sentence segment

def cut_sentence_new(words):
    words = (words).decode('utf8')
    start = 0
    i = 0
    sents = []
    # print words
    token = list(words[start:i+2]).pop() 
    punt_list = '.!?;~。！？；～'.decode('utf8')
    for word in words:
        if word in punt_list and token not in punt_list: 
            sents.append(words[start:i+1])
            start = i+1
            i += 1
        else:
            i += 1
            token = list(words[start:i+2]).pop() 
    if start < len(words):
        sents.append(words[start:])
    return sents