pythonrc

import atexit
import os.path

try:
   import readline
except ImportError:
   pass
else:
   import rlcompleter

   class IrlCompleter(rlcompleter.Completer):
       """
       This class enables a "tab" insertion if there's no text for
       completion.

       The default "tab" is four spaces. You can initialize with '\t' as
       the tab if you wish to use a genuine tab.

       """

       def __init__(self, tab='    '):
           self.tab = tab
           rlcompleter.Completer.__init__(self)


       def complete(self, text, state):
           if text == '':
               readline.insert_text(self.tab)
               return None
           else:
               return rlcompleter.Completer.complete(self,text,state)


   #you could change this line to bind another key instead tab.
   readline.parse_and_bind('tab: complete')
   readline.set_completer(IrlCompleter().complete)


# Restore our command-line history, and save it when Python exits.
history_path = os.path.expanduser('~/.pyhistory')
if os.path.isfile(history_path):
   readline.read_history_file(history_path)
atexit.register(lambda x=history_path: readline.write_history_file(x))