Tab completion of keywords in specific order

Question

I am using the following code for tab completion in my program

import readline
import logging
import sys

LOG_FILENAME = '/tmp/completer.log'
logging.basicConfig(filename=LOG_FILENAME,
                    level=logging.DEBUG,
                    )

class SimpleCompleter(object):

    def __init__(self, options):
        self.options = sorted(options)
        return

    def complete(self, text, state):
        response = None
        if state == 0:
            # This is the first time for this text, so build a match list.
            if text:
                self.matches = [s
                                for s in self.options
                                if s and s.startswith(text)]
                logging.debug('Text: %s', text)
                logging.debug('%s matches: %s', repr(text), self.matches)
            else:
                self.matches = self.options[:]
                logging.debug('(empty input) matches: %s', self.matches)

        # Return the state'th item from the match list,
        # if we have that many.
        try:
            response = self.matches[state]
        except IndexError:
            response = None
        logging.debug('complete(%s, %s) => %s',
                      repr(text), state, repr(response))
        return response

def input_loop():
    line = ''
    while line != 'stop':
        line = input('>')
        print('Dispatch %s' % line)

# Register our completer function
readline.set_completer(SimpleCompleter(['CREATE', 'INPUT', 'USERNAME', 'VIEW']+ [account_names]).complete)

# Use the tab key for completion
readline.parse_and_bind('tab: complete')

# Prompt the user for text
input_loop()

However the code accepts keywords in any order, how can I change it so that keywords are processed in a specific order. For example if the first keyword is CREATE next tab completion shouldn't find any matches and allow for user to input an account name. Similarly if the first keyword is INPUT next it should match USERNAME or PASSWORD and then account name. Is it possible to do this with readline?

Answer 1

readline.get_line_buffer() gets the whole buffered text from which you can create the matches as required.