def set_completer(completionfunction = None):
    class DerivedCompleter (ReadlineCompleter):
        def __init__ (self, method):
             self.method = method

        def completer (self, text, state):
             return self.method(text, state)

    Readline.setCompleter(DerivedCompleter(completionfunction))
Set or remove the completer instance. If an instance of ReadlineCompleter is specified, 
dataset/ETHPy150Open babble/babble/include/jython/Lib/readline.py/set_completer