IDLE --- Python のエディタとシェル
**********************************

**ソースコード:** Lib/idlelib/

======================================================================

IDLE は Python の統合開発環境で、学習用環境です。

IDLE は次のような特徴があります:

* クロスプラットホーム: Windows, Unix, macOS で動作します

* コード入力、出力、エラーメッセージの色付け機能を持った Python shell
  (対話的インタプリタ) ウィンドウ

* 多段 Undo、 Python 対応の色づけ、自動的な字下げ、呼び出し情報の表示
  、自動補完、他たくさんの機能をもつマルチウィンドウ・テキストエディタ

* 任意のウィンドウ内での検索、エディタウィンドウ内での置換、複数ファイ
  ルを跨いだ検索 (grep)

* 永続的なブレイクポイント、ステップ実行、グローバルとローカル名前空間
  の視覚化機能を持ったデバッガ

* 設定、ブラウザ群、ほかダイアログ群

The IDLE application is implemented in the "idlelib" package.

This is an *optional module*. If it is missing from your copy of
CPython, look for documentation from your distributor (that is,
whoever provided Python to you). If you are the distributor, see オプ
ションのモジュールの要件.


メニュー
========

IDLE には2種類のメインウィンドウ、Shell ウィンドウと Editor ウィンドウ
があります。 Editor ウィンドウは同時に複数開けます。 Windows と Linux
では、それぞれ個別のトップメニューがあります。 後で解説するそれぞれの
メニューは、ウィンドウがどちらのウィンドウタイプなのかを示しています。

ファイル内の編集 (Edit) => 検索 (Find) で使われるような出力ウィンドウ
(Output ウィンドウ) は editor ウィンドウのサブタイプで、 Editor ウィン
ドウと同じトップメニューを持ちますが、デフォルトタイトルとコンテキスト
メニューが違います。

On macOS, there is one application menu.  It dynamically changes
according to the window currently selected.  It has an IDLE menu, and
some entries described below are moved around to conform to Apple
guidelines.


File メニュー (Shell ウィンドウ、Editor ウィンドウ)
---------------------------------------------------

New File [新規ファイル]
   新しいファイル編集ウィンドウを作成します。

Open... [開く...]
   Open ダイアログを使って既存のファイルをオープンします。

Open Module... [モジュールを開く...]
   既存のモジュールをオープンします (sys.path を検索します)。

Recent Files [最近使ったファイル]
   最近使ったファイルのリストを開きます。ファイルを一つクリックすると
   それを開きます。

Module Browser
   現在 Editor が開いているファイル内にあるクラス、関数、メソッドを木
   構造で可視化します。 Shell からの場合は、先にモジュール選択のダイア
   ログが開きます。

Path Browser [パスブラウザ]
   sys.path ディレクトリ、モジュール、クラスおよびメソッドを木構造で可
   視化します。

Save [保存]
   現在のウィンドウを対応するファイルがあればそこに保存します。開いて
   から、または最後に保存したのちに編集があった場合のウィンドウには、
   ウィンドウタイトルの前後に * が付けられます。対応するファイルがなけ
   れば代わりに Save As が実行されます。

Save As... [名前を付けて保存...]
   Save the current window with a Save As dialog.  The file saved
   becomes the new associated file for the window. (If your file
   manager is set to hide extensions, the current extension will be
   omitted in the file name box. If the new filename has no '.', '.py'
   and '.txt' will be added for Python and text files, except that on
   macOS Aqua,'.py' is added for all files.)

Save Copy As... [コピーとして保存...]
   Save the current window to different file without changing the
   associated file.  (See Save As note above about filename
   extensions.)

Print Window [ウィンドウを印刷]
   現在のウィンドウをデフォルトプリンタで印刷します。

Close Window
   Close the current window (if an unsaved editor, ask to save; if an
   unsaved Shell, ask to quit execution).  Calling "exit()" or
   "close()" in the Shell window also closes Shell.  If this is the
   only window, also exit IDLE.

Exit IDLE
   Close all windows and quit IDLE (ask to save unsaved edit windows).


Edit メニュー (Shell ウィンドウ、Editor ウィンドウ)
---------------------------------------------------

Undo [元に戻す]
   現在のウィンドウに対する最後の変更を Undo (取り消し) します。最大で
   1000 個の変更が Undo できます。

Redo [やり直し]
   現在のウィンドウに対する最後にundoされた変更をRedo(再スタート)しま
   す。

Select All [全て選択]
   カレントウィンドウの内容全体を選択します。

Cut [切り取り]
   システムのクリップボードへ選択された部分をコピーします。それから選
   択された部分を削除します。

Copy [コピー]
   選択された部分をシステムのクリップボードへコピーします。

Paste [貼り付け]
   システムのクリップボードの内容をカレントウィンドウへ挿入します。

クリップボードの機能はコンテキストメニューからも使えます。

Find... [検索...]
   たくさんのオプションをもつ検索ダイアログボックスを開きます。

Find Again [再検索]
   直前の検索があれば、それを繰り返します。

Find Selection [現在の選択を検索]
   現在選択された文字列があれば、それを検索します。

Find in Files... [ファイルから検索...]
   ファイル検索ダイアログを開きます。結果を新しい出力ウィンドウに出力
   します。

Replace... [置換...]
   検索と置換ダイアログを開きます。

Go to Line [指定行へジャンプ]
   Move the cursor to the beginning of the line requested and make
   that line visible.  A request past the end of the file goes to the
   end. Clear any selection and update the line and column status.

Show Completions [補完候補の一覧]
   Open a scrollable list allowing selection of existing names. See
   Completions in the Editing and Navigation section below.

Expand Word [語の展開]
   先頭だけタイプしたものを、同一ウィンドウ内の完全な語と合致するもの
   に展開します。異なる展開を得るためには繰り返します。

Show Call Tip
   After an unclosed parenthesis for a function, open a small window
   with function parameter hints.  See Calltips in the Editing and
   Navigation section below.

Show Surrounding Parens
   囲んでいる括弧をハイライトします。


Format メニュー (Shell ウィンドウ、Editor ウィンドウ)
-----------------------------------------------------

Format Paragraph [パラグラフのフォーマット]
   Rewrap the text block containing the text insert cursor. Avoid code
   lines.  See Format block in the Editing and Navigation section
   below.

Indent Region [領域をインデント]
   選択された行を右へインデント幅分シフトします (デフォルトは空白 4 個
   )。

Dedent Region [領域をインデント解除]
   選択された行を左へインデント幅分シフトします (デフォルトは空白 4 個
   )。

Comment Out Region [領域をコメントアウト]
   選択された行の先頭に ## を挿入します。

Uncomment Region [領域のコメントを解除]
   選択された行から先頭の # あるいは ## を取り除きます。

Tabify Region [領域のタブ化]
   *先頭* の一続きの空白をタブに置き換えます (注意: Python コードのイ
   ンデントには 4 つの空白を使うことをお勧めします)。

Untabify Region [領域の非タブ化]
   *すべての* タブを適切な数の空白に置き換えます。

Toggle Tabs [タブの切り替え]
   字下げのために空白を使うかタブを使うかを切り替えるダイアログを開き
   ます。

New Indent Width [新しいインデント幅]
   インデント幅を変更するダイアログを開きます。Python コミュニティによ
   って受け容れられているデフォルトは空白 4 個です。

Strip Trailing Whitespace
   Remove trailing space and other whitespace characters after the
   last non-whitespace character of a line by applying "str.rstrip()"
   to each line, including lines within multiline strings.  Except for
   Shell windows, remove extra newlines at the end of the file.


Run メニュー (Editor ウィンドウのみ)
------------------------------------

Run Module [モジュールの実行]
   Check Module を実行します。エラーがなければ Shell の環境をクリーン
   にして再スタートした上で、モジュールを実行します。出力は Shell ウィ
   ンドウに表示されます。"print" や "write" しない限り、この出力はされ
   ません。モジュール実行が完了すると Shell はフォーカスされた状態のま
   まで、プロンプトを表示します。これにより対話的に実行結果を調べるこ
   とができます。この機能は、コマンドラインからファイルを "python -i
   file" で実行することに相当します。

Run... Customized
   Same as Run Module, but run the module with customized settings.
   *Command Line Arguments* extend "sys.argv" as if passed on a
   command line. The module can be run in the Shell without
   restarting.

Check Module [モジュールのチェック]
   Editor ウィンドウでいま開いているモジュールを構文チェックします。モ
   ジュールが未保存の場合、 Options -> Configure IDLE -> General の
   "Autosave Preferences" の設定にもとづき、確認を求められるか自動的に
   保存します。構文エラーが見つかると Editor ウィンドウでそのおよその
   位置に移動します。

Python Shell [Python シェル]
   Python Shell ウィンドウを開くか、起こします。


Shell メニュー (Shell ウィンドウのみ)
-------------------------------------

View Last Restart [最後のリスタートを表示する]
   最後に Shell のリスタートを行った場所まで Shell ウインドウをスクロ
   ールします。

Restart Shell [Shell のリスタート]
   Restart the shell to clean the environment and reset display and
   exception handling.

Previous History
   Cycle through earlier commands in history which match the current
   entry.

Next History
   Cycle through later commands in history which match the current
   entry.

Interrupt Execution [実行の中断]
   プログラムの実行を停止します。


Debug メニュー (Shell ウィンドウのみ)
-------------------------------------

Go to File/Line [ファイル/行へ移動]
   カーソルのある現在行の上にファイル名と行番号が見つかれば、(開かれて
   いなければ) そのファイルを開いてその行に飛びます。例外のトレースバ
   ックが参照しているソース行を見るのにこれを使いましょう。そのような
   ファイル名・行番号表示をしている行を見つけるのには Find を使えます
   。この機能は Shell ウィンドウと Output ウィンドウのコンテキストメニ
   ューからも使えます。

Debugger [デバッガ] (トグル切り替え)
   アクティブにすると、Shell または Editor に入力したコードをデバッガ
   のもとで実行します。Editor ではコンテキストメニューからブレイクポイ
   ントをセット出来ます。この機能はまだ不完全で、少々実験的です。

Stack Viewer [スタックビューア]
   最後の例外のスタックトレースと locals 辞書、 globals 辞書をツリーウ
   ィジットで表示します。

Auto-open Stack Viewer [スタックビューアの自動オープン]
   未捕捉の例外時にスタックビューアを自動的に開くかどうかを切り替えま
   す。


Options メニュー (Shell ウィンドウ、Editor ウィンドウ)
------------------------------------------------------

Configure IDLE [IDLE の設定]
   Open a configuration dialog and change preferences for the
   following: fonts, indentation, keybindings, text color themes,
   startup windows and size, additional help sources, and extensions.
   On macOS, open the configuration dialog by selecting Preferences in
   the application menu. For more details, see Setting preferences
   under Help and preferences.

Most configuration options apply to all windows or all future windows.
The option items below only apply to the active window.

Show/Hide Code Context (Editor Window only)
   Editor ウィンドウの上部にペインが開き、そこにウィンドウの一番上のコ
   ードのブロックコンテキスト (訳注: コードが含まれているブロックのイ
   ンデント構造) が表示されます。 下の編集とナビゲーションの節にある
   コードコンテキスト の項を参照してください。

Show/Hide Line Numbers (Editor Window only)
   Open a column to the left of the edit window which shows the number
   of each line of text.  The default is off, which may be changed in
   the preferences (see Setting preferences).

Zoom/Restore Height
   Toggles the window between normal size and maximum height. The
   initial size defaults to 40 lines by 80 chars unless changed on the
   General tab of the Configure IDLE dialog.  The maximum height for a
   screen is determined by momentarily maximizing a window the first
   time one is zoomed on the screen. Changing screen settings may
   invalidate the saved height.  This toggle has no effect when a
   window is maximized.


Window メニュー (Shell ウィンドウ、Editor ウィンドウ)
-----------------------------------------------------

Lists the names of all open windows; select one to bring it to the
foreground (deiconifying it if necessary).


Help メニュー (Shell ウィンドウ、Editor ウィンドウ)
---------------------------------------------------

About IDLE [IDLE について]
   バージョン、コピーライト、ライセンス、クレジット、その他を表示しま
   す。

IDLE Help [IDLE ヘルプ]
   メニューオプション、基本的な編集やナビゲーションその他チップスを詳
   しく書いた IDLE のドキュメントを表示します。

Python Docs [Python ドキュメント]
   Python ドキュメントがローカルにインストールされていればそれを開きま
   す。もしくはウェブブラウザで最新の Python ドキュメント
   (https://docs.python.org) を開きます。(訳注: いずれも何もしていなけ
   れば英語。下記参照。)

Turtle Demo [Turtle デモ]
   Python コード例とタートルによる描画を使って turtledemo モジュールを
   実行します。

General タブの下の方にある Configure IDLE ダイアログで、追加のヘルプソ
ースを Help メニューに加えられます。 下の編集とナビゲーションの節にあ
る ヘルプソース の項を参照してください。


Context menus
-------------

ウィンドウ内で右クリック (macOS では Control-クリック) でコンテキスト
メニューが開きます。コンテキストメニューには Edit メニューにもある標準
的なクリップボード機能が含まれています。

Cut [切り取り]
   システムのクリップボードへ選択された部分をコピーします。それから選
   択された部分を削除します。

Copy [コピー]
   選択された部分をシステムのクリップボードへコピーします。

Paste [貼り付け]
   システムのクリップボードの内容をカレントウィンドウへ挿入します。

Editor ウィンドウではさらにブレイクポイント機能が使えます。ブレイクポ
イントがセットされた行には、特別に印がつきます。ブレイクポイントはデバ
ッガのもとでの実行にだけ影響します。ファイルに付けたブレイクポイントは
ユーザの ".idlerc" ディレクトリに保存されます。

Set Breakpoint [ブレークポイントのセット]
   現在行にブレークポイントをセットします。

Clear Breakpoint [ブレークポイントのクリア]
   その行のブレークポイントをクリアします。

Shell ウィンドウや Output ウィンドウには次のメニューもあります。

Go to file/line [ファイル/行へ移動]
   Debug メニューと同じものです。

The Shell window also has an output squeezing facility explained in
the *Python Shell window* subsection below.

Squeeze
   If the cursor is over an output line, squeeze all the output
   between the code above and the prompt below down to a 'Squeezed
   text' label.


Editing and Navigation
======================


Editor windows
--------------

IDLE may open editor windows when it starts, depending on settings and
how you start IDLE.  Thereafter, use the File menu.  There can be only
one open editor window for a given file.

The title bar contains the name of the file, the full path, and the
version of Python and IDLE running the window.  The status bar
contains the line number ('Ln') and column number ('Col').  Line
numbers start with 1; column numbers with 0.

IDLE assumes that files with a known .py* extension contain Python
code and that other files do not.  Run Python code with the Run menu.


Key bindings
------------

The IDLE insertion cursor is a thin vertical bar between character
positions.  When characters are entered, the insertion cursor and
everything to its right moves right one character and the new
character is entered in the new space.

Several non-character keys move the cursor and possibly delete
characters.  Deletion does not puts text on the clipboard, but IDLE
has an undo list.  Wherever this doc discusses keys, 'C' refers to the
"Control" key on Windows and Unix and the "Command" key on macOS.
(And all such discussions assume that the keys have not been re-bound
to something else.)

* Arrow keys move the cursor one character or line.

* "C"-"LeftArrow" and "C"-"RightArrow" moves left or right one word.

* "Home" and "End" go to the beginning or end of the line.

* "Page Up" and "Page Down" go up or down one screen.

* "C"-"Home" and "C"-"End" go to beginning or end of the file.

* "Backspace" and "Del" (or "C"-"d") delete the previous or next
  character.

* "C"-"Backspace" and "C"-"Del" delete one word left or right.

* "C"-"k" deletes ('kills') everything to the right.

標準的なキーバインディング ("C"-"c" がコピーで "C"-"v" がペースト、な
ど) は機能するかもしれません。キーバインディングは Configure IDLE ダイ
アログで選択します。


自動的な字下げ
--------------

ブロックの始まりの文の後、次の行は 4 つの空白 (Python Shell ウィンドウ
では、一つのタブ) で字下げされます。あるキーワード (break、return など
) の後では、次の行は字下げが解除 (dedent) されます。先頭の字下げでは、
"Backspace" は 4 つの空白があれば削除します。 "Tab" はインデント幅に対
応する数の空白 (Python Shell ウィンドウでは一つのタブ) を挿入します。
現在、タブは Tcl/Tk の制約のため 4 つの空白に固定されています。

Format メニュー の indent/dedent region コマンドも参照してください。


検索と置換
----------

Any selection becomes a search target.  However, only selections
within a line work because searches are only performed within lines
with the terminal newline removed.  If "[x] Regular expression" is
checked, the target is interpreted according to the Python re module.


補完 (Completions)
------------------

Completions are supplied, when requested and available, for module
names, attributes of classes or functions, or filenames.  Each request
method displays a completion box with existing names.  (See tab
completions below for an exception.) For any box, change the name
being completed and the item highlighted in the box by typing and
deleting characters; by hitting "Up", "Down", "PageUp", "PageDown",
"Home", and "End" keys; and by a single click within the box.  Close
the box with "Escape", "Enter", and double "Tab" keys or clicks
outside the box. A double click within the box selects and closes.

One way to open a box is to type a key character and wait for a
predefined interval.  This defaults to 2 seconds; customize it in the
settings dialog.  (To prevent auto popups, set the delay to a large
number of milliseconds, such as 100000000.) For imported module names
or class or function attributes, type '.'. For filenames in the root
directory, type "os.sep" or "os.altsep" immediately after an opening
quote.  (On Windows, one can specify a drive first.)  Move into
subdirectories by typing a directory name and a separator.

Instead of waiting, or after a box is closed, open a completion box
immediately with Show Completions on the Edit menu.  The default hot
key is "C"-"space".  If one types a prefix for the desired name before
opening the box, the first match or near miss is made visible. The
result is the same as if one enters a prefix after the box is
displayed.  Show Completions after a quote completes filenames in the
current directory instead of a root directory.

Hitting "Tab" after a prefix usually has the same effect as Show
Completions.  (With no prefix, it indents.)  However, if there is only
one match to the prefix, that match is immediately added to the editor
text without opening a box.

Invoking 'Show Completions', or hitting "Tab" after a prefix, outside
of a string and without a preceding '.' opens a box with keywords,
builtin names, and available module-level names.

When editing code in an editor (as oppose to Shell), increase the
available module-level names by running your code and not restarting
the Shell thereafter.  This is especially useful after adding imports
at the top of a file.  This also increases possible attribute
completions.

Completion boxes initially exclude names beginning with '_' or, for
modules, not included in '__all__'.  The hidden names can be accessed
by typing '_' after '.', either before or after the box is opened.


呼び出しヒント (Calltips)
-------------------------

A calltip is shown automatically when one types "(" after the name of
an *accessible* function.  A function name expression may include dots
and subscripts.  A calltip remains until it is clicked, the cursor is
moved out of the argument area, or ")" is typed.  Whenever the cursor
is in the argument part of a definition, select Edit and "Show Call
Tip" on the menu or enter its shortcut to display a calltip.

The calltip consists of the function's signature and docstring up to
the latter's first blank line or the fifth non-blank line.  (Some
builtin functions lack an accessible signature.)  A '/' or '*' in the
signature indicates that the preceding or following arguments are
passed by position or name (keyword) only.  Details are subject to
change.

In Shell, the accessible functions depends on what modules have been
imported into the user process, including those imported by Idle
itself, and which definitions have been run, all since the last
restart.

For example, restart the Shell and enter "itertools.count(".  A
calltip appears because Idle imports itertools into the user process
for its own use.  (This could change.)  Enter "turtle.write(" and
nothing appears. Idle does not itself import turtle.  The menu entry
and shortcut also do nothing.  Enter "import turtle".  Thereafter,
"turtle.write(" will display a calltip.

In an editor, import statements have no effect until one runs the
file. One might want to run a file after writing import statements,
after adding function definitions, or after opening an existing file.


Format block
------------

Reformat Paragraph rewraps a block ('paragraph') of contiguous equally
indented non-blank comments, a similar block of text within a
multiline string, or a selected subset of either. If needed, add a
blank line to separate string from code. Partial lines in a selection
expand to complete lines. The resulting lines have the same indent as
before but have maximum total length of N columns (characters). Change
the default N of 72 on the Window tab of IDLE Settings.


Code Context
------------

Within an editor window containing Python code, code context can be
toggled in order to show or hide a pane at the top of the window.
When shown, this pane freezes the opening lines for block code, such
as those beginning with "class", "def", or "if" keywords, that would
have otherwise scrolled out of view.  The size of the pane will be
expanded and contracted as needed to show the all current levels of
context, up to the maximum number of lines defined in the Configure
IDLE dialog (which defaults to 15).  If there are no current context
lines and the feature is toggled on, a single blank line will display.
Clicking on a line in the context pane will move that line to the top
of the editor.

The text and background colors for the context pane can be configured
under the Highlights tab in the Configure IDLE dialog.


Shell window
------------

In IDLE's Shell, enter, edit, and recall complete statements. (Most
consoles and terminals only work with a single physical line at a
time).

Submit a single-line statement for execution by hitting "Return" with
the cursor anywhere on the line.  If a line is extended with Backslash
("\"), the cursor must be on the last physical line. Submit a multi-
line compound statement by entering a blank line after the statement.

When one pastes code into Shell, it is not compiled and possibly
executed until one hits "Return", as specified above. One may edit
pasted code first. If one pastes more than one statement into Shell,
the result will be a "SyntaxError" when multiple statements are
compiled as if they were one.

Lines containing "RESTART" mean that the user execution process has
been re-started.  This occurs when the user execution process has
crashed, when one requests a restart on the Shell menu, or when one
runs code in an editor window.

The editing features described in previous subsections work when
entering code interactively.  IDLE's Shell window also responds to the
following:

* "C"-"c" attempts to interrupt statement execution (but may fail).

* "C"-"d" closes Shell if typed at a ">>>" prompt.

* "Alt"-"p" and "Alt"-"n" ("C"-"p" and "C"-"n" on macOS) retrieve to
  the current prompt the previous or next previously entered statement
  that matches anything already typed.

* "Return" while the cursor is on any previous statement appends the
  latter to anything already typed at the prompt.


テキストの色
------------

IDLE の表示はデフォルトで白背景に黒字ですが、以下のような特別な意味を
持ったテキストには色が付きす。Shell では shell 出力、 shell エラー、ユ
ーザエラー。Python コードでは Shell プロンプト内や Editor でのキーワー
ド、組み込みクラスや組み込み関数の名前、 "class" や "def" に続く名前、
文字列、そしてコメント。どんなテキストウィンドウでも、カーソル (あれば
)、検索で合致したテキスト (あれば)、そして選択されているテキストには色
が付きます。

IDLE also highlights the soft keywords "match", "case", and "_" in
pattern-matching statements. However, this highlighting is not perfect
and will be incorrect in some rare cases, including some "_"-s in
"case" patterns.

このテキストの色付けはバックグラウンドで行われるため、たまに色が付いて
ない状態が見えてしまいます。カラースキームは、 Configure IDLE [IDLE の
設定] ダイアログの Highlighting タブで変更できます。ただし、エディタ内
のデバッガブレークポイント行のマーキングと、ポップアップとダイアログな
いのテキストの色は、ユーザーにより変更することはできません。


Startup and Code Execution
==========================

"-s" オプションとともに起動すると、IDLE は環境変数 "IDLESTARTUP" か
"PYTHONSTARTUP" で参照されているファイルを実行します。 IDLE はまず
"IDLESTARTUP" をチェックし、あれば参照しているファイルを実行します。
"IDLESTARTUP" が無ければ、IDLE は "PYTHONSTARTUP" をチェックします。こ
れらの環境変数で参照されているファイルは、IDLE シェルでよく使う関数を
置いたり、一般的なモジュールの import 文を実行するのに便利です。

加えて、"Tk" もスタートアップファイルがあればそれをロードします。その
Tk のファイルは無条件にロードされることに注意してください。このファイ
ルは ".Idle.py" で、ユーザーのホームディレクトリから探されます。このフ
ァイルの中の文は Tk の名前空間で実行されるので、IDLE の Python シェル
で使う関数を import するのには便利ではありません。


コマンドラインでの使用
----------------------

IDLE can be invoked from the command line with various options. The
general syntax is:

   python -m idlelib [options] [file ...]

The following options are available:

-c <command>

   Run the specified Python command in the shell window. For example,
   pass "-c "print('Hello, World!')"". On Windows, the outer quotes
   must be double quotes as shown.

-d

   Enable the debugger and open the shell window.

-e

   Open an editor window.

-h

   Print a help message with legal combinations of options and exit.

-i

   Open a shell window.

-r <file>

   Run the specified file in the shell window.

-s

   Run the startup file (as defined by the environment variables
   "IDLESTARTUP" or "PYTHONSTARTUP") before opening the shell window.

-t <title>

   Set the title of the shell window.

-

   Read and execute standard input in the shell window. This option
   must be the last one before any arguments.

If arguments are provided:

* If "-", "-c", or "-r" is used, all arguments are placed in
  "sys.argv[1:]", and "sys.argv[0]" is set to "''", "'-c'", or "'-r'"
  respectively. No editor window is opened, even if that is the
  default set in the *Options* dialog.

* Otherwise, arguments are treated as files to be opened for editing,
  and "sys.argv" reflects the arguments passed to IDLE itself.


Startup failure
---------------

IDLE uses a socket to communicate between the IDLE GUI process and the
user code execution process.  A connection must be established
whenever the Shell starts or restarts.  (The latter is indicated by a
divider line that says 'RESTART'). If the user process fails to
connect to the GUI process, it usually displays a "Tk" error box with
a 'cannot connect' message that directs the user here.  It then exits.

One specific connection failure on Unix systems results from
misconfigured masquerading rules somewhere in a system's network
setup. When IDLE is started from a terminal, one will see a message
starting with "** Invalid host:". The valid value is "127.0.0.1
(idlelib.rpc.LOCALHOST)". One can diagnose with "tcpconnect -irv
127.0.0.1 6543" in one terminal window and "tcplisten <same args>" in
another.

A common cause of failure is a user-written file with the same name as
a standard library module, such as *random.py* and *tkinter.py*. When
such a file is located in the same directory as a file that is about
to be run, IDLE cannot import the stdlib file.  The current fix is to
rename the user file.

Though less common than in the past, an antivirus or firewall program
may stop the connection.  If the program cannot be taught to allow the
connection, then it must be turned off for IDLE to work.  It is safe
to allow this internal connection because no data is visible on
external ports.  A similar problem is a network mis-configuration that
blocks connections.

Python installation issues occasionally stop IDLE: multiple versions
can clash, or a single installation might need admin access.  If one
undo the clash, or cannot or does not want to run as admin, it might
be easiest to completely remove Python and start over.

A zombie pythonw.exe process could be a problem.  On Windows, use Task
Manager to check for one and stop it if there is.  Sometimes a restart
initiated by a program crash or Keyboard Interrupt (control-C) may
fail to connect.  Dismissing the error box or using Restart Shell on
the Shell menu may fix a temporary problem.

When IDLE first starts, it attempts to read user configuration files
in "~/.idlerc/" (~ is one's home directory).  If there is a problem,
an error message should be displayed.  Leaving aside random disk
glitches, this can be prevented by never editing the files by hand.
Instead, use the configuration dialog, under Options.  Once there is
an error in a user configuration file, the best solution may be to
delete it and start over with the settings dialog.

If IDLE quits with no message, and it was not started from a console,
try starting it from a console or terminal ("python -m idlelib") and
see if this results in an error message.

On Unix-based systems with tcl/tk older than "8.6.11" (see "About
IDLE") certain characters of certain fonts can cause a tk failure with
a message to the terminal.  This can happen either if one starts IDLE
to edit a file with such a character or later when entering such a
character.  If one cannot upgrade tcl/tk, then re-configure IDLE to
use a font that works better.


Running user code
-----------------

With rare exceptions, the result of executing Python code with IDLE is
intended to be the same as executing the same code by the default
method, directly with Python in a text-mode system console or terminal
window. However, the different interface and operation occasionally
affect visible results.  For instance, "sys.modules" starts with more
entries, and "threading.active_count()" returns 2 instead of 1.

By default, IDLE runs user code in a separate OS process rather than
in the user interface process that runs the shell and editor.  In the
execution process, it replaces "sys.stdin", "sys.stdout", and
"sys.stderr" with objects that get input from and send output to the
Shell window. The original values stored in "sys.__stdin__",
"sys.__stdout__", and "sys.__stderr__" are not touched, but may be
"None".

Sending print output from one process to a text widget in another is
slower than printing to a system terminal in the same process. This
has the most effect when printing multiple arguments, as the string
for each argument, each separator, the newline are sent separately.
For development, this is usually not a problem, but if one wants to
print faster in IDLE, format and join together everything one wants
displayed together and then print a single string.  Both format
strings and "str.join()" can help combine fields and lines.

IDLE's standard stream replacements are not inherited by subprocesses
created in the execution process, whether directly by user code or by
modules such as multiprocessing.  If such subprocess use "input" from
sys.stdin or "print" or "write" to sys.stdout or sys.stderr, IDLE
should be started in a command line window.  (On Windows, use "python"
or "py" rather than "pythonw" or "pyw".) The secondary subprocess will
then be attached to that window for input and output.

If "sys" is reset by user code, such as with "importlib.reload(sys)",
IDLE's changes are lost and input from the keyboard and output to the
screen will not work correctly.

When Shell has the focus, it controls the keyboard and screen.  This
is normally transparent, but functions that directly access the
keyboard and screen will not work.  These include system-specific
functions that determine whether a key has been pressed and if so,
which.

The IDLE code running in the execution process adds frames to the call
stack that would not be there otherwise.  IDLE wraps
"sys.getrecursionlimit" and "sys.setrecursionlimit" to reduce the
effect of the additional stack frames.

When user code raises SystemExit either directly or by calling
sys.exit, IDLE returns to a Shell prompt instead of exiting.


User output in Shell
--------------------

When a program outputs text, the result is determined by the
corresponding output device.  When IDLE executes user code,
"sys.stdout" and "sys.stderr" are connected to the display area of
IDLE's Shell.  Some of its features are inherited from the underlying
Tk Text widget.  Others are programmed additions.  Where it matters,
Shell is designed for development rather than production runs.

For instance, Shell never throws away output.  A program that sends
unlimited output to Shell will eventually fill memory, resulting in a
memory error. In contrast, some system text windows only keep the last
n lines of output. A Windows console, for instance, keeps a user-
settable 1 to 9999 lines, with 300 the default.

A Tk Text widget, and hence IDLE's Shell, displays characters
(codepoints) in the BMP (Basic Multilingual Plane) subset of Unicode.
Which characters are displayed with a proper glyph and which with a
replacement box depends on the operating system and installed fonts.
Tab characters cause the following text to begin after the next tab
stop. (They occur every 8 'characters').  Newline characters cause
following text to appear on a new line.  Other control characters are
ignored or displayed as a space, box, or something else, depending on
the operating system and font.  (Moving the text cursor through such
output with arrow keys may exhibit some surprising spacing behavior.)

   >>> s = 'a\tb\a<\x02><\r>\bc\nd'  # Enter 22 chars.
   >>> len(s)
   14
   >>> s  # Display repr(s)
   'a\tb\x07<\x02><\r>\x08c\nd'
   >>> print(s, end='')  # Display s as is.
   # Result varies by OS and font.  Try it.

The "repr" function is used for interactive echo of expression values.
It returns an altered version of the input string in which control
codes, some BMP codepoints, and all non-BMP codepoints are replaced
with escape codes. As demonstrated above, it allows one to identify
the characters in a string, regardless of how they are displayed.

Normal and error output are generally kept separate (on separate
lines) from code input and each other.  They each get different
highlight colors.

For SyntaxError tracebacks, the normal '^' marking where the error was
detected is replaced by coloring the text with an error highlight.
When code run from a file causes other exceptions, one may right click
on a traceback line to jump to the corresponding line in an IDLE
editor. The file will be opened if necessary.

Shell has a special facility for squeezing output lines down to a
'Squeezed text' label.  This is done automatically for output over N
lines (N = 50 by default). N can be changed in the PyShell section of
the General page of the Settings dialog.  Output with fewer lines can
be squeezed by right clicking on the output.  This can be useful lines
long enough to slow down scrolling.

Squeezed output is expanded in place by double-clicking the label. It
can also be sent to the clipboard or a separate view window by right-
clicking the label.


Developing tkinter applications
-------------------------------

IDLE is intentionally different from standard Python in order to
facilitate development of tkinter programs.  Enter "import tkinter as
tk; root = tk.Tk()" in standard Python and nothing appears.  Enter the
same in IDLE and a tk window appears.  In standard Python, one must
also enter "root.update()" to see the window.  IDLE does the
equivalent in the background, about 20 times a second, which is about
every 50 milliseconds. Next enter "b = tk.Button(root, text='button');
b.pack()".  Again, nothing visibly changes in standard Python until
one enters "root.update()".

Most tkinter programs run "root.mainloop()", which usually does not
return until the tk app is destroyed.  If the program is run with
"python -i" or from an IDLE editor, a ">>>" shell prompt does not
appear until "mainloop()" returns, at which time there is nothing left
to interact with.

When running a tkinter program from an IDLE editor, one can comment
out the mainloop call.  One then gets a shell prompt immediately and
can interact with the live application.  One just has to remember to
re-enable the mainloop call when running in standard Python.


サブプロセスを起こさずに起動する
--------------------------------

デフォルトでは、IDLE でのユーザコードの実行は、内部的なループバックイ
ンターフェイスを使用する、ソケット経由の分離されたサブプロセスで行われ
ます。この接続は外部からは見えませんし、インターネットとのデータの送受
信は行われません。ファイアウォールソフトウェアの警告が発生しても、無視
して構いません。

ソケット接続の確立を試みて失敗した場合、IDLE によって通知されます。こ
のような失敗は一過性の場合もありますが、永続的に失敗する場合は、ファイ
アウォールが接続をブロックしているか、特定のシステムの設定が誤っている
ことが原因かもしれません。問題が解決するまでは、 IDLE をコマンドライン
オプション "-n" で起動することもできます。

IDLE を "-n" コマンドラインスイッチを使って開始した場合、IDLE は単一の
プロセス内で動作し、RPC Python 実行サーバを走らせるサブプロセスを作り
ません。これは、プラットフォーム上で Python がサブプロセスや RPC ソケ
ットインターフェイスを作れない場合に有用かもしれません。ただし、このモ
ードではユーザコードが IDLE 自身から隔離されませんし、Run/Run Module
(F5) 選択時に環境が再起動されてまっさらな状態になることもありません。
コードを変更した場合、影響するモジュールを reload() しないといけません
し、変更を反映するには、すべての特定の項目 ("from foo import baz" など
) を再インポートしないといけません。これらの理由から、可能なら常にデフ
ォルトのサブプロセスを起こすモードで IDLE を起動するのが吉です。

バージョン 3.4 で非推奨.


Help and Preferences
====================


Help sources
------------

Help menu entry "IDLE Help" displays a formatted html version of the
IDLE chapter of the Library Reference.  The result, in a read-only
tkinter text window, is close to what one sees in a web browser.
Navigate through the text with a mousewheel, the scrollbar, or up and
down arrow keys held down. Or click the TOC (Table of Contents) button
and select a section header in the opened box.

Help menu entry "Python Docs" opens the extensive sources of help,
including tutorials, available at "docs.python.org/x.y", where 'x.y'
is the currently running Python version.  If your system has an off-
line copy of the docs (this may be an installation option), that will
be opened instead.

Selected URLs can be added or removed from the help menu at any time
using the General tab of the Configure IDLE dialog.


Setting preferences [お好み設定]
--------------------------------

The font preferences, highlighting, keys, and general preferences can
be changed via Configure IDLE on the Option menu. Non-default user
settings are saved in a ".idlerc" directory in the user's home
directory.  Problems caused by bad user configuration files are solved
by editing or deleting one or more of the files in ".idlerc".

On the Font tab, see the text sample for the effect of font face and
size on multiple characters in multiple languages.  Edit the sample to
add other characters of personal interest.  Use the sample to select
monospaced fonts.  If particular characters have problems in Shell or
an editor, add them to the top of the sample and try changing first
size and then font.

On the Highlights and Keys tab, select a built-in or custom color
theme and key set.  To use a newer built-in color theme or key set
with older IDLEs, save it as a new custom theme or key set and it well
be accessible to older IDLEs.


IDLE on macOS
-------------

Under System Preferences: Dock, one can set "Prefer tabs when opening
documents" to "Always".  This setting is not compatible with the
tk/tkinter GUI framework used by IDLE, and it breaks a few IDLE
features.


Extensions [拡張]
-----------------

IDLE contains an extension facility.  Preferences for extensions can
be changed with the Extensions tab of the preferences dialog. See the
beginning of config-extensions.def in the idlelib directory for
further information.  The only current default extension is zzdummy,
an example also used for testing.


idlelib --- implementation of IDLE application
==============================================

**Source code:** Lib/idlelib

======================================================================

The Lib/idlelib package implements the IDLE application.  See the rest
of this page for how to use IDLE.

The files in idlelib are described in idlelib/README.txt.  Access it
either in idlelib or click Help => About IDLE on the IDLE menu.  This
file also maps IDLE menu items to the code that implements the item.
Except for files listed under 'Startup', the idlelib code is 'private'
in sense that feature changes can be backported (see **PEP 434**).
