One often needs an embedded, persistent, key-store database solution if he/she is developing a software which relies on configurations made upon deployment. I was that one yesterday, so I looked up on the Internet for a solution. The solution was, with no convincing reason, Berkeley DB Java Edition, Sleepy Cat to be specific.
So here is the code chunk that did the trick! For a developer of modern languages like Python, it seemed like a lot of work for simple tasks. However, if you wrap it with your own code it can be helpful in many ways.