在子类中生成字符串实现

class Animal:
    def __init__(self, name):
        self.name = name

    def __str__(self):
        return f"Animal: {self.name}"

class Dog(Animal):
    def __init__(self, name, breed):
        super().__init__(name)
        self.breed = breed

    def __str__(self):
        return f"Dog: {self.name}, Breed: {self.breed}"

animal = Animal("Tom")
print(animal)  # 输出: Animal: Tom

dog = Dog("Max", "Labrador")
print(dog)  # 输出: Dog: Max, Breed: Labrador