如何拆分python字符串中某个字符之前最后一个单词，并替换txt文件中的同一行？

def split_and_replace(file_path, character):
    # 读取txt文件内容
    with open(file_path, 'r') as file:
        lines = file.readlines()

    # 遍历每一行内容
    for i in range(len(lines)):
        line = lines[i].strip()

        # 拆分字符串并替换
        words = line.split()
        if character in line:
            index = words.index(character)
            last_word = ' '.join(words[:index])
            line = line.replace(words[index-1], last_word)

        # 更新列表中的内容
        lines[i] = line

    # 将更新后的内容写回txt文件
    with open(file_path, 'w') as file:
        file.writelines(lines)

# 示例调用
split_and_replace('example.txt', ',')