Most complex software applications need some form of configuration, often through a configuration file. The more complicated the app, the more difficult become the choices between offering flexibility and improving usability. Configuration is the solution to get the best of both worlds. However, getting it right takes knowledge, experience and discipline and often requires having made all the usual mistakes yourself and learned from them. Now, our team of developers and data-analysts has published their solution to this problem as an open-source python library: PyConfig.