python 自定义文件类型

一直在找python 自定义文件类型，用来保存敏感数据，现在终于找到一个比较满意的了。
直接上代码

import  pickle

li = ["nihao","haloo",{"sdf":123}]

with open("test.xxx","wb") as fb:
    pickle.dump(li,fb)

with open("test.xxx","rb") as fb:
    ss=pickle.load(fb)
    print(type(ss),ss,type(ss[2]["sdf"]))

生成 文件test.xxx
查询结果是

<class 'list'> ['nihao', 'haloo', {'sdf': 123}] <class 'int'>