Python:仅允许设置具有@property修饰符的属性

class Person:
    def __init__(self, name):
        self._name = name

    @property
    def name(self):
        return self._name

person = Person("John")
print(person.name)  # 输出：John
person.name = "Mike"  # 抛出AttributeError异常，无法修改只读属性

class Circle:
    def __init__(self, radius):
        self._radius = radius

    @property
    def radius(self):
        return self._radius

    @property
    def area(self):
        return 3.14 * self.radius * self.radius

circle = Circle(5)
print(circle.radius)  # 输出：5
print(circle.area)  # 输出：78.5

class Person:
    def __init__(self, age):
        self._age = age

    @property
    def age(self):
        return self._age

    @age.setter
    def age(self, value):
        if value < 0:
            raise ValueError("Age cannot be negative")
        self._age = value

person = Person(25)
print(person.age)  # 输出：25
person.age = 30
print(person.age)  # 输出：30
person.age = -5  # 抛出ValueError异常，年龄不能为负数