Python: Master the Art of Design Patterns

The principle of least knowledge

As you have learned in the initial parts of the chapter, the Façade provides a unified system that makes subsystems easy to use. It also decouples the client from the subsystem of components. The design principle that is employed behind the Façade pattern is the principle of least knowledge.

The principle of least knowledge guides us to reduce the interactions between objects to just a few friends that are close enough to you. In real terms, it means the following:

• When designing a system, for every object created, one should look at the number of classes that it interacts with and the way in which the interaction happens.
• Following the principle, make sure that we avoid situations where there are many classes created ...