[{"user_name": "liushui", "psw": "123456", "mail": "123456@163.com"}, {"user_name": "liushui0", "psw": "12345", "mail": "123@qq.com"}, {"user_name": "liushui1", "psw": "123", "mail": "123456@qq.com"}, {"user_name": "liushui11", "psw": "123456", "mail": "897564"}]
values（） 转list这种方法不需要导入方法，使用values方法获取一个可迭代的dict序列，在使用list函数转成list对象