Hi there
This can be done in two ways. Setup lightweight server that will your extension be communicating with, since browsers don't have big API permissions with OS (for security reasons), or the second way, that is by using nativeMessaging API from Chrome. You can designate a Native Host application that an extension or app will be able to invoke (probably through a background page in case of an extension), and that can be a Python script.
Anyways, feel free to hit me up so we can talk more about this. I am very responsive, and the price is negotiable. All the best in 2019 :)