python corrector

http://norvig.com/spell-correct.html

import re, collectionsdef words(text): return re.findall('[a-z]+', text.lower()) def train(features):    model = collections.defaultdict(lambda: 1)    for f in features:        model[f] += 1    return modelNWORDS = train(words(file('big.txt').read()))alphabet = 'abcdefghijklmnopqrstuvwxyz'def edits1(word):   splits     = [(word[:i], word[i:]) for i in range(len(word) + 1)]   deletes    = [a + b[1:] for a, b in splits if b]   transposes = [a + b[1] + b[0] + b[2:] for a, b in splits if len(b)>1]   replaces   = [a + c + b[1:] for a, b in splits for c in alphabet if b]   inserts    = [a + c + b     for a, b in splits for c in alphabet]   return set(deletes + transposes + replaces + inserts)def known_edits2(word):    return set(e2 for e1 in edits1(word) for e2 in edits1(e1) if e2 in NWORDS)def known(words): return set(w for w in words if w in NWORDS)def correct(word):    candidates = known([word]) or known(edits1(word)) or known_edits2(word) or [word]    return max(candidates, key=NWORDS.get)

The code defines the function correct, which takes a word as input and returns a likely correction of that word. For example:

>>> correct('speling')'spelling'>>> correct('korrecter')'corrector'