best_word_lock.py

#!/usr/bin/env python3.4
# A response to http://nbviewer.ipython.org/url/norvig.com/ipython/Fred%20Buns.ipynb
# Read more about it at https://blog.glyphobet.net/essay/2770
import itertools
from collections import Counter

lock_size = 10
WORDS = set(w.lower() for w in open('words4.txt').read().split())

norvig_improved_wordlock = ['spcmthdlfb', 'leyhwruoai', 'enmlrtacso', 'dsnpaylkte']
norvig_improved_random =  ['dwbfptlmsc', 'aohryuiwel', 'atocsinerl', 'eyadhstlnk']

cat = ''.join

def combinations(lock):
    "Return a list of all combinations that can be made by this lock."
    return set(map(cat, itertools.product(*lock)))

def words_from(lock):
    "A list of words that can be made by lock."
    return [c for c in combinations(lock) if c in WORDS]

def word_count(lock):
    return len(words_from(lock))

def print_common(counters, depth=12):
    most_commons = [c.most_common(depth) for c in counters]
    for row in zip(*most_commons):
        for col in row:
            print('{}:{}'.format(*col), end='\t')
        print()

def print_lock(lock):
    print("Lock: " + ' '.join((''.join(sorted(t))).upper() for t in lock), end='')
    print(',', word_count(lock), 'words')

def main():

    for l in (norvig_improved_wordlock, norvig_improved_random):
        print_lock(l)

    counters = [Counter(), Counter(), Counter(), Counter()]
    for word in WORDS:
        word = word.lower().strip()
        for i,c in enumerate(word):
            counters[i][c] += 1

    lock = ['', '', '', '']

    while min(len(l) for l in lock) < 10:
        # print_common(counters)
        best_count = 0
        best_index = None
        best_letter = None
        for i, c in enumerate(counters):
            if len(lock[i]) >= lock_size:
                continue
            letter, count = c.most_common(1)[0]
            if (best_count < count):
                best_count = count
                best_index = i
                best_letter = letter
        print("Best choice is {}:{} at index {}".format(best_letter, best_count, best_index))
        del counters[best_index][best_letter]
        lock[best_index] += best_letter
        # print_lock(lock)

    print_lock(lock)


if __name__ == '__main__':
    main()