Alphametic puzzle brute force

puzzle.py

#!python
from itertools import permutations

def num(format, vals):
    return int("".join(str(vals[letter]) for letter in format))

letters = "eightrnwy "
def to_indices(word):
    return [letters.find(letter) for letter in word]

eight = to_indices("eight")
three = to_indices("three")
nine = to_indices("nine")
twenty = to_indices("twenty")

for a in permutations(range(10)):
    if num(eight, a) + num(three, a) + num(nine, a) == num(twenty, a):
        print dict(zip(letters, a))
        print num(eight, a), "+", num(three, a), "+", num(nine, a), "=", num(twenty, a)

@RocketPuppy I like it!