从.txt文件中删除整个单词，但当单词显示为子字符串时不删除

def delete_words_from_file(file_path, substring):
    # 读取.txt文件
    with open(file_path, 'r') as file:
        content = file.read()

    # 分割文件内容为单词列表
    words = content.split()

    # 遍历单词列表
    for word in words[:]:
        # 判断单词是否为子字符串
        if substring not in word:
            # 删除整个单词
            words.remove(word)

    # 重新构建文本内容
    new_content = ' '.join(words)

    # 写入.txt文件
    with open(file_path, 'w') as file:
        file.write(new_content)

# 调用函数删除单词
delete_words_from_file('example.txt', 'substring')