def tf_matrix(self, sent_word_freq_table) -> dict:
    tf_matrix = {}
    for (sent, word_freq_table) in sent_word_freq_table.items():
        tf_table = {}
        sent_word_count = len(word_freq_table)
        for (word, freq) in word_freq_table.items():
            tf_table[word] = (freq / sent_word_count)
        tf_matrix[sent] = tf_table
    return tf_matrix
def tf_matrix(self, sent_word_freq_table) -> dict:
    tf_matrix = {}
    for (sent, word_freq_table) in sent_word_freq_table.items():
        tf_table = {}
        sent_word_count = len(word_freq_table)
        for (word, freq) in word_freq_table.items():
            tf_table[word] = (freq / sent_word_count)
        tf_matrix[sent] = tf_table
    return tf_matrix