Marionette is the library integrated in specific builds used for unit testing in Firefox. Using Python enables to automatize procedure or other stuff using the browser also in headless mode. Let's see how it is possible to simplify your daily job routine on internet like a pro. Often there are tasks that are easily to automatize with scripting but this portal/website doesn't offer API. Develop a browser extension only for an internal usage can be an over engineering step but there is another way. Python is a powerful language and we can use it also to integrate in other services or to help a community. There will 2 real cases: how to export WordPress posts without having advanced backend permissions to reimport it later and how to automatize the reject of bad translation in the WordPress community based on terms.