from dataclasses import dataclass


@dataclass(frozen=True)
class Konto:
    inhaber: str
    saldo: float

    def __init__(self, inhaber: str, saldo: float):
        if not inhaber:
            raise ValueError("inhaber is required")
        if saldo < 0:
            raise ValueError("saldo must be positive")
        object.__setattr__(self, "inhaber", inhaber)
        object.__setattr__(self, "saldo", saldo)

    def einzahlen(self, betrag: float):
        object.__setattr__(self, "saldo", self.saldo + betrag)

    def abheben(self, betrag: float):
        object.__setattr__(self, "saldo", self.saldo - betrag)
        return betrag


k1 = Konto("Alice", 100.0)
k2 = Konto("Housi", 10)
k2.einzahlen(100)

print(k1.inhaber)
print(k2.saldo)
print(k1 is k2)
print(k1)