AutoCompleter.py

from __future__ import print_function

import sys
import readline
from os import environ


class AutoCompleter(object):  # Custom completer

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

    def complete(self, text, state):
        if state == 0:  # on first trigger, build possible matches
            if not text:
                self.matches = self.options[:]
            else:
                self.matches = [s for s in self.options
                                if s and s.startswith(text)]

        # return match indexed by state
        try:
            return self.matches[state]
        except IndexError:
            return None

    def display_matches(self, substitution, matches, longest_match_length):
        line_buffer = readline.get_line_buffer()
        columns = environ.get("COLUMNS", 80)

        print('\n')

        tpl = "{:<" + str(int(max(map(len, matches)) * 1.2)) + "}"

        buffer = ""
        for match in matches:
            match = tpl.format(match[len(substitution):])
            if len(buffer + match) > columns:
                print(buffer)
                buffer = ""
            buffer += match

        if buffer:
            print(buffer)

        print(self.prefix, end="")
        print(line_buffer, end="")
        sys.stdout.flush()