python中的单词频率程序

def word_frequency(text):
    # 将文本转换为小写，并去除标点符号
    text = text.lower()
    text = text.replace(",", "").replace(".", "").replace("!", "").replace("?", "")

    # 分割文本为单词列表
    words = text.split()

    # 统计每个单词的出现次数
    frequency = {}
    for word in words:
        if word in frequency:
            frequency[word] += 1
        else:
            frequency[word] = 1

    # 按照单词出现次数降序排序
    sorted_frequency = sorted(frequency.items(), key=lambda x: x[1], reverse=True)

    return sorted_frequency