class User:
    def __init__(self, id, name, pin="4242") -> None:
        self.id = id
        self.name = name
        self.debt = 0.0
        self.pin = pin

    def to_json(self):
        return {"id": self.id, "name": self.name, "debt": self.debt, "pin": self.pin}

    @staticmethod
    def from_json(data):
        pin = data.get("pin")
        if pin is None:
            pin = "4242"
        user = User(data["id"], data["name"], pin)
        user.debt = data["debt"]
        return user