ZERO / HERO
Walls and a doorbell

Encapsulation

The analogy

You do not climb through a stranger's window to ask a question — you ring the doorbell. The house decides what to show you. Encapsulation means the messy insides are private, and the doorbell (a public method) is the only agreed way in.

Visualizer

Walls and a doorbell

step 1 / 7
INSIDE THE WALLS — private
#wiring
#plumbing
#safeCode = "4821"
THE DOORBELL — public
ringBell()
requestEntry(name)

Private things behind the wall. Public things on the porch.

class House:
    def __init__(self):
        self.__safe_code = "4821"   # name-mangled

    def ring_bell(self):            # public
        return "who is it?"

h = House()
h.ring_bell()      # fine
h.__safe_code      # AttributeError
Check yourself

Why make a field private?