app.py

from flask import Flask, render_template,url_for,request

import re
from collections import Counter

def words(document):
    "Convert text to lower case and tokenize the document"
    return re.findall(r'\w+', document.lower())

# create a frequency table of all the words of the document
all_words = Counter(words(open('big.txt').read()))

def edits_one(word):
    "Create all edits that are one edit away from `word`."
    alphabets    = 'abcdefghijklmnopqrstuvwxyz'
    splits     = [(word[:i], word[i:])                   for i in range(len(word) + 1)]
    deletes    = [left + right[1:]                       for left, right in splits if right]
    inserts    = [left + c + right                       for left, right in splits for c in alphabets]
    replaces   = [left + c + right[1:]                   for left, right in splits if right for c in alphabets]
    transposes = [left + right[1] + right[0] + right[2:] for left, right in splits if len(right)>1]
    return set(deletes + inserts + replaces + transposes)

def edits_two(word):
    "Create all edits that are two edits away from `word`."
    return (e2 for e1 in edits_one(word) for e2 in edits_one(e1))

def known(words):
    "The subset of `words` that appear in the `all_words`."
    return list(word for word in words if word in all_words)

def possible_corrections(word):
    "Generate possible spelling corrections for word."
    suggested_words = (known([word]) or known(edits_one(word)) or known(edits_two(word)) or [word])
    return list(suggested_words)

def prob(word, N=sum(all_words.values())): 
    "Probability of `word`: Number of appearances of 'word' / total number of tokens"
    return all_words[word] / N

def rectify(word):
    "return the most probable spelling correction for `word` out of all the `possible_corrections`"
    correct_word = max(possible_corrections(word), key=prob)
    return correct_word

app = Flask(__name__)

@app.route('/')
@app.route('/home')
def home():
    return render_template('home.html')

@app.route('/recommend')
def recommend():
    message = request.args.get('word')
    message = str(message)
    r=possible_corrections(message)
    if ''.join(r) == message:
        return render_template('recommend.html',x=message,r=r,t='s')
    else:
        return render_template('recommend.html',x=message,r=r,t='suggested_words')


if __name__ ==  '__main__':
    app.run(debug=True)