def get_tfidf_score(tf_vocab, idf_vocab):
    """Calculate the tfidf score for an article
    :param tf_vocab: a dict that maps a word into its tf value
    :param idf_vocab: a dict that maps a word into its idf value
    :returns: a list of tuple, where the first element is the word,
              the second element is its tf-idf score.
    :rtype: a list of (str, float)
    """

    scores = []
    for word in tf_vocab:
        tfidf = tf_vocab[word] * idf_vocab.get(word, 0)
        scores.append([word, tfidf])
    scores = sorted(scores, key=lambda x: x[1], reverse=True)
    return scores