluating the "
"expression in the context of the :keyword:`!for` and :keyword:`!if` clauses "
"which follow it. For example, this listcomp combines the elements of two "
"lists if they are not equal::"
msgstr ""
#: ../../tutorial/datastructures.rst:230
msgid ""
">>> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]\n"
"[(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)]"
msgstr ""
#: ../../tutorial/datastructures.rst:233
msgid "and it's equivalent to::"
msgstr ""
#: ../../tutorial/datastructures.rst:235
msgid ""
">>> combs = []\n"
">>> for x in [1,2,3]:\n"
"... for y in [3,1,4]:\n"
"... if x != y:\n"
"... combs.append((x, y))\n"
"...\n"
">>> combs\n"
"[(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)]"
msgstr ""
#: ../../tutorial/datastructures.rst:244
msgid ""
"Note how the order of the :keyword:`for` and :keyword:`if` statements is the "
"same in both these snippets."
msgstr ""
#: ../../tutorial/datastructures.rst:247
msgid ""
"If the expression is a tuple (e.g. the ``(x, y)`` in the previous example), "
"it must be parenthesized. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:250
msgid ""
">>> vec = [-4, -2, 0, 2, 4]\n"
">>> # create a new list with the values doubled\n"
">>> [x*2 for x in vec]\n"
"[-8, -4, 0, 4, 8]\n"
">>> # filter the list to exclude negative numbers\n"
">>> [x for x in vec if x >= 0]\n"
"[0, 2, 4]\n"
">>> # apply a function to all the elements\n"
">>> [abs(x) for x in vec]\n"
"[4, 2, 0, 2, 4]\n"
">>> # call a method on each element\n"
">>> freshfruit = [' banana', ' loganberry ', 'passion fruit ']\n"
">>> [weapon.strip() for weapon in freshfruit]\n"
"['banana', 'loganberry', 'passion fruit']\n"
">>> # create a list of 2-tuples like (number, square)\n"
">>> [(x, x**2) for x in range(6)]\n"
"[(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25)]\n"
">>> # the tuple must be parenthesized, otherwise an error is raised\n"
">>> [x, x**2 for x in range(6)]\n"
" File \"<stdin>\", line 1\n"
" [x, x**2 for x in range(6)]\n"
" ^^^^^^^\n"
"SyntaxError: did you forget parentheses around the comprehension target?\n"
">>> # flatten a list using a listcomp with two 'for'\n"
">>> vec = [[1,2,3], [4,5,6], [7,8,9]]\n"
">>> [num for elem in vec for num in elem]\n"
"[1, 2, 3, 4, 5, 6, 7, 8, 9]"
msgstr ""
#: ../../tutorial/datastructures.rst:278
msgid ""
"List comprehensions can contain complex expressions and nested functions::"
msgstr ""
#: ../../tutorial/datastructures.rst:280
msgid ""
">>> from math import pi\n"
">>> [str(round(pi, i)) for i in range(1, 6)]\n"
"['3.1', '3.14', '3.142', '3.1416', '3.14159']"
msgstr ""
#: ../../tutorial/datastructures.rst:285
msgid "Nested List Comprehensions"
msgstr ""
#: ../../tutorial/datastructures.rst:287
msgid ""
"The initial expression in a list comprehension can be any arbitrary "
"expression, including another list comprehension."
msgstr ""
#: ../../tutorial/datastructures.rst:290
msgid ""
"Consider the following example of a 3x4 matrix implemented as a list of 3 "
"lists of length 4::"
msgstr ""
#: ../../tutorial/datastructures.rst:293
msgid ""
">>> matrix = [\n"
"... [1, 2, 3, 4],\n"
"... [5, 6, 7, 8],\n"
"... [9, 10, 11, 12],\n"
"... ]"
msgstr ""
#: ../../tutorial/datastructures.rst:299
msgid "The following list comprehension will transpose rows and columns::"
msgstr ""
#: ../../tutorial/datastructures.rst:301
msgid ""
">>> [[row[i] for row in matrix] for i in range(4)]\n"
"[[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]"
msgstr ""
#: ../../tutorial/datastructures.rst:304
msgid ""
"As we saw in the previous section, the inner list comprehension is evaluated "
"in the context of the :keyword:`for` that follows it, so this example is "
"equivalent to::"
msgstr ""
#: ../../tutorial/datastructures.rst:308
msgid ""
">>> transposed = []\n"
">>> for i in range(4):\n"
"... transposed.append([row[i] for row in matrix])\n"
"...\n"
">>> transposed\n"
"[[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]"
msgstr ""
#: ../../tutorial/datastructures.rst:315
msgid "which, in turn, is the same as::"
msgstr ""
#: ../../tutorial/datastructures.rst:317
msgid ""
">>> transposed = []\n"
">>> for i in range(4):\n"
"... # the following 3 lines implement the nested listcomp\n"
"... transposed_row = []\n"
"... for row in matrix:\n"
"... transposed_row.append(row[i])\n"
"... transposed.append(transposed_row)\n"
"...\n"
">>> transposed\n"
"[[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]"
msgstr ""
#: ../../tutorial/datastructures.rst:328
msgid ""
"In the real world, you should prefer built-in functions to complex flow "
"statements. The :func:`zip` function would do a great job for this use case::"
msgstr ""
#: ../../tutorial/datastructures.rst:331
msgid ""
">>> list(zip(*matrix))\n"
"[(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]"
msgstr ""
#: ../../tutorial/datastructures.rst:334
msgid ""
"See :ref:`tut-unpacking-arguments` for details on the asterisk in this line."
msgstr ""
#: ../../tutorial/datastructures.rst:339
msgid "The :keyword:`!del` statement"
msgstr ""
#: ../../tutorial/datastructures.rst:341
msgid ""
"There is a way to remove an item from a list given its index instead of its "
"value: the :keyword:`del` statement. This differs from "
"the :meth:`~list.pop` method which returns a value. The :keyword:`!del` "
"statement can also be used to remove slices from a list or clear the entire "
"list (which we did earlier by assignment of an empty list to the slice). "
"For example::"
msgstr ""
#: ../../tutorial/datastructures.rst:347
msgid ""
">>> a = [-1, 1, 66.25, 333, 333, 1234.5]\n"
">>> del a[0]\n"
">>> a\n"
"[1, 66.25, 333, 333, 1234.5]\n"
">>> del a[2:4]\n"
">>> a\n"
"[1, 66.25, 1234.5]\n"
">>> del a[:]\n"
">>> a\n"
"[]"
msgstr ""
#: ../../tutorial/datastructures.rst:358
msgid ":keyword:`del` can also be used to delete entire variables::"
msgstr ""
#: ../../tutorial/datastructures.rst:360
msgid ">>> del a"
msgstr ""
#: ../../tutorial/datastructures.rst:362
msgid ""
"Referencing the name ``a`` hereafter is an error (at least until another "
"value is assigned to it). We'll find other uses for :keyword:`del` later."
msgstr ""
#: ../../tutorial/datastructures.rst:369
msgid "Tuples and Sequences"
msgstr ""
#: ../../tutorial/datastructures.rst:371
msgid ""
"We saw that lists and strings have many common properties, such as indexing "
"and slicing operations. They are two examples of *sequence* data types "
"(see :ref:`typesseq`). Since Python is an evolving language, other sequence "
"data types may be added. There is also another standard sequence data type: "
"the *tuple*."
msgstr ""
#: ../../tutorial/datastructures.rst:377
msgid ""
"A tuple consists of a number of values separated by commas, for instance::"
msgstr ""
#: ../../tutorial/datastructures.rst:379
msgid ""
">>> t = 12345, 54321, 'hello!'\n"
">>> t[0]\n"
"12345\n"
">>> t\n"
"(12345, 54321, 'hello!')\n"
">>> # Tuples may be nested:\n"
">>> u = t, (1, 2, 3, 4, 5)\n"
">>> u\n"
"((12345, 54321, 'hello!'), (1, 2, 3, 4, 5))\n"
">>> # Tuples are immutable:\n"
">>> t[0] = 88888\n"
"Traceback (most recent call last):\n"
" File \"<stdin>\", line 1, in <module>\n"
"TypeError: 'tuple' object does not support item assignment\n"
">>> # but they can contain mutable objects:\n"
">>> v = ([1, 2, 3], [3, 2, 1])\n"
">>> v\n"
"([1, 2, 3], [3, 2, 1])"
msgstr ""
#: ../../tutorial/datastructures.rst:399
msgid ""
"As you see, on output tuples are always enclosed in parentheses, so that "
"nested tuples are interpreted correctly; they may be input with or without "
"surrounding parentheses, although often parentheses are necessary anyway (if "
"the tuple is part of a larger expression). It is not possible to assign to "
"the individual items of a tuple, however it is possible to create tuples "
"which contain mutable objects, such as lists."
msgstr ""
#: ../../tutorial/datastructures.rst:406
msgid ""
"Though tuples may seem similar to lists, they are often used in different "
"situations and for different purposes. Tuples are :term:`immutable`, and "
"usually contain a heterogeneous sequence of elements that are accessed via "
"unpacking (see later in this section) or indexing (or even by attribute in "
"the case of :func:`namedtuples <collections.namedtuple>`). Lists "
"are :term:`mutable`, and their elements are usually homogeneous and are "
"accessed by iterating over the list."
msgstr ""
#: ../../tutorial/datastructures.rst:414
msgid ""
"A special problem is the construction of tuples containing 0 or 1 items: the "
"syntax has some extra quirks to accommodate these. Empty tuples are "
"constructed by an empty pair of parentheses; a tuple with one item is "
"constructed by following a value with a comma (it is not sufficient to "
"enclose a single value in parentheses). Ugly, but effective. For example::"
msgstr ""
#: ../../tutorial/datastructures.rst:420
msgid ""
">>> empty = ()\n"
">>> singleton = 'hello', # <-- note trailing comma\n"
">>> len(empty)\n"
"0\n"
">>> len(singleton)\n"
"1\n"
">>> singleton\n"
"('hello',)"
msgstr ""
#: ../../tutorial/datastructures.rst:429
msgid ""
"The statement ``t = 12345, 54321, 'hello!'`` is an example of *tuple "
"packing*: the values ``12345``, ``54321`` and ``'hello!'`` are packed "
"together in a tuple. The reverse operation is also possible::"
msgstr ""
#: ../../tutorial/datastructures.rst:433
msgid ">>> x, y, z = t"
msgstr ""
#: ../../tutorial/datastructures.rst:435
msgid ""
"This is called, appropriately enough, *sequence unpacking* and works for any "
"sequence on the right-hand side. Sequence unpacking requires that there are "
"as many variables on the left side of the equals sign as there are elements "
"in the sequence. Note that multiple assignment is really just a combination "
"of tuple packing and sequence unpacking."
msgstr ""
#: ../../tutorial/datastructures.rst:445
msgid "Sets"
msgstr ""
#: ../../tutorial/datastructures.rst:447
msgid ""
"Python also includes a data type for :ref:`sets <types-set>`. A set is an "
"unordered collection with no duplicate elements. Basic uses include "
"membership testing and eliminating duplicate entries. Set objects also "
"support mathematical operations like union, intersection, difference, and "
"symmetric difference."
msgstr ""
#: ../../tutorial/datastructures.rst:453
msgid ""
"Curly braces or the :func:`set` function can be used to create sets. Note: "
"to create an empty set you have to use ``set()``, not ``{}``; the latter "
"creates an empty dictionary, a data structure that we discuss in the next "
"section."
msgstr ""
#: ../../tutorial/datastructures.rst:457
msgid ""
"Because sets are unordered, iterating over them or printing them can produce "
"the elements in a different order than you expect."
msgstr ""
#: ../../tutorial/datastructures.rst:460
msgid "Here is a brief demonstration::"
msgstr ""
#: ../../tutorial/datastructures.rst:462
msgid ""
">>> basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}\n"
">>> print(basket) # show that duplicates have been "
"removed\n"
"{'orange', 'banana', 'pear', 'apple'}\n"
">>> 'orange' in basket # fast membership testing\n"
"True\n"
">>> 'crabgrass' in basket\n"
"False\n"
"\n"
">>> # Demonstrate set operations on unique letters from two words\n"
">>>\n"
">>> a = set('abracadabra')\n"
">>> b = set('alacazam')\n"
">>> a # unique letters in a\n"
"{'a', 'r', 'b', 'c', 'd'}\n"
">>> a - b # letters in a but not in b\n"
"{'r', 'd', 'b'}\n"
">>> a | b # letters in a or b or both\n"
"{'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'}\n"
">>> a & b # letters in both a and b\n"
"{'a', 'c'}\n"
">>> a ^ b # letters in a or b but not both\n"
"{'r', 'd', 'b', 'm', 'z', 'l'}"
msgstr ""
#: ../../tutorial/datastructures.rst:485
msgid ""
"Similarly to :ref:`list comprehensions <tut-listcomps>`, set comprehensions "
"are also supported::"
msgstr ""
#: ../../tutorial/datastructures.rst:488
msgid ""
">>> a = {x for x in 'abracadabra' if x not in 'abc'}\n"
">>> a\n"
"{'r', 'd'}"
msgstr ""
#: ../../tutorial/datastructures.rst:496
msgid "Dictionaries"
msgstr ""
#: ../../tutorial/datastructures.rst:498
msgid ""
"Another useful data type built into Python is the *dictionary* "
"(see :ref:`typesmapping`). Dictionaries are sometimes found in other "
"languages as \"associative memories\" or \"associative arrays\". Unlike "
"sequences, which are indexed by a range of numbers, dictionaries are indexed "
"by *keys*, which can be any immutable type; strings and numbers can always "
"be keys. Tuples can be used as keys if they contain only strings, numbers, "
"or tuples; if a tuple contains any mutable object either directly or "
"indirectly, it cannot be used as a key. You can't use lists as keys, since "
"lists can be modified in place using index assignments, slice assignments, "
"or methods like :meth:`~list.append` and :meth:`~list.extend`."
msgstr ""
#: ../../tutorial/datastructures.rst:509
msgid ""
"It is best to think of a dictionary as a set of *key: value* pairs, with the "
"requirement that the keys are unique (within one dictionary). A pair of "
"braces creates an empty dictionary: ``{}``. Placing a comma-separated list "
"of key:value pairs within the braces adds initial key:value pairs to the "
"dictionary; this is also the way dictionaries are written on output."
msgstr ""
#: ../../tutorial/datastructures.rst:515
msgid ""
"The main operations on a dictionary are storing a value with some key and "
"extracting the value given the key. It is also possible to delete a "
"key:value pair with ``del``. If you store using a key that is already in "
"use, the old value associated with that key is forgotten."
msgstr ""
#: ../../tutorial/datastructures.rst:520
msgid ""
"Extracting a value for a non-existent key by subscripting (``d[key]``) "
"raises a :exc:`KeyError`. To avoid getting this error when trying to access "
"a possibly non-existent key, use the :meth:`~dict.get` method instead, which "
"returns ``None`` (or a specified default value) if the key is not in the "
"dictionary."
msgstr ""
#: ../../tutorial/datastructures.rst:525
msgid ""
"Performing ``list(d)`` on a dictionary returns a list of all the keys used "
"in the dictionary, in insertion order (if you want it sorted, just use "
"``sorted(d)`` instead). To check whether a single key is in the dictionary, "
"use the :keyword:`in` keyword."
msgstr ""
#: ../../tutorial/datastructures.rst:530
msgid "Here is a small example using a dictionary::"
msgstr ""
#: ../../tutorial/datastructures.rst:532
msgid ""
">>> tel = {'jack': 4098, 'sape': 4139}\n"
">>> tel['guido'] = 4127\n"
">>> tel\n"
"{'jack': 4098, 'sape': 4139, 'guido': 4127}\n"
">>> tel['jack']\n"
"4098\n"
">>> tel['irv']\n"
"Traceback (most recent call last):\n"
" File \"<stdin>\", line 1, in <module>\n"
"KeyError: 'irv'\n"
">>> print(tel.get('irv'))\n"
"None\n"
">>> del tel['sape']\n"
">>> tel['irv'] = 4127\n"
">>> tel\n"
"{'jack': 4098, 'guido': 4127, 'irv': 4127}\n"
">>> list(tel)\n"
"['jack', 'guido', 'irv']\n"
">>> sorted(tel)\n"
"['guido', 'irv', 'jack']\n"
">>> 'guido' in tel\n"
"True\n"
">>> 'jack' not in tel\n"
"False"
msgstr ""
#: ../../tutorial/datastructures.rst:557
msgid ""
"The :func:`dict` constructor builds dictionaries directly from sequences of "
"key-value pairs::"
msgstr ""
#: ../../tutorial/datastructures.rst:560
msgid ""
">>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])\n"
"{'sape': 4139, 'guido': 4127, 'jack': 4098}"
msgstr ""
#: ../../tutorial/datastructures.rst:563
msgid ""
"In addition, dict comprehensions can be used to create dictionaries from "
"arbitrary key and value expressions::"
msgstr ""
#: ../../tutorial/datastructures.rst:566
msgid ""
">>> {x: x**2 for x in (2, 4, 6)}\n"
"{2: 4, 4: 16, 6: 36}"
msgstr ""
#: ../../tutorial/datastructures.rst:569
msgid ""
"When the keys are simple strings, it is sometimes easier to specify pairs "
"using keyword arguments::"
msgstr ""
#: ../../tutorial/datastructures.rst:572
msgid ""
">>> dict(sape=4139, guido=4127, jack=4098)\n"
"{'sape': 4139, 'guido': 4127, 'jack': 4098}"
msgstr ""
#: ../../tutorial/datastructures.rst:579
msgid "Looping Techniques"
msgstr ""
#: ../../tutorial/datastructures.rst:581
msgid ""
"When looping through dictionaries, the key and corresponding value can be "
"retrieved at the same time using the :meth:`~dict.items` method. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:584
msgid ""
">>> knights = {'gallahad': 'the pure', 'robin': 'the brave'}\n"
">>> for k, v in knights.items():\n"
"... print(k, v)\n"
"...\n"
"gallahad the pure\n"
"robin the brave"
msgstr ""
#: ../../tutorial/datastructures.rst:591
msgid ""
"When looping through a sequence, the position index and corresponding value "
"can be retrieved at the same time using the :func:`enumerate` function. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:594
msgid ""
">>> for i, v in enumerate(['tic', 'tac', 'toe']):\n"
"... print(i, v)\n"
"...\n"
"0 tic\n"
"1 tac\n"
"2 toe"
msgstr ""
#: ../../tutorial/datastructures.rst:601
msgid ""
"To loop over two or more sequences at the same time, the entries can be "
"paired with the :func:`zip` function. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:604
msgid ""
">>> questions = ['name', 'quest', 'favorite color']\n"
">>> answers = ['lancelot', 'the holy grail', 'blue']\n"
">>> for q, a in zip(questions, answers):\n"
"... print('What is your {0}? It is {1}.'.format(q, a))\n"
"...\n"
"What is your name? It is lancelot.\n"
"What is your quest? It is the holy grail.\n"
"What is your favorite color? It is blue."
msgstr ""
#: ../../tutorial/datastructures.rst:613
msgid ""
"To loop over a sequence in reverse, first specify the sequence in a forward "
"direction and then call the :func:`reversed` function. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:616
msgid ""
">>> for i in reversed(range(1, 10, 2)):\n"
"... print(i)\n"
"...\n"
"9\n"
"7\n"
"5\n"
"3\n"
"1"
msgstr ""
#: ../../tutorial/datastructures.rst:625
msgid ""
"To loop over a sequence in sorted order, use the :func:`sorted` function "
"which returns a new sorted list while leaving the source unaltered. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:628
msgid ""
">>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']\n"
">>> for i in sorted(basket):\n"
"... print(i)\n"
"...\n"
"apple\n"
"apple\n"
"banana\n"
"orange\n"
"orange\n"
"pear"
msgstr ""
#: ../../tutorial/datastructures.rst:639
msgid ""
"Using :func:`set` on a sequence eliminates duplicate elements. The use "
"of :func:`sorted` in combination with :func:`set` over a sequence is an "
"idiomatic way to loop over unique elements of the sequence in sorted "
"order. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:643
msgid ""
">>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']\n"
">>> for f in sorted(set(basket)):\n"
"... print(f)\n"
"...\n"
"apple\n"
"banana\n"
"orange\n"
"pear"
msgstr ""
#: ../../tutorial/datastructures.rst:652
msgid ""
"It is sometimes tempting to change a list while you are looping over it; "
"however, it is often simpler and safer to create a new list instead. ::"
msgstr ""
#: ../../tutorial/datastructures.rst:655
msgid ""
">>> import math\n"
">>> raw_data = [56.2, float('NaN'), 51.7, 55.3, 52.5, float('NaN'), 47.8]\n"
">>> filtered_data = []\n"
">>> for value in raw_data:\n"
"... if not math.isnan(value):\n"
"... filtered_data.append(value)\n"
"...\n"
">>> filtered_data\n"
"[56.2, 51.7, 55.3, 52.5, 47.8]"
msgstr ""
#: ../../tutorial/datastructures.rst:669
msgid "More on Conditions"
msgstr ""
#: ../../tutorial/datastructures.rst:671
msgid ""
"The conditions used in ``while`` and ``if`` statements can contain any "
"operators, not just comparisons."
msgstr ""
#: ../../tutorial/datastructures.rst:675
msgid ""
"The comparison operators ``in`` and ``not in`` are membership tests that "
"determine whether a value is in (or not in) a container. The operators "
"``is`` and ``is not`` compare whether two objects are really the same "
"object. All comparison operators have the same priority, which is lower "
"than that of all numerical operators."
msgstr ""
#: ../../tutorial/datastructures.rst:681
msgid ""
"Comparisons can be chained. For example, ``a < b == c`` tests whether ``a`` "
"is less than ``b`` and moreover ``b`` equals ``c``."
msgstr ""
#: ../../tutorial/datastructures.rst:684
msgid ""
"Comparisons may be combined using the Boolean operators ``and`` and ``or``, "
"and the outcome of a comparison (or of any other Boolean expression) may be "
"negated with ``not``. These have lower priorities than comparison "
"operators; between them, ``not`` has the highest priority and ``or`` the "
"lowest, so that ``A and not B or C`` is equivalent to ``(A and (not B)) or "
"C``. As always, parentheses can be used to express the desired composition."
msgstr ""
#: ../../tutorial/datastructures.rst:691
msgid ""
"The Boolean operators ``and`` and ``or`` are so-called *short-circuit* "
"operators: their arguments are evaluated from left to right, and evaluation "
"stops as soon as the outcome is determined. For example, if ``A`` and ``C`` "
"are true but ``B`` is false, ``A and B and C`` does not evaluate the "
"expression ``C``. When used as a general value and not as a Boolean, the "
"return value of a short-circuit operator is the last evaluated argument."
msgstr ""
#: ../../tutorial/datastructures.rst:698
msgid ""
"It is possible to assign the result of a comparison or other Boolean "
"expression to a variable. For example, ::"
msgstr ""
#: ../../tutorial/datastructures.rst:701
msgid ""
">>> string1, string2, string3 = '', 'Trondheim', 'Hammer Dance'\n"
">>> non_null = string1 or string2 or string3\n"
">>> non_null\n"
"'Trondheim'"
msgstr ""
#: ../../tutorial/datastructures.rst:706
msgid ""
"Note that in Python, unlike C, assignment inside expressions must be done "
"explicitly with the :ref:`walrus operator <why-can-t-i-use-an-assignment-in-"
"an-expression>` ``:=``. This avoids a common class of problems encountered "
"in C programs: typing ``=`` in an expression when ``==`` was intended."
msgstr ""
#: ../../tutorial/datastructures.rst:716
msgid "Comparing Sequences and Other Types"
msgstr ""
#: ../../tutorial/datastructures.rst:717
msgid ""
"Sequence objects typically may be compared to other objects with the same "
"sequence type. The comparison uses *lexicographical* ordering: first the "
"first two items are compared, and if they differ this determines the outcome "
"of the comparison; if they are equal, the next two items are compared, and "
"so on, until either sequence is exhausted. If two items to be compared are "
"themselves sequences of the same type, the lexicographical comparison is "
"carried out recursively. If all items of two sequences compare equal, the "
"sequences are considered equal. If one sequence is an initial sub-sequence "
"of the other, the shorter sequence is the smaller (lesser) one. "
"Lexicographical ordering for strings uses the Unicode code point number to "
"order individual characters. Some examples of comparisons between sequences "
"of the same type::"
msgstr ""
#: ../../tutorial/datastructures.rst:729
msgid ""
You can’t perform that action at this time.