But this is just half of the story, OOP is much more powerful. We have two main design constructs to exploit: inheritance and composition.
Inheritance means that two objects are related by means of an Is-A type of relationship. On the other hand, composition means that two objects are related by means of a Has-A type of relationship. It's all very easy to explain with an example:
# oop/class_inheritance.pyclass Engine: def start(self): pass def stop(self): passclass ElectricEngine(Engine): # Is-A Engine passclass V8Engine(Engine): # Is-A Engine passclass Car: engine_cls = Engine def __init__(self): self.engine = self.engine_cls() # Has-A Engine def start(self): print( 'Starting engine {0} for car {1}... Wroom, ...
