get word2vec data by sentence
    sentence is segmented string.

def _get_wv(sentence, ignore=False):
    '''
    get word2vec data by sentence
    sentence is segmented string.
    '''
    global _vectors
    vectors = []
    for y in sentence:
        y_ = any2unicode(y).strip()
        if y_ not in _stopwords:
            syns = nearby(y_)[0]
            # print("sentence %s word: %s" %(sentence, y_))
            # print("sentence %s word nearby: %s" %(sentence, " ".join(syns)))
            c = []
            try:
                c.append(_vectors.word_vec(y_))
            except KeyError as error:
                if ignore:
                    continue
                else:
                    logging.warning("not exist in w2v model: %s" % y_)
                    # c.append(np.zeros((100,), dtype=float))
                    random_state = np.random.RandomState(seed=(hash(y_) % (2**32 - 1)))
                    c.append(random_state.uniform(low=-10.0, high=10.0, size=(100,)))
            for n in syns:
                if n is None: continue
                try:
                    v = _vectors.word_vec(any2unicode(n))
                except KeyError as error:
                    # v = np.zeros((100,), dtype=float)
                    random_state = np.random.RandomState(seed=(hash(n) % (2 ** 32 - 1)))
                    v = random_state.uniform(low=10.0, high=10.0, size=(100,))
                c.append(v)
            r = np.average(c, axis=0)
            vectors.append(r)
    return vectors