Secure deploy the code without providing the implementation

[mikepy]

Hi fellows, how can I deploy my own library created in Python on Windows or Linux without providing the source code. The reason is that I want to use it in future as production code. So in my case I would only like to provide the function or method delarations and not the implementation. How can I achieve this security deployment? I know that there is a pyc file which encrypts the code, but I have read that it is possible with some expense to dencrypt it. That is not what I need.