python-clinic / Lib / idlelib / help.txt

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[See the end of this file for ** TIPS ** on using IDLE !!]

IDLE is the Python IDE built with the tkinter GUI toolkit.

IDLE has the following features:
-coded in 100% pure Python, using the tkinter GUI toolkit
-cross-platform: works on Windows, Unix, and OS X
-multi-window text editor with multiple undo, Python colorizing, smart indent,
call tips, and many other features
-Python shell window (a.k.a interactive interpreter)
-debugger (not complete, but you can set breakpoints, view and step)


IDLE has two window types the Shell window and the Editor window. It is
possible to have multiple editor windows simultaneously. IDLE's
menus dynamically change based on which window is currently selected. Each menu
documented below indicates which window type it is associated with. Click on
the dotted line at the top of a menu to "tear it off": a separate window
containing the menu is created (for Unix and Windows only).

File Menu (Shell and Editor):

        New File         -- Create a new file editing window
        Open...          -- Open an existing file
        Open Module...   -- Open an existing module (searches sys.path)
        Recent Files...  -- Open a list of recent files
        Class Browser    -- Show classes and methods in current file
        Path Browser     -- Show sys.path directories, modules, classes,
                            and methods
        Save             -- Save current window to the associated file (unsaved
                            windows have a * before and after the window title)

        Save As...       -- Save current window to new file, which becomes
                            the associated file
        Save Copy As...  -- Save current window to different file
                            without changing the associated file
        Print Window     -- Print the current window
        Close            -- Close current window (asks to save if unsaved)
        Exit             -- Close all windows, quit (asks to save if unsaved)

Edit Menu (Shell and Editor):

        Undo             -- Undo last change to current window
                            (a maximum of 1000 changes may be undone)
        Redo             -- Redo last undone change to current window
        Cut              -- Copy a selection into system-wide clipboard,
                            then delete the selection
        Copy             -- Copy selection into system-wide clipboard
        Paste            -- Insert system-wide clipboard into window
        Select All       -- Select the entire contents of the edit buffer
        Find...          -- Open a search dialog box with many options
        Find Again       -- Repeat last search
        Find Selection   -- Search for the string in the selection
        Find in Files... -- Open a search dialog box for searching files
        Replace...       -- Open a search-and-replace dialog box
        Go to Line       -- Ask for a line number and show that line
        Expand Word      -- Expand the word you have typed to match another
                            word in the same buffer; repeat to get a
                            different expansion
        Show Calltip     -- After an unclosed parenthesis for a function, open
                            a small window with function parameter hints
        Show Parens      -- Highlight the surrounding parenthesis
        Show Completions -- Open a scroll window allowing selection keywords
                            and attributes. (see '*TIPS*', below)

Format Menu (Editor window only):

        Indent Region       -- Shift selected lines right by the indent width
                               (default 4 spaces)
        Dedent Region       -- Shift selected lines left by the indent width
                               (default 4 spaces)
        Comment Out Region  -- Insert ## in front of selected lines
        Uncomment Region    -- Remove leading # or ## from selected lines
        Tabify Region       -- Turns *leading* stretches of spaces into tabs.
                (Note: We recommend using 4 space blocks to indent Python code.)
        Untabify Region     -- Turn *all* tabs into the corrent number of spaces
        Toggle tabs         -- Open a dialog to switch between indenting with
                               spaces and tabs.
        New Indent Width... -- Open a dialog to change indent width.  The
                               accepted default by the Python community is 4
        Format Paragraph    -- Reformat the current blank-line-separated
                               paragraph. All lines in the paragraph will be
                               formatted to less than 80 columns.
        Strip trailing whitespace -- Removed any space characters after the end
                                     of the last non-space character

Run Menu (Editor window only):

        Python Shell -- Open or wake up the Python shell window
        Check Module -- Check the syntax of the module currently open in the
                        Editor window.  If the module has not been saved IDLE
                        will prompt the user to save the code.
        Run Module   -- Restart the shell to clean the environment, then
                        execute the currently open module. If the module has
                        not been saved IDLE will prompt the user to save the

Shell Menu (Shell window only):

        View Last Restart -- Scroll the shell window to the last Shell restart
        Restart Shell     -- Restart the shell to clean the environment

Debug Menu (Shell window only):

        Go to File/Line   -- Look around the insert point for a filename
                             and line number, open the file, and show the line.
                             Useful to view the source lines referenced in an
                             exception traceback.  Available in the context
                             menu of the Shell window.
        Debugger (toggle) -- This feature is not complete and considered
                             experimental. Run commands in the shell under the
        Stack Viewer      -- Show the stack traceback of the last exception
        Auto-open Stack Viewer (toggle) -- Toggle automatically opening the
                                           stack viewer on unhandled

Options Menu (Shell and Editor):

        Configure IDLE -- Open a configuration dialog.  Fonts, indentation,
                          keybindings, and color themes may be altered.
                          Startup Preferences may be set, and additional Help
                          sources can be specified.

        Code Context (toggle) -- Open a pane at the top of the edit window
                                 which shows the block context of the section
                                 of code which is scrolling off the top or the
                                 window. This is not present in the Shell
                                 window only the Editor window.

Windows Menu (Shell and Editor):

        Zoom Height -- Toggles the window between normal size (40x80 initial
        setting) and maximum height.  The initial size is in the Configure
        IDLE dialog under the general tab.
        The rest of this menu lists the names of all open windows;
        select one to bring it to the foreground (deiconifying it if

Help Menu:

        About IDLE  -- Version, copyright, license, credits
        IDLE Help   -- Display this file which is a help file for IDLE
                       detailing the menu options, basic editing and navigation,
                       and other tips.
        Python Docs -- Access local Python documentation, if
                       installed.  Or will start a web browser and open
              showing the latest Python documentation.
        Additional help sources may be added here with the Configure IDLE
        dialog under the General tab.

Editor context menu (Right-click / Control-click on OS X in Edit window):

        Cut              -- Copy a selection into system-wide clipboard,
                            then delete the selection
        Copy             -- Copy selection into system-wide clipboard
        Paste            -- Insert system-wide clipboard into window
        Set Breakpoint   -- Sets a breakpoint. Breakpoints are only enabled
                            when the debugger is open.
        Clear Breakpoint -- Clears the breakpoint on that line

Shell context menu (Right-click / Control-click on OS X in Shell window):

        Cut              -- Copy a selection into system-wide clipboard,
                            then delete the selection
        Copy             -- Copy selection into system-wide clipboard
        Paste            -- Insert system-wide clipboard into window
        Go to file/line  -- Same as in Debug menu

** TIPS **

Additional Help Sources:

        Windows users can Google on zopeshelf.chm to access Zope help files in
        the Windows help format.  The Additional Help Sources feature of the
        configuration GUI supports .chm, along with any other filetypes
        supported by your browser.  Supply a Menu Item title, and enter the
        location in the Help File Path slot of the New Help Source dialog.  Use
        http:// and/or www. to identify external URLs, or download the file and
        browse for its path on your machine using the Browse button.

        All users can access the extensive sources of help, including
        tutorials, available at  Selected URLs can be added
        or removed from the Help menu at any time using Configure IDLE.

Basic editing and navigation:

        Backspace deletes char to the left; DEL deletes char to the right.
        Control-backspace deletes word left, Control-DEL deletes word right.
        Arrow keys and Page Up/Down move around.
        Control-left/right Arrow moves by words in a strange but useful way.
        Home/End go to begin/end of line.
        Control-Home/End go to begin/end of file.
        Some useful Emacs bindings are inherited from Tcl/Tk:
                Control-a     beginning of line
                Control-e     end of line
                Control-k     kill line (but doesn't put it in clipboard)
                Control-l     center window around the insertion point
        Standard keybindings (like Control-c to copy and Control-v to
        paste) may work.  Keybindings are selected in the Configure IDLE

Automatic indentation:

        After a block-opening statement, the next line is indented by 4 spaces
        (in the Python Shell window by one tab).  After certain keywords
        (break, return etc.) the next line is dedented.  In leading
        indentation, Backspace deletes up to 4 spaces if they are there.  Tab
        inserts spaces (in the Python Shell window one tab), number depends on
        Indent Width. Currently tabs are restricted to four spaces due
        to Tcl/Tk limitations.

        See also the indent/dedent region commands in the edit menu.


        Completions are supplied for functions, classes, and attributes of
        classes, both built-in and user-defined.  Completions are also provided
        for filenames.

        The AutoCompleteWindow (ACW) will open after a predefined delay
        (default is two seconds) after a '.' or (in a string) an os.sep is
        typed.  If after one of those characters (plus zero or more other
        characters) a tab is typed the ACW will open immediately if a possible
        continuation is found.

        If there is only one possible completion for the characters entered, a
        tab will supply that completion without opening the ACW.

        'Show Completions' will force open a completions window, by default the
        Control-space keys will open a completions window.  In an empty
        string, this will contain the files in the current directory.  On a
        blank line, it will contain the built-in and user-defined functions and
        classes in the current name spaces, plus any modules imported.  If some
        characters have been entered, the ACW will attempt to be more specific.

        If string of characters is typed, the ACW selection will jump to the
        entry most closely matching those characters. Entering a tab will cause
        the longest non-ambiguous match to be entered in the Edit window or
        Shell.  Two tabs in a row will supply the current ACW selection, as
        will return or a double click.  Cursor keys, Page Up/Down, mouse
        selection, and the scroll wheel all operate on the ACW.

        "Hidden" attributes can be accessed by typing the beginning of hidden
        name after a '.',  e.g. '_'.  This allows access to modules with
        '__all__' set, or to class-private attributes.

        Completions and the 'Expand Word' facility can save a lot of typing!

        Completions are currently limited to those in the namespaces.  Names in
        an Editor window which are not via __main__ or sys.modules will not be
        found.  Run the module once with your imports to correct this
        situation.  Note that IDLE itself places quite a few modules in
        sys.modules, so much can be found by default, e.g. the re module.

        If you don't like the ACW popping up unbidden, simply make the delay
        longer or disable the extension.  Or another option is the delay could
        be set to zero. Another alternative to preventing ACW popups is to
        disable the call tips extension.

Python Shell window:

        Control-c interrupts executing command.
        Control-d sends end-of-file; closes window if typed at >>> prompt.
        Alt-/ expand word is also useful to reduce typing.

    Command history:

        Alt-p retrieves previous command matching what you have typed. On OS X
        use Control-p.
        Alt-n retrieves next. On OS X use Control-n.
        Return while cursor is on a previous command retrieves that command.

    Syntax colors:

        The coloring is applied in a background "thread", so you may
        occasionally see uncolorized text.  To change the color
        scheme, use the Configure IDLE / Highlighting dialog.

    Python default syntax colors:

        Keywords        orange
        Builtins        royal purple
        Strings         green
        Comments        red
        Definitions     blue

    Shell default colors:

        Console output  brown
        stdout          blue
        stderr          red
        stdin           black

Other preferences:

        The font preferences, highlighting, keys, and general preferences can
        be changed via the Configure IDLE menu option.  Be sure to note that
        keys can be user defined, IDLE ships with four built in key sets. In
        addition a user can create a custom key set in the Configure IDLE
        dialog under the keys tab.

Command line usage:

        Enter idle -h at the command prompt to get a usage message. [-c command] [-d] [-e] [-s] [-t title] [arg] ...

        -c command  run this command
        -d          enable debugger
        -e          edit mode; arguments are files to be edited
        -s          run $IDLESTARTUP or $PYTHONSTARTUP first
        -t title    set title of shell window

        If there are arguments:
        1. If -e is used, arguments are files opened for editing and sys.argv
           reflects the arguments passed to IDLE itself.
        2. Otherwise, if -c is used, all arguments are placed in
           sys.argv[1:...], with sys.argv[0] set to -c.
        3. Otherwise, if neither -e nor -c is used, the first argument is a
           script which is executed with the remaining arguments in
           sys.argv[1:...]  and sys.argv[0] set to the script name.  If the
           script name is -, no script is executed but an interactive Python
           session is started; the arguments are still available in sys.argv.

Running without a subprocess: (DEPRECATED in Python 3.4 see Issue 16123)

        If IDLE is started with the -n command line switch it will run in a
        single process and will not create the subprocess which runs the RPC
        Python execution server.  This can be useful if Python cannot create
        the subprocess or the RPC socket interface on your platform.  However,
        in this mode user code is not isolated from IDLE itself.  Also, the
        environment is not restarted when Run/Run Module (F5) is selected.  If
        your code has been modified, you must reload() the affected modules and
        re-import any specific items (e.g. from foo import baz) if the changes
        are to take effect.  For these reasons, it is preferable to run IDLE
        with the default subprocess if at all possible.


        IDLE contains an extension facility.  See the beginning of
        config-extensions.def in the idlelib directory for further information.
        The default extensions are currently: