def read_tokenized_trg_file(path):
    """
    read tokenized target text file and convert them to list of list of words
    :param path:
    :return: data, a 3d list, each item in the list is a list of target, each target is a list of words.
    """
    data = []
    with open(path) as f:
        for line in f:
            trg_list = line.strip().split(';') # a list of target sequences
            trg_word_list = [trg.split(' ') for trg in trg_list]
            data.append(trg_word_list)
    return data