Licensing of programs made in Python

From the legal point of view, you can do as you wish, the software is yours and no one can say anything as you will distribute it. The only restriction is if you use codes in your application that require you to distribute it openly, but it has nothing to do with the language.

The term used "open programming language" is wrong. This does not exist. The implementation of the language has open source. And the code you produce gets exposed. Just this.

From the technical point of view, the language does not help protect the code. There are code obfuscation techniques that help. This is not part of the focus of this question but I quoted some in another question . There are others.

I do not know if I understand, but if you want to develop an operating system with Python, you are in a very wrong way.