Configuration in Python Applications: No Magic, Just Necessary Practice

Link: Configuration in Python Applications: No Magic, Just Necessary Practice: "During the development of Python applications, I've continually asked myself how and when variables should be passed and initialized for the application's configuration. I want to be able to easily override the configuration for tests, for example, to use a local database for testing. But what exactly is application configuration, and why is it needed? The website a ..."