IDLE is Python’s Integrated Development and Learning Environment.
IDLE has the following features:
tkinter
GUI toolkit
IDLE has two main window types, the Shell window and the Editor window. It is possible to have multiple editor windows simultaneously. Output windows, such as used for Edit / Find in Files, are a subtype of edit window. They currently have the same top menu as Editor windows but a different default title and context menu.
IDLE’s menus dynamically change based on which window is currently selected. Each menu documented below indicates which window type it is associated with.
The clipboard functions are also available in context menus.
print
or
write
.
When execution is complete, the Shell retains focus and displays a prompt.
At this point, one may interactively explore the result of execution.
This is similar to executing a file with
python -i file
at a command
line.
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 (see below). On OS X, open the configuration dialog by selecting Preferences in the application menu. To use a new built-in color theme (IDLE Dark) with older IDLEs, save it as a new custom theme.
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.
The rest of this menu lists the names of all open windows; select one to bring it to the foreground (deiconifying it if necessary).
Additional help sources may be added here with the Configure IDLE dialog under the General tab.
Open a context menu by right-clicking in a window (Control-click on OS X). Context menus have the standard clipboard functions also on the Edit menu.
Editor windows also have breakpoint functions. Lines with a breakpoint set are specially marked. Breakpoints only have an effect when running under the debugger. Breakpoints for a file are saved in the user’s .idlerc directory.
Shell and Output windows have the following.
In this section, ‘C’ refers to the
Control
key on Windows and Unix and the
Command
key on Mac OSX.
Backspace
deletes to the left;
Del
deletes to the right
C-Backspace
delete word left;
C-Del
delete word to the right
Arrow keys and
Page Up
/
Page Down
to move around
C-LeftArrow
and
C-RightArrow
moves by words
Home
/
End
go to begin/end of line
C-Home
/
C-End
go to begin/end of file
Some useful Emacs bindings are inherited from Tcl/Tk:
C-a
beginning of line
C-e
end of line
C-k
kill line (but doesn’t put it in clipboard)
C-l
center window around the insertion point
C-b
go backwards one character without deleting (usually you can
also use the cursor key for this)
C-f
go forward one character without deleting (usually you can
also use the cursor key for this)
C-p
go up one line (usually you can also use the cursor key for
this)
C-d
delete next character
Standard keybindings (like
C-c
to copy and
C-v
to paste) may work. Keybindings are selected in the Configure IDLE dialog.
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
C-space
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 a 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 Editor window or Shell. Two
tab
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__
and
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.
A calltip is shown when one types
(
after the name of an
acccessible
function. A 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. When the cursor is in the argument part of a definition, the menu or shortcut display a calltip.
A calltip consists of the function signature and the first line of the docstring. For builtins without an accessible signature, the calltip consists of all lines up the fifth line or the first blank line. These details may change.
The set of accessible functions depends on what modules have been imported into the user process, including those imported by Idle itself, and what 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 import turtle. The menu or shortcut do nothing either. Enter
import turtle
and then
turtle.write(
will work.
In an editor, import statements have no effect until one runs the file. One might want to run a file after writing the import statements at the top, or immediately run an existing file before editing.
C-c
interrupts executing command
C-d
sends end-of-file; closes window if typed at a
>>>
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
C-p
.
Alt-n
retrieves next. On OS X use
C-n
.
Return
while on any previous command retrieves that command
Idle defaults to black on white text, but colors text with special meanings. For the shell, these are shell output, shell error, user output, and user error. For Python code, at the shell prompt or in an editor, these are keywords, builtin class and function names, names following
class
and
def
, strings, and comments. For any text window, these are the cursor (when present), found text (when possible), and selected text.
Text coloring is done in the background, so uncolorized text is occasionally visible. To change the color scheme, use the Configure IDLE dialog Highlighting tab. The marking of debugger breakpoint lines in the editor and text in popups and dialogs is not user-configurable.
Upon startup with the
-s
option, IDLE will execute the file referenced by the environment variables
IDLESTARTUP
or
PYTHONSTARTUP
. IDLE first checks for
IDLESTARTUP
；若
IDLESTARTUP
is present the file referenced is run. If
IDLESTARTUP
is not present, IDLE checks for
PYTHONSTARTUP
. Files referenced by these environment variables are convenient places to store functions that are used frequently from the IDLE shell, or for executing import statements to import common modules.
此外，
Tk
also loads a startup file if it is present. Note that the Tk file is loaded unconditionally. This additional file is
.Idle.py
and is looked for in the user’s home directory. Statements in this file will be executed in the Tk namespace, so this file is not useful for importing functions to be used from IDLE’s Python shell.
idle.py [-c command] [-d] [-e] [-h] [-i] [-r file] [-s] [-t title] [-] [arg] ... -c command run command in the shell window -d enable debugger and open shell window -e open editor window -h print help message with legal combinatios and exit -i open shell window -r file run file in shell window -s run $IDLESTARTUP or $PYTHONSTARTUP first, in shell window -t title set title of shell window - run stdin in shell (- must be last option before args)
If there are arguments:
-
,
-c
，或
r
is used, all arguments are placed in
sys.argv[1:...]
and
sys.argv[0]
被设为
''
,
'-c'
,
or
'-r'
. No editor window is opened, even if that is the default
set in the Options dialog.
sys.argv
reflects the arguments passed to IDLE itself.
As much as possible, the result of executing Python code with IDLE is the same as executing the same code in a console window. However, the different interface and operation occasionally affects results.
For instance, IDLE normally executes user code in a separate process from the IDLE GUI itself. The IDLE versions of sys.stdin, .stdout, and .stderr in the execution process get input from and send output to the GUI process, which keeps control of the keyboard and screen. This is normally transparent, but code that access these object will see different attribute values. Also, functions that directly access the keyboard and screen will not work.
With IDLE’s Shell, one enters, edits, and recalls complete statements. Some consoles only work with a single physical line at a time.
By default, IDLE executes user code in a separate subprocess via a socket, which uses the internal loopback interface. This connection is not externally visible and no data is sent to or received from the Internet. If firewall software complains anyway, you can ignore it.
If the attempt to make the socket connection fails, Idle will notify you. Such failures are sometimes transient, but if persistent, the problem may be either a firewall blocking the connecton or misconfiguration of a particular system. Until the problem is fixed, one can run Idle with the -n command line switch.
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.
Deprecated since version 3.4.
IDLE includes a help menu entry called “Python Docs” that will open the extensive sources of help, including tutorials, available at docs.python.org. Selected URLs can be added or removed from the help menu at any time using the Configure IDLE dialog. See the IDLE help option in the help menu of IDLE for more information.
The font preferences, highlighting, keys, and general preferences can be changed via Configure IDLE on the Option menu. 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.
IDLE contains an extension facility. Peferences for extensions can be changed with Configure Extensions. See the beginning of config-extensions.def in the idlelib directory for further information. The default extensions are currently:
25.4.
tkinter.scrolledtext
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