stop_words = set(stopwords.words('english'))
for i in range(len(df.words)) :
    s = df.words[i]
    # table = s.maketrans('', '', string.punctuation)
    # s = s.translate(table)
    # df.words[i] = s
    sentence = s.lower()  # Converting to lowercase
    cleanr = re.compile('<.*?>')
    sentence = re.sub(cleanr, ' ', sentence)  # Removing HTML tags
    sentence = re.sub(r'[?|!|\'|"|#]', r'', sentence)
    sentence = re.sub(r'[.|,|)|(|\|/]', r' ', sentence)  # Removing Punctuations

    tokens = word_tokenize(sentence)
    result = [i for i in tokens if not i in stop_words]

    df.words[i] = ' '.join(result)