SpellCheck.py

import sys
import re
from collections import Counter
def words(text): return re.findall(r'\w+', text.lower())

WORDS = Counter(words(open('/home/amitd92/Desktop/Git/nodeJs/big.txt').read()))

def P(word, N=sum(WORDS.values())):
    "Probability of `word`."
    return float(float(WORDS[word]) / float(N))

def correction(word):
    "Most probable spelling correction for word."
    if word.strip()=="":
        return " "

    a = candidates(word)
    return max(a, key=P)

def candidates(word):
    "Generate possible spelling corrections for word."

    return (known([word])  or known(edits1(word)) or known(edits2(word)) or [word])

def known(words):
    "The subset of `words` that appear in the dictionary of WORDS."
    return set(w for w in words if w in WORDS)

def edits1(word):
    "All edits that are one edit away from `word`."
    letters    = 'abcdefghijklmnopqrstuvwxyz'
    splits     = [(word[:i], word[i:])    for i in range(len(word) + 1)]
    deletes    = [L + R[1:]               for L, R in splits if R]
    transposes = [L + R[1] + R[0] + R[2:] for L, R in splits if len(R)>1]
    replaces   = [L + c + R[1:]           for L, R in splits if R for c in letters]
    inserts    = [L + c + R               for L, R in splits for c in letters]
    return set( inserts+replaces +deletes + transposes)

def edits2(word):
    "All edits that are two edits away from `word`."
    return (e2 for e1 in edits1(word) for e2 in edits1(e1))

def edits3(word):
    "All edits that are two edits away from `word`."
    return (e2 for e1 in edits2(word) for e2 in edits2(e1))

s=""
print correction(" ")
sys.stdout.flush()