I am developing a piece of software in python that will be distributed to my employer's customers. My employer wants to limit the usage of the software with a time restricted license file.

If we distribute the .py files or even .pyc files it will be easy to (decompile), and remove the code that checks the license file.

Another aspect is that my employer do not want the code to be read by our customers, fearing that the code may be stolen or at least the "novel ideas".

Is there a good way to handle this problem? Preferably with an off-the-shelf solution.

The software will run on Linux systems (so I don't think py2exe will do the trick)