cpython/Lib/idlelib/config-main.def

# IDLE reads several config files to determine user preferences.  This 
# file is the default config file for general idle settings.
#  
# When IDLE starts, it will look in
# the following two sets of files, in order:
#
#     default configuration
#     ---------------------
#     config-main.def         the default general config file
#     config-extensions.def   the default extension config file
#     config-highlight.def    the default highlighting config file
#     config-keys.def         the default keybinding config file
#
#     user configuration
#     -------------------
#     ~/.idlerc/idle-main.cfg            the user general config file
#     ~/.idlerc/idle-extensions.cfg      the user extension config file
#     ~/.idlerc/idle-highlight.cfg       the user highlighting config file
#     ~/.idlerc/idle-keys.cfg            the user keybinding config file
#
# Any options the user saves through the config dialog will be saved to
# the relevant user config file. Reverting any general setting to the 
# default causes that entry to be wiped from the user file and re-read 
# from the default file. User highlighting themes or keybinding sets are
# retained unless specifically deleted within the config dialog. Choosing
# one of the default themes or keysets just applies the relevant settings 
# from the default file. 

[General]
editor-on-startup= 1
user-help-browser= 0
user-help-browser-command= 

[EditorWindow]
width= 80
height= 30
font= courier
font-size= 12
font-bold= 0

[Indent]
use-spaces= 1
num-spaces= 4

[Theme]
default= 1  
name= IDLE Classic

[Keys]
default= 1  
name= IDLE Classic Windows

[HelpFiles]
#additional help sources, must be viewable by an html browser
#will be listed on the Help/Other Help menu
#option names are the sequence number of the option
#values take the form: menu item;/path/to/help/source
#obviously you can't use a semi-colon in a menu item or path and the path will 
#be platform specific because of path separators, drive specs etc. 
#eg.:
#1= My Extra Help Source;/usr/share/doc/foo/index.html
#2= Another Help Source;/path/to/another.html

#[RecentFiles]
#this section will only be present in the user config file idle-main.cfg
#where it will record the most recently openned files in the form
#IndexNum= /full/path/of/file  , for display on the File/Recent Files menu
#it is present here for reference only
#eg.:
#1=/most/recently/openned/file
#2=/next/most/recently/openned/file
#etc.