# 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:
# python-doc bot, 2025
# Takanori Suzuki <takanori@takanory.net>, 2025
# Masahiro Ito, 2026
# Inada Naoki <songofacandy@gmail.com>, 2026
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: Python 3.15\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2026-10-23 18:01+0000\n"
"PO-Revision-Date: 2025-09-16 00:02+0000\n"
"Last-Translator: Inada Naoki <songofacandy@gmail.com>, 2026\n"
"Language-Team: Japanese (https://app.transifex.com/python-doc/teams/5390/"
"ja/)\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Language: ja\n"
"Plural-Forms: nplurals=1; plural=0;\n"

#: ../../tutorial/datastructures.rst:5
msgid "Data Structures"
msgstr "データ構造"

#: ../../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 ""
"この章では、すでに学んだことについてより詳しく説明するとともに、いくつか新し"
"いことを追加します。"

#: ../../tutorial/datastructures.rst:13
msgid "More on Lists"
msgstr "リスト型についてもう少し"

#: ../../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 ""
":ref:`list <typesseq-list>` 型には、他にもいくつかメソッドがあります。リスト"
"オブジェクトのすべてのメソッドを以下に示します:"

#: ../../tutorial/datastructures.rst:21
msgid "Add an item to the end of the list.  Similar to ``a[len(a):] = [x]``."
msgstr "リストの末尾に要素を一つ追加します。``a[len(a):] = [x]`` と同様です。"

msgid ""
"Extend the list by appending all the items from the iterable.  Similar to "
"``a[len(a):] = iterable``."
msgstr ""
"``iterable`` のすべての要素をリストの末尾に追加します。\n"
"``a[len(a):] = iterable`` と同様です。"

#: ../../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 ""
"指定した位置に要素を挿入します。第 1 引数は、リストのインデクスで、そのインデ"
"クスを持つ要素の直前に挿入が行われます。従って、 ``a.insert(0, x)`` はリスト"
"の先頭に挿入を行います。また ``a.insert(len(a), x)`` は ``a.append(x)`` と等"
"価です。"

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 ""
"*value* と等しい値を持つ最初の要素をリストから削除します。該当する要素がなけ"
"れば :exc:`ValueError` を送出します。"

#: ../../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 ""
"指定された位置の要素をリストから取り除き、それを返します。インデックスが指定"
"されていない場合、 ``a.pop()`` はリスト末尾の要素を取り除いて返します。リスト"
"が空であるか、インデックスがリストの範囲外の場合は、:exc:`IndexError` を送出"
"します。"

#: ../../tutorial/datastructures.rst:58
msgid "Remove all items from the list.  Similar to ``del a[:]``."
msgstr "リスト中の全ての要素を削除します。``del a[:]`` と同様です。"

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 ""
"リスト内で *value* が最初に現れる位置のインデックスを返します。インデックス"
"は 0 から数えます。該当する要素がなければ :exc:`ValueError` を送出します。"

#: ../../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 ""
"任意の引数である *start* と *end* はスライス記法として解釈され、リストの探索"
"範囲を指定できます。返される添字は、*start* 引数からの相対位置ではなく、リス"
"ト全体の先頭からの位置になります。"

msgid "Return the number of times *value* appears in the list."
msgstr "*value* がリスト内に現れる回数を返します。"

#: ../../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 ""
"リストの項目を、インプレース演算 (in place、元のデータを演算結果で置き換える"
"やりかた) でソートします。引数はソート方法のカスタマイズに使えます。 :func:"
"`sorted` の説明を参照してください。"

#: ../../tutorial/datastructures.rst:89
msgid "Reverse the elements of the list in place."
msgstr "リストの要素を、インプレース演算で逆順にします。"

#: ../../tutorial/datastructures.rst:95
msgid "Return a shallow copy of the list.  Similar to ``a[:]``."
msgstr "リストの浅い (shallow) コピーを返します。``a[:]`` と同様です。"

#: ../../tutorial/datastructures.rst:98
msgid "An example that uses most of the list methods::"
msgstr "以下にリストのメソッドをほぼ全て使った例を示します::"

#: ../../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 ""
">>> 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)  # インデックス4から数えて次の banana の位置\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'"

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 ""
"``insert``、``remove``、``sort`` など、リストの変更だけを行うメソッドの戻り値"
"が表示されていないことに気が付いたかもしれません。\n"
"これらのメソッドはデフォルトの ``None`` を返しています。\n"
"[#]_ これは Python の変更可能なデータ構造全てについての設計上の原則となってい"
"ます。"

#: ../../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 ""
"もうひとつ気付くとしたら、すべてのデータでソートや比較できるわけではないとい"
"うことです。  例えば、 ``[None, 'hello', 10]`` はソートされません。なぜなら整"
"数は文字列と比べられませんし、 ``None`` は他の型と比べられないからです。  ま"
"た、順序関係が定義されていない型もあります。  例えば、 ``3+4j < 5+7j`` は有効"
"な比較ではありません。"

#: ../../tutorial/datastructures.rst:137
msgid "Using Lists as Stacks"
msgstr "リストをスタックとして使う"

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 ""
"リストのメソッドを使えば、リストを簡単にスタックとして使えます。スタックは最"
"後に追加した要素を最初に取り出す「後入れ先出し」の仕組みです。スタックの一番"
"上に要素を追加するには :meth:`~list.append` を使います。一番上から要素を取り"
"出すには、インデックスを指定せずに :meth:`~list.pop` を使います。例えば次のよ"
"うにします::"

#: ../../tutorial/datastructures.rst:144
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 ""
">>> 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]"

#: ../../tutorial/datastructures.rst:164
msgid "Using Lists as Queues"
msgstr "リストをキューとして使う"

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).  See :ref:"
"`time-complexity` for more information."
msgstr ""
"リストは最初に追加した要素を最初に取り出す「先入れ先出し」のキューとしても使"
"えますが、この用途では効率がよくありません。リストの末尾での追加や取り出しは"
"高速ですが、先頭での挿入や取り出しには時間がかかります。他のすべての要素を1つ"
"ずつずらす必要があるためです。詳しくは :ref:`time-complexity` を参照してくだ"
"さい。"

msgid ""
"To implement a queue, use :class:`collections.deque` which was designed to "
"have fast appends and pops from both ends.  For example::"
msgstr ""
"キューの実装には :class:`collections.deque` を使います。このクラスは両端で要"
"素を高速に追加・取り出しできるように設計されています。例えば次のように使いま"
"す::"

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 ""
">>> from collections import deque\n"
">>> queue = deque([\"Eric\", \"John\", \"Michael\"])\n"
">>> queue.append(\"Terry\")           # Terry が到着\n"
">>> queue.append(\"Graham\")          # Graham が到着\n"
">>> queue.popleft()                 # 最初に到着した人が去る\n"
"'Eric'\n"
">>> queue.popleft()                 # 2番目に到着した人が去る\n"
"'John'\n"
">>> queue                           # 残っている人を到着順に表示\n"
"deque(['Michael', 'Terry', 'Graham'])"

msgid "List Comprehensions"
msgstr "リスト内包表記"

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 ""
"リスト内包表記を使うとリストを簡潔に作れます。シーケンスやイテラブルの各要素"
"に操作を適用した結果から新しいリストを作るときによく使います。また、特定の条"
"件を満たす要素だけを取り出して部分シーケンスを作ることもできます。"

#: ../../tutorial/datastructures.rst:198
msgid "For example, assume we want to create a list of squares, like::"
msgstr "例えば、次のような平方のリストを作りたいとします::"

#: ../../tutorial/datastructures.rst:200
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 ""
">>> 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]"

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 ""
"このコードは ``x`` という名前の変数を作るか、既存の変数を上書きします。この変"
"数がループ終了後も残ることに注意してください。次のように書けば、副作用なしで"
"平方のリストを計算できます::"

#: ../../tutorial/datastructures.rst:211
msgid "squares = list(map(lambda x: x**2, range(10)))"
msgstr "squares = list(map(lambda x: x**2, range(10)))"

#: ../../tutorial/datastructures.rst:213
msgid "or, equivalently::"
msgstr "もしくは、以下でも同じです::"

#: ../../tutorial/datastructures.rst:215
msgid "squares = [x**2 for x in range(10)]"
msgstr "squares = [x**2 for x in range(10)]"

#: ../../tutorial/datastructures.rst:217
msgid "which is more concise and readable."
msgstr "これはより簡潔で読みやすいです。"

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 ""
"リスト内包表記は、式とそれに続く :keyword:`!for` 句、さらに0個以上の :"
"keyword:`!for` 句または :keyword:`!if` 句を角括弧で囲んだものです。式に続く :"
"keyword:`!for` 句と :keyword:`!if` 句に従って式を評価し、その結果を要素とする"
"新しいリストを作ります。例えば次のリスト内包表記は、2つのリストから等しくない"
"要素同士を組み合わせてペアを作ります::"

#: ../../tutorial/datastructures.rst:226
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 ""
">>> [(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)]"

#: ../../tutorial/datastructures.rst:229
msgid "and it's equivalent to::"
msgstr "これは次のコードと等価です::"

#: ../../tutorial/datastructures.rst:231
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 ""
">>> 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)]"

msgid ""
"Note how the order of the :keyword:`for` and :keyword:`if` statements is the "
"same in both these snippets."
msgstr ""
"どちらのコードでも :keyword:`for` 文と :keyword:`if` 文の順序が同じであること"
"に注目してください。"

msgid ""
"If the expression is a tuple (e.g. the ``(x, y)`` in the previous example), "
"it must be parenthesized. ::"
msgstr ""
"式がタプルの場合は前の例の ``(x, y)`` のように丸括弧で囲む必要があります。 ::"

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 ""
">>> vec = [-4, -2, 0, 2, 4]\n"
">>> # 値を2倍にした新しいリストを作る\n"
">>> [x*2 for x in vec]\n"
"[-8, -4, 0, 4, 8]\n"
">>> # リストから負の数を除く\n"
">>> [x for x in vec if x >= 0]\n"
"[0, 2, 4]\n"
">>> # すべての要素に関数を適用する\n"
">>> [abs(x) for x in vec]\n"
"[4, 2, 0, 2, 4]\n"
">>> # 各要素のメソッドを呼び出す\n"
">>> freshfruit = ['  banana', '  loganberry ', 'passion fruit  ']\n"
">>> [weapon.strip() for weapon in freshfruit]\n"
"['banana', 'loganberry', 'passion fruit']\n"
">>> # (number, square) のような2要素のタプルのリストを作る\n"
">>> [(x, x**2) for x in range(6)]\n"
"[(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25)]\n"
">>> # タプルを丸括弧で囲まないとエラーになる\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"
">>> # 2つの 'for' を持つリスト内包表記でリストをフラットにする\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]"

msgid ""
"List comprehensions can contain complex expressions and nested functions::"
msgstr "リスト内包表記では複雑な式や入れ子になった関数呼び出しも使えます::"

#: ../../tutorial/datastructures.rst:276
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 ""
">>> 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']"

#: ../../tutorial/datastructures.rst:281
msgid "Nested List Comprehensions"
msgstr "ネストしたリストの内包表記"

#: ../../tutorial/datastructures.rst:283
msgid ""
"The initial expression in a list comprehension can be any arbitrary "
"expression, including another list comprehension."
msgstr ""
"リスト内包表記中の最初の式は任意の式なので、そこに他のリスト内包表記を書くこ"
"ともできます。"

msgid ""
"Consider the following example of a 3x4 matrix implemented as a list of 3 "
"lists of length 4::"
msgstr ""
"長さ 4 のリスト 3 つからなるリストで実装した、次の 3x4 の行列について考えま"
"す。 ::"

#: ../../tutorial/datastructures.rst:289
msgid ""
">>> matrix = [\n"
"...     [1, 2, 3, 4],\n"
"...     [5, 6, 7, 8],\n"
"...     [9, 10, 11, 12],\n"
"... ]"
msgstr ""
">>> matrix = [\n"
"...     [1, 2, 3, 4],\n"
"...     [5, 6, 7, 8],\n"
"...     [9, 10, 11, 12],\n"
"... ]"

#: ../../tutorial/datastructures.rst:295
msgid "The following list comprehension will transpose rows and columns::"
msgstr "次のリスト内包表記は、matrix の行と列を入れ替えます::"

#: ../../tutorial/datastructures.rst:297
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 ""
">>> [[row[i] for row in matrix] for i in range(4)]\n"
"[[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]"

#: ../../tutorial/datastructures.rst:300
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 ""
"前の節で見たように、内側のリスト内包表記は、続く :keyword:`for` のコンテキス"
"トの中で評価されます。そのため、この例は次のコードと等価です::"

#: ../../tutorial/datastructures.rst:304
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 ""
">>> 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]]"

#: ../../tutorial/datastructures.rst:311
msgid "which, in turn, is the same as::"
msgstr "これをもう一度変換すると、次のコードと等価になります::"

#: ../../tutorial/datastructures.rst:313
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 ""
">>> transposed = []\n"
">>> for i in range(4):\n"
"...     # 以下の3行はネストされたリスト内包表記と同じ実装\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]]"

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 ""
"実際のコードでは、複雑な制御フローの文よりも組み込み関数を優先すべきです。\n"
"この用途には :func:`zip` 関数が適しています。 ::"

#: ../../tutorial/datastructures.rst:327
msgid ""
">>> list(zip(*matrix))\n"
"[(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]"
msgstr ""
">>> list(zip(*matrix))\n"
"[(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]"

#: ../../tutorial/datastructures.rst:330
msgid ""
"See :ref:`tut-unpacking-arguments` for details on the asterisk in this line."
msgstr ""
"この行にあるアスタリスクの詳細については :ref:`tut-unpacking-arguments` を参"
"照してください。"

msgid "Unpacking in Lists and List Comprehensions"
msgstr "リストとリスト内包表記でのアンパック"

msgid ""
"The section on :ref:`tut-unpacking-arguments` describes the use of ``*`` to "
"\"unpack\" the elements of an iterable object, providing each one separately "
"as an argument to a function.  Unpacking can also be used in other contexts, "
"for example, when creating lists.  When specifying elements of a list, "
"prefixing an expression by a ``*`` will unpack the result of that "
"expression, adding each of its elements to the list we're creating::"
msgstr ""
":ref:`tut-unpacking-arguments` の節では、``*`` を使ってイテラブルオブジェクト"
"の要素を「アンパック」し、それぞれを関数の実引数として個別に渡す方法を説明し"
"ています。\n"
"アンパックは、リストの作成など他の場面でも使えます。\n"
"リストの要素を指定するときに式の先頭に ``*`` を付けると、その式の結果がアン"
"パックされ、各要素が作成中のリストに追加されます。 ::"

msgid ""
">>> x = [1, 2, 3]\n"
">>> [0, *x, 4, 5, 6]\n"
"[0, 1, 2, 3, 4, 5, 6]"
msgstr ""
">>> x = [1, 2, 3]\n"
">>> [0, *x, 4, 5, 6]\n"
"[0, 1, 2, 3, 4, 5, 6]"

msgid ""
"This only works if the expression following the ``*`` evaluates to an "
"iterable object; trying to unpack a non-iterable object will raise an "
"exception::"
msgstr ""
"この方法を使えるのは、``*`` に続く式の評価結果がイテラブルオブジェクトになる"
"場合だけです。\n"
"イテラブルでないオブジェクトをアンパックしようとすると、例外が送出されま"
"す。 ::"

msgid ""
">>> x = 1\n"
">>> [0, *x, 2, 3, 4]\n"
"Traceback (most recent call last):\n"
"  File \"<python-input-1>\", line 1, in <module>\n"
"    [0, *x, 2, 3, 4]\n"
"TypeError: Value after * must be an iterable, not int"
msgstr ""
">>> x = 1\n"
">>> [0, *x, 2, 3, 4]\n"
"Traceback (most recent call last):\n"
"  File \"<python-input-1>\", line 1, in <module>\n"
"    [0, *x, 2, 3, 4]\n"
"TypeError: Value after * must be an iterable, not int"

msgid ""
"Unpacking can also be used in list comprehensions, as a way to build a new "
"list representing the concatenation of an arbitrary number of iterables::"
msgstr ""
"リスト内包表記でもアンパックを使えます。\n"
"これにより、任意の数のイテラブルを連結した新しいリストを作成できます。 ::"

msgid ""
">>> x = [[1, 2, 3], [4, 5, 6], [], [7], [8, 9]]\n"
">>> [*element for element in x]\n"
"[1, 2, 3, 4, 5, 6, 7, 8, 9]"
msgstr ""
">>> x = [[1, 2, 3], [4, 5, 6], [], [7], [8, 9]]\n"
">>> [*element for element in x]\n"
"[1, 2, 3, 4, 5, 6, 7, 8, 9]"

msgid ""
"Note that the effect is that each element from ``x`` is unpacked.  This "
"works for arbitrary iterable objects, not just lists::"
msgstr ""
"``x`` の各要素がアンパックされる点に注意してください。\n"
"これはリストだけでなく、任意のイテラブルオブジェクトで使えます。 ::"

msgid ""
">>> x = [[1, 2, 3], 'cat', {'spam': 'eggs'}]\n"
">>> [*element for element in x]\n"
"[1, 2, 3, 'c', 'a', 't', 'spam']"
msgstr ""
">>> x = [[1, 2, 3], 'cat', {'spam': 'eggs'}]\n"
">>> [*element for element in x]\n"
"[1, 2, 3, 'c', 'a', 't', 'spam']"

msgid ""
"But if the objects in ``x`` are not iterable, this expression would again "
"raise an exception."
msgstr ""
"ただし、``x`` の中のオブジェクトがイテラブルでなければ、この式でも例外が送出"
"されます。"

#: ../../tutorial/datastructures.rst:376
msgid "The :keyword:`!del` statement"
msgstr ":keyword:`!del` 文"

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 ""
"リストから要素を削除する際、値を指定する代わりにインデックスを指定する方法が"
"あります。\n"
"それが :keyword:`del` 文です。\n"
"これは :meth:`~list.pop` メソッドと違い、値を返しません。\n"
":keyword:`!del` 文はリストからスライスを除去したり、リストの全要素を削除する"
"こともできます(以前はスライスに空のリストを代入して行っていました)。\n"
"例えば以下のようにします。 ::"

#: ../../tutorial/datastructures.rst:384
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 ""
">>> 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"
"[]"

#: ../../tutorial/datastructures.rst:395
msgid ":keyword:`del` can also be used to delete entire variables::"
msgstr ":keyword:`del` は変数全体の削除にも使えます::"

#: ../../tutorial/datastructures.rst:397
msgid ">>> del a"
msgstr ">>> del a"

#: ../../tutorial/datastructures.rst:399
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 ""
"この文の後で名前 ``a`` を参照すると、(別の値を ``a`` に代入するまで) エラーに"
"なります。 :keyword:`del` の別の用途についてはまた後で取り上げます。"

#: ../../tutorial/datastructures.rst:406
msgid "Tuples and Sequences"
msgstr "タプルとシーケンス"

#: ../../tutorial/datastructures.rst:408
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 ""
"リストや文字列には、インデクスやスライスを使った演算のように、数多くの共通の"
"性質があることを見てきました。これらは *シーケンス (sequence)* データ型 (:"
"ref:`typesseq` を参照) の二つの例です。 Python はまだ進歩の過程にある言語なの"
"で、他のシーケンスデータ型が追加されるかもしれません。標準のシーケンス型はも"
"う一つあります: *タプル (tuple)* 型です。"

#: ../../tutorial/datastructures.rst:414
msgid ""
"A tuple consists of a number of values separated by commas, for instance::"
msgstr ""
"タプルはコンマで区切られたいくつかの値からなります。例えば以下のように書きま"
"す::"

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])\n"
">>> # they support unpacking just like lists:\n"
">>> x = [1, 2, 3]\n"
">>> 0, *x, 4\n"
"(0, 1, 2, 3, 4)"
msgstr ""
">>> t = 12345, 54321, 'hello!'\n"
">>> t[0]\n"
"12345\n"
">>> t\n"
"(12345, 54321, 'hello!')\n"
">>> # タプルはネストできる:\n"
">>> u = t, (1, 2, 3, 4, 5)\n"
">>> u\n"
"((12345, 54321, 'hello!'), (1, 2, 3, 4, 5))\n"
">>> # タプルは不変:\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"
">>> # ただし、可変オブジェクトを含めることはできる:\n"
">>> v = ([1, 2, 3], [3, 2, 1])\n"
">>> v\n"
"([1, 2, 3], [3, 2, 1])\n"
">>> # リストと同様にアンパックもサポートする:\n"
">>> x = [1, 2, 3]\n"
">>> 0, *x, 4\n"
"(0, 1, 2, 3, 4)"

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 ""
"ご覧のとおり、タプルの表示には常に丸括弧がついていて、タプルのネストが正しく"
"解釈されるようになっています。\n"
"タプルを書くときは必ずしも丸括弧で囲まなくてもいいですが、(タプルが大きな式の"
"一部だった場合は) 丸括弧が必要な場合もあります。\n"
"タプルの各要素に代入することはできません。\n"
"しかし、タプルにリストのような変更可能なオブジェクトを含めることはできます。"

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 ""
"タプルはリストと似て見えますが、使う場面や目的は異なることが多いです。\n"
"タプルは :term:`不変 <immutable>` で、通常は異なる型の要素が並びます。\n"
"要素には、アンパック (この節の後半で説明します) やインデックスを使ってアクセ"
"スします (:func:`namedtuples <collections.namedtuple>` では属性でもアクセスで"
"きます)。\n"
"リストは :term:`可変 <mutable>` で、要素は通常同じ型であり、リストを反復処理"
"してアクセスします。"

#: ../../tutorial/datastructures.rst:454
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 ""
"問題は 0 個または 1 個の項目からなるタプルの構築です。これらの操作を行うた"
"め、構文には特別な細工がされています。空のタプルは空の丸括弧ペアで構築できま"
"す。一つの要素を持つタプルは、値の後ろにコンマを続ける (単一の値を丸括弧で囲"
"むだけでは不十分です) ことで構築できます。美しくはないけれども、効果的です。"
"例えば以下のようにします::"

#: ../../tutorial/datastructures.rst:460
msgid ""
">>> empty = ()\n"
">>> singleton = 'hello',    # <-- note trailing comma\n"
">>> len(empty)\n"
"0\n"
">>> len(singleton)\n"
"1\n"
">>> singleton\n"
"('hello',)"
msgstr ""
">>> empty = ()\n"
">>> singleton = 'hello',    # <-- 末尾にカンマがあることに注意\n"
">>> len(empty)\n"
"0\n"
">>> len(singleton)\n"
"1\n"
">>> singleton\n"
"('hello',)"

#: ../../tutorial/datastructures.rst:469
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 ""
"文 ``t = 12345, 54321, 'hello!'`` は *タプルのパック (tuple packing)* の例で"
"す。値 ``12345``, ``54321``, ``'hello!'`` が一つのタプルにパックされます。逆"
"の演算も可能です::"

#: ../../tutorial/datastructures.rst:473
msgid ">>> x, y, z = t"
msgstr ">>> x, y, z = t"

#: ../../tutorial/datastructures.rst:475
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 ""
"この操作は、*シーケンスのアンパック (sequence unpacking)* とでも呼ぶべきもの"
"で、右辺には全てのシーケンス型を使うことができます。シーケンスのアンパックで"
"は、等号の左辺に列挙されている変数が、右辺のシーケンスの長さと同じ数だけある"
"ことが要求されます。複数同時の代入が実はタプルのパックとシーケンスのアンパッ"
"クを組み合わせたものに過ぎないことに注意してください。"

#: ../../tutorial/datastructures.rst:485
msgid "Sets"
msgstr "集合型"

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 ""
"Python には、 :ref:`sets <types-set>` を扱うためのデータ型もあります。\n"
"集合とは、重複する要素をもたない、順序づけられていない要素の集まりです。\n"
"基本的な用途には、要素が含まれるかどうかの判定や、重複する要素の除去がありま"
"す。\n"
"``set`` オブジェクトは、和 (union)、積 (intersection)、差 (difference)、\n"
"対称差 (symmetric difference)といった数学的な演算もサポートしています。"

#: ../../tutorial/datastructures.rst:493
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 ""
"中括弧、または :func:`set` 関数は set を生成するために使用することができま"
"す。注: 空集合を作成するためには ``set()`` を使用しなければなりません (``{}"
"`` ではなく)。後者は空の辞書を作成します。辞書は次のセクションで議論するデー"
"タ構造です。"

msgid ""
"Because sets are unordered, iterating over them or printing them can produce "
"the elements in a different order than you expect."
msgstr ""
"集合には順序がないため、反復処理したり表示したりすると、要素が予想とは異なる"
"順序で現れることがあります。"

#: ../../tutorial/datastructures.rst:500
msgid "Here is a brief demonstration::"
msgstr "簡単なデモンストレーションを示します::"

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 ""
">>> basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}\n"
">>> print(basket)                      # 重複が削除されていることを確認\n"
"{'orange', 'banana', 'pear', 'apple'}\n"
">>> 'orange' in basket                 # 高速なメンバー判定\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                                  # aのユニークな文字\n"
"{'a', 'r', 'b', 'c', 'd'}\n"
">>> a - b                              # aにあってbにない文字\n"
"{'r', 'd', 'b'}\n"
">>> a | b                              # aまたはbまたは両方に存在する文字\n"
"{'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'}\n"
">>> a & b                              # aとbの両方に存在する文字\n"
"{'a', 'c'}\n"
">>> a ^ b                              # aまたはbにあるが、両方にはない文字\n"
"{'r', 'd', 'b', 'm', 'z', 'l'}"

msgid ""
"Similarly to :ref:`list comprehensions <tut-listcomps>`, set comprehensions "
"are also supported, including comprehensions with unpacking::"
msgstr ""
":ref:`リスト内包表記 <tut-listcomps>` と同様に、集合内包表記もサポートされて"
"おり、アンパックを使う内包表記も書けます。 ::"

msgid ""
">>> a = {x for x in 'abracadabra' if x not in 'abc'}\n"
">>> a\n"
"{'r', 'd'}\n"
"\n"
">>> fruits = [{'apple', 'avocado', 'apricot'}, {'banana', 'blueberry'}]\n"
">>> {*fruit for fruit in fruits}\n"
"{'blueberry', 'banana', 'avocado', 'apple', 'apricot'}"
msgstr ""
">>> a = {x for x in 'abracadabra' if x not in 'abc'}\n"
">>> a\n"
"{'r', 'd'}\n"
"\n"
">>> fruits = [{'apple', 'avocado', 'apricot'}, {'banana', 'blueberry'}]\n"
">>> {*fruit for fruit in fruits}\n"
"{'blueberry', 'banana', 'avocado', 'apple', 'apricot'}"

#: ../../tutorial/datastructures.rst:540
msgid "Dictionaries"
msgstr "辞書型 (dictionary)"

#: ../../tutorial/datastructures.rst:542
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 ""
"もう一つ、有用な型が Python に組み込まれています。それは *辞書 (dictionary)* "
"(:ref:`typesmapping` を参照)です。辞書は他の言語にも \"連想記憶 (associated "
"memory)\" や \"連想配列 (associative array)\" という名前で存在することがあり"
"ます。ある範囲の数でインデックス化されているシーケンスと異なり、辞書は *キー "
"(key)* でインデックス化されています。このキーは何らかの変更不能な型になりま"
"す。文字列、数値は常にキーにすることができます。タプルは、文字列、数値、その"
"他のタプルのみを含む場合はキーにすることができます。直接、あるいは間接的に変"
"更可能なオブジェクトを含むタプルはキーにできません。リストをキーとして使うこ"
"とはできません。これは、リストにスライスやインデックス指定の代入を行った"
"り、 :meth:`~list.append` や :meth:`~list.extend` のようなメソッドを使うと、"
"インプレースで変更することができるためです。"

#: ../../tutorial/datastructures.rst:553
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 ""
"辞書は *キー(key): 値(value)* のペアの集合であり、キーが (辞書の中で)一意でな"
"ければならない、と考えるとよいでしょう。波括弧 (brace) のペア: ``{}`` は空の"
"辞書を生成します。カンマで区切られた key: value のペアを波括弧ペアの間に入れ"
"ると、辞書の初期値となる key: value が追加されます; この表現方法は出力時に辞"
"書が書き出されるのと同じ方法です。"

#: ../../tutorial/datastructures.rst:559
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 ""
"辞書での主な操作は、ある値を何らかのキーを付けて記憶することと、キーを指定し"
"て値を取り出すことです。 ``del`` で key: value のペアを削除することもできま"
"す。すでに使われているキーを使って値を記憶すると、以前そのキーに関連づけられ"
"ていた値は忘れ去られてしまいます。"

#: ../../tutorial/datastructures.rst:564
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 ""
"存在しないキーの値をインデックス指定(``d[key]``)で取り出すと :exc:`KeyError` "
"が発生します。存在しない可能性のあるキーへのアクセス時にこのエラーを回避する"
"には、代わりに :meth:`~dict.get` メソッドを使用します。このメソッドは辞書に"
"キーが存在しない場合に ``None`` (または指定されたデフォルト値)を返します。"

#: ../../tutorial/datastructures.rst:569
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 ""
"辞書オブジェクトに対し ``list(d)`` を実行すると、辞書で使われている全てのキー"
"からなるリストをキーが挿入された順番で返します (ソートされたリストが欲しい場"
"合は、代わりに ``sorted(d)`` を使ってください)。ある単一のキーが辞書にあるか"
"どうか調べるには、 :keyword:`in` キーワードを使います。"

#: ../../tutorial/datastructures.rst:574
msgid "Here is a small example using a dictionary::"
msgstr "以下に、辞書を使った簡単な例を示します::"

#: ../../tutorial/datastructures.rst:576
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 ""
">>> 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"

msgid ""
"The :func:`dict` constructor builds dictionaries directly from sequences of "
"key-value pairs::"
msgstr ""
":func:`dict` コンストラクタは、キーと値のペアからなるシーケンスから直接辞書を"
"生成します。 ::"

#: ../../tutorial/datastructures.rst:604
msgid ""
">>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])\n"
"{'sape': 4139, 'guido': 4127, 'jack': 4098}"
msgstr ""
">>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])\n"
"{'sape': 4139, 'guido': 4127, 'jack': 4098}"

msgid ""
"In addition, dict comprehensions can be used to create dictionaries from "
"arbitrary key and value expressions::"
msgstr "さらに、辞書内包表記ではキーと値に任意の式を使って辞書を作れます。 ::"

#: ../../tutorial/datastructures.rst:610
msgid ""
">>> {x: x**2 for x in (2, 4, 6)}\n"
"{2: 4, 4: 16, 6: 36}"
msgstr ""
">>> {x: x**2 for x in (2, 4, 6)}\n"
"{2: 4, 4: 16, 6: 36}"

msgid ""
"And dictionary unpacking (via ``**``) can be used to merge multiple "
"dictionaries::"
msgstr ""
"また、辞書のアンパック (``**`` を使います) によって、複数の辞書を結合できま"
"す。 ::"

msgid ""
">>> odds = {i: i**2 for i in (1, 3, 5)}\n"
">>> evens = {i: i**2 for i in (2, 4, 6)}\n"
">>> {**odds, **evens}\n"
"{1: 1, 3: 9, 5: 25, 2: 4, 4: 16, 6: 36}\n"
"\n"
">>> all_values = [odds, evens, {0: 0}]\n"
">>> {**i for i in all_values}\n"
"{1: 1, 3: 9, 5: 25, 2: 4, 4: 16, 6: 36, 0: 0}"
msgstr ""
">>> odds = {i: i**2 for i in (1, 3, 5)}\n"
">>> evens = {i: i**2 for i in (2, 4, 6)}\n"
">>> {**odds, **evens}\n"
"{1: 1, 3: 9, 5: 25, 2: 4, 4: 16, 6: 36}\n"
"\n"
">>> all_values = [odds, evens, {0: 0}]\n"
">>> {**i for i in all_values}\n"
"{1: 1, 3: 9, 5: 25, 2: 4, 4: 16, 6: 36, 0: 0}"

#: ../../tutorial/datastructures.rst:625
msgid ""
"When the keys are simple strings, it is sometimes easier to specify pairs "
"using keyword arguments::"
msgstr ""
"キーが単純な文字列の場合、キーワード引数を使って定義する方が単純な場合もあり"
"ます::"

#: ../../tutorial/datastructures.rst:628
msgid ""
">>> dict(sape=4139, guido=4127, jack=4098)\n"
"{'sape': 4139, 'guido': 4127, 'jack': 4098}"
msgstr ""
">>> dict(sape=4139, guido=4127, jack=4098)\n"
"{'sape': 4139, 'guido': 4127, 'jack': 4098}"

#: ../../tutorial/datastructures.rst:635
msgid "Looping Techniques"
msgstr "ループのテクニック"

#: ../../tutorial/datastructures.rst:637
msgid ""
"When looping through dictionaries, the key and corresponding value can be "
"retrieved at the same time using the :meth:`~dict.items` method. ::"
msgstr ""
"辞書に対してループを行う際、 :meth:`~dict.items` メソッドを使うと、キーとそれ"
"に対応する値を同時に取り出せます。 ::"

#: ../../tutorial/datastructures.rst:640
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 ""
">>> 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"

#: ../../tutorial/datastructures.rst:647
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 ""
"シーケンスにわたるループを行う際、 :func:`enumerate` 関数を使うと、要素のイン"
"デックスと要素を同時に取り出すことができます。 ::"

#: ../../tutorial/datastructures.rst:650
msgid ""
">>> for i, v in enumerate(['tic', 'tac', 'toe']):\n"
"...     print(i, v)\n"
"...\n"
"0 tic\n"
"1 tac\n"
"2 toe"
msgstr ""
">>> for i, v in enumerate(['tic', 'tac', 'toe']):\n"
"...     print(i, v)\n"
"...\n"
"0 tic\n"
"1 tac\n"
"2 toe"

#: ../../tutorial/datastructures.rst:657
msgid ""
"To loop over two or more sequences at the same time, the entries can be "
"paired with the :func:`zip` function. ::"
msgstr ""
"二つまたはそれ以上のシーケンス型を同時にループするために、関数 :func:`zip` を"
"使って各要素をひと組みにすることができます。 ::"

#: ../../tutorial/datastructures.rst:660
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 ""
">>> 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."

msgid ""
"To loop over a sequence in reverse, first specify the sequence in a forward "
"direction and then call the :func:`reversed` function. ::"
msgstr ""
"シーケンスを逆順にループするには、まずシーケンスを順方向で指定し、それから :"
"func:`reversed` 関数を呼び出します。 ::"

#: ../../tutorial/datastructures.rst:672
msgid ""
">>> for i in reversed(range(1, 10, 2)):\n"
"...     print(i)\n"
"...\n"
"9\n"
"7\n"
"5\n"
"3\n"
"1"
msgstr ""
">>> for i in reversed(range(1, 10, 2)):\n"
"...     print(i)\n"
"...\n"
"9\n"
"7\n"
"5\n"
"3\n"
"1"

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 ""
"シーケンスをソートされた順序でループするには、 :func:`sorted` 関数を使いま"
"す。\n"
"この関数は元のシーケンスを変更せず、ソート済みの新たなリストを返します。 ::"

#: ../../tutorial/datastructures.rst:684
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 ""
">>> 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"

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 ""
"シーケンスに :func:`set` を使うと、重複する要素を取り除けます。\n"
":func:`sorted` と :func:`set` を組み合わせると、シーケンスの要素から重複を除"
"き、\n"
"ソート順にループできます。\n"
"これはよく使われる書き方です。 ::"

#: ../../tutorial/datastructures.rst:699
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 ""
">>> 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"

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 ""
"リストを反復処理しながらそのリストを変更したくなることもありますが、代わりに"
"新しいリストを作る方が簡単で安全なことがよくあります。 ::"

#: ../../tutorial/datastructures.rst:711
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 ""
">>> 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]"

#: ../../tutorial/datastructures.rst:725
msgid "More on Conditions"
msgstr "条件についてもう少し"

#: ../../tutorial/datastructures.rst:727
msgid ""
"The conditions used in ``while`` and ``if`` statements can contain any "
"operators, not just comparisons."
msgstr ""
"``while`` や ``if`` 文で使った条件 (condition) には、値の比較だけでなく、他の"
"演算子も使うことができます。"

#: ../../tutorial/datastructures.rst:731
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 ""
"比較演算子 ``in`` および ``not in`` は、ある値があるコンテナーの中に存在する"
"か (または存在しないか) どうかを確認するメンバーシップテストです。演算子 "
"``is`` および ``is not`` は、二つのオブジェクトが実際に同じオブジェクトである"
"かどうかを調べます。全ての比較演算子は同じ優先順位を持っており、ともに数値演"
"算子よりも低い優先順位となります。"

#: ../../tutorial/datastructures.rst:737
msgid ""
"Comparisons can be chained.  For example, ``a < b == c`` tests whether ``a`` "
"is less than ``b`` and moreover ``b`` equals ``c``."
msgstr ""
"比較は連結させることができます。例えば、 ``a < b == c`` は、 ``a`` が ``b`` "
"より小さく、かつ ``b`` と ``c`` が等しいかどうかをテストします。"

#: ../../tutorial/datastructures.rst:740
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 ""
"ブール演算子 ``and`` や ``or`` で比較演算を組み合わせることができます。そし"
"て、比較演算 (あるいは何らかのブール式) の結果の否定は ``not`` でとれます。こ"
"れらの演算子は全て、比較演算子よりも低い優先順位になっています。 ``A and not "
"B or C`` と ``(A and (not B)) or C`` が等価になるように、ブール演算子の中"
"で、 ``not`` の優先順位が最も高く、 ``or`` が最も低くなっています。もちろん、"
"丸括弧を使えば望みの組み合わせを表現できます。"

#: ../../tutorial/datastructures.rst:747
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 ""
"ブール演算子 ``and`` と ``or`` は、いわゆる *短絡 (short-circuit)* 演算子で"
"す。これらの演算子の引数は左から右へと順に評価され、結果が確定した時点で評価"
"を止めます。例えば、 ``A`` と ``C`` は真で ``B`` が偽のとき、 ``A and B and "
"C`` は式 ``C`` を評価しません。一般に、短絡演算子の戻り値をブール値ではなくて"
"一般的な値として用いると、値は最後に評価された引数になります。"

#: ../../tutorial/datastructures.rst:754
msgid ""
"It is possible to assign the result of a comparison or other Boolean "
"expression to a variable.  For example, ::"
msgstr "比較や他のブール式の結果を変数に代入することもできます。例えば、 ::"

#: ../../tutorial/datastructures.rst:757
msgid ""
">>> string1, string2, string3 = '', 'Trondheim', 'Hammer Dance'\n"
">>> non_null = string1 or string2 or string3\n"
">>> non_null\n"
"'Trondheim'"
msgstr ""
">>> string1, string2, string3 = '', 'Trondheim', 'Hammer Dance'\n"
">>> non_null = string1 or string2 or string3\n"
">>> non_null\n"
"'Trondheim'"

#: ../../tutorial/datastructures.rst:762
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 ""
"Pythonでは、Cとは異なり、式の中での代入は :ref:`セイウチ演算子 <why-can-t-i-"
"use-an-assignment-in-an-expression>` ``:=`` を使用して明示的に行う必要がある"
"ことに注意してください。これにより、 ``==`` が意図されていたところに ``=`` を"
"入力してしまうという、Cプログラムで発生する一般的なクラスの問題を回避できま"
"す。"

#: ../../tutorial/datastructures.rst:772
msgid "Comparing Sequences and Other Types"
msgstr "シーケンスとその他の型の比較"

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 ""
"概して、シーケンスオブジェクトは、同じシーケンス型の他のオブジェクトと比較で"
"きます。\n"
"比較には *辞書的な (lexicographical)* 順序が用いられます。\n"
"まず、二つのシーケンスの先頭要素同士を比較し、その値が等しくなければその時点"
"で比較結果が決まります。\n"
"等しければ次の二つの要素を比較し、以降シーケンスの要素が尽きるまで続けま"
"す。\n"
"比較しようとする二つの要素がいずれも同じシーケンス型であれば、そのシーケンス"
"間での辞書比較を再帰的に行います。\n"
"二つのシーケンスの全ての要素の比較結果が等しくなれば、シーケンスは等しいとみ"
"なされます。\n"
"片方のシーケンスがもう一方の先頭部分にあたる部分シーケンスならば、短い方の"
"シーケンスが小さいシーケンスとみなされます。\n"
"文字列に対する辞書的な順序づけには、個々の文字ごとに Unicode コードポイントの"
"数値による順序を用います。\n"
"以下に、同じ型のシーケンス間での比較を行った例を示します。 ::"

#: ../../tutorial/datastructures.rst:785
msgid ""
"(1, 2, 3)              < (1, 2, 4)\n"
"[1, 2, 3]              < [1, 2, 4]\n"
"'ABC' < 'C' < 'Pascal' < 'Python'\n"
"(1, 2, 3, 4)           < (1, 2, 4)\n"
"(1, 2)                 < (1, 2, -1)\n"
"(1, 2, 3)             == (1.0, 2.0, 3.0)\n"
"(1, 2, ('aa', 'ab'))   < (1, 2, ('abc', 'a'), 4)"
msgstr ""
"(1, 2, 3)              < (1, 2, 4)\n"
"[1, 2, 3]              < [1, 2, 4]\n"
"'ABC' < 'C' < 'Pascal' < 'Python'\n"
"(1, 2, 3, 4)           < (1, 2, 4)\n"
"(1, 2)                 < (1, 2, -1)\n"
"(1, 2, 3)             == (1.0, 2.0, 3.0)\n"
"(1, 2, ('aa', 'ab'))   < (1, 2, ('abc', 'a'), 4)"

msgid ""
"Note that comparing objects of different types with ``<`` or ``>`` is legal "
"provided that the objects have appropriate comparison methods.  For example, "
"mixed numeric types are compared according to their numeric value, so 0 "
"equals 0.0, etc.  Otherwise, rather than providing an arbitrary ordering, "
"the interpreter will raise a :exc:`TypeError` exception."
msgstr ""
"異なる型のオブジェクト同士も、適切な比較メソッドがあれば ``<`` や ``>`` で比"
"較できます。\n"
"例えば、異なる数値型は数値としての値に従って比較されるので、0 と 0.0 は等しい"
"とみなされます。\n"
"適切な比較メソッドがない場合、インタープリタは恣意的な順序を付ける代わりに :"
"exc:`TypeError` 例外を送出します。"

#: ../../tutorial/datastructures.rst:801
msgid "Footnotes"
msgstr "脚注"

msgid ""
"Other languages may return the mutated object, which allows method chaining, "
"such as ``d->insert(\"a\")->remove(\"b\")->sort();``."
msgstr ""
"他の言語では変更後のオブジェクトを返して、``d->insert(\"a\")->remove(\"b\")-"
">sort();`` のようなメソッドチェインを許している場合もあります。"