ZERO / HERO
Children of the blueprint

Inheritance as Genetics

The analogy

A Townhouse is a House — it inherits the walls, the roof and the front door without redrawing them, then adds a shared side wall of its own. Like a child inheriting eye colour: you get the family traits for free, plus whatever is uniquely yours.

Visualizer

Traits flowing down the family

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HouseTownhouseCottageStudioFlat

One parent class, two children, one grandchild.House declares: openDoor(), windows, address

class House:
    def open_door(self):
        return "creak"

class Townhouse(House):   # inherits everything
    pass

class Cottage(House):
    pass

Townhouse().open_door()   # "creak" — for free
Check yourself

Townhouse extends House. Does Townhouse have House's openDoor()?