from structural.facade.subsystems import Subsystem1, Subsystem2 class Facade: """ The Facade class provides a simple interface to the complex logic of one or several subsystems. The Facade delegates the client requests to the appropriate objects within the subsystem. The Facade is also responsible for managing their lifecycle. All of this shields the client from the undesired complexity of the subsystem. """ def __init__(self, subsystem1: Subsystem1, subsystem2: Subsystem2) -> None: """ Depending on your application's needs, you can provide the Facade with existing subsystem objects or force the Facade to create them on its own. """ self._subsystem1 = subsystem1 or Subsystem1() self._subsystem2 = subsystem2 or Subsystem2() def operation(self) -> str: """ The Facade's methods are convenient shortcuts to the sophisticated functionality of the subsystems. However, clients get only to a fraction of a subsystem's capabilities. """ results = [ "Facade initializes subsystems:", self._subsystem1.operation1(), self._subsystem2.operation1(), "Facade orders subsystems to perform the action:", self._subsystem1.operation_n(), self._subsystem2.operation_z(), ] return "\n".join(results)