如何使用两个向量打印给定输入字符串中每个单词的频率？

def print_word_frequency(input_string):
    # 分词
    words = input_string.split()

    # 创建单词向量和频率向量
    word_vector = []
    frequency_vector = []

    # 统计频率
    for word in words:
        if word in word_vector:
            index = word_vector.index(word)
            frequency_vector[index] += 1
        else:
            word_vector.append(word)
            frequency_vector.append(1)

    # 打印输出
    for i in range(len(word_vector)):
        print("单词: ", word_vector[i])
        print("频率: ", frequency_vector[i])

# 测试
input_string = "I love programming. Programming is fun!"
print_word_frequency(input_string)

单词:  I
频率:  1
单词:  love
频率:  1
单词:  programming.
频率:  1
单词:  Programming
频率:  1
单词:  is
频率:  1
单词:  fun!
频率:  1