如何仅用1个所需输出替换字典中列表中的字符串

def replace_strings_in_dict(dictionary, output):
    for key, value in dictionary.items():
        if isinstance(value, list):
            # 列表推导式替换字符串
            dictionary[key] = [str_.replace('原字符串', output) for str_ in value]
    return dictionary

# 示例字典
my_dict = {
    'key1': ['字符串1', '字符串2'],
    'key2': '字符串3',
    'key3': ['字符串4', '字符串5', '字符串6']
}

# 替换字符串为所需输出
result_dict = replace_strings_in_dict(my_dict, '所需输出')

# 输出替换后的字典
print(result_dict)