defaultinput.py

import readline

def make_hook(text):
    def _hook():
        readline.insert_text(text)
        readline.redisplay()
    return _hook

readline.set_pre_input_hook(make_hook(''))

while True:
    line = raw_input('> ')
    if line == "quit":
        break
    readline.set_pre_input_hook(make_hook(line))
    print "you entered '%s'" % line