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 combinations 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)
如果有参数：
If -, -c, or r is used, all arguments are placed in
sys.argv[1:...] and sys.argv[0] is set to '', '-c',
or '-r'.  No editor window is opened, even if that is the default
set in the Options dialog.
Otherwise, arguments are files opened for editing and
sys.argv reflects the arguments passed to IDLE itself.
启动失败¶
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
displays a Tk error box with a 'cannot connect' message that directs the
user here.  It then exits.
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.
运行用户代码¶
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.activeCount() 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.
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.
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.  The secondary subprocess
will then be attached to that window for input and output.
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.
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 user code raises SystemExit either directly or by calling sys.exit, IDLE
returns to a Shell prompt instead of exiting.
Shell中的用户输出¶
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)
>>> 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.
开发 tkinter 应用程序¶
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.
在没有子进程的情况下运行¶
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 connection 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.
3.4 版后已移除.
帮助源¶
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.
首选项设置¶
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.
macOS 上的IDLE¶
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.
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.