load stop words

def _load_stopwords(file_path):
    '''
    load stop words
    '''
    global _stopwords
    if sys.version_info[0] < 3:
        words = open(file_path, 'r')
    else:
        words = open(file_path, 'r', encoding='utf-8')
    stopwords = words.readlines()
    for w in stopwords:
        _stopwords.add(any2unicode(w).strip())