1.编写一个圆类，圆类有半径Radius和圆心心center等属性，这些属性可以查看get 也可以重新设置set,另外还可以统计圆的个数，返回其面积及周长。 2.编写一个圆环类 Ring。圆环类有内半径innerRadius,外半径outerRadius和圆心center等属性,这些属性可以查看get 也可以重新设置set,另外，圆环还可以返回其面积及外周长。 3.创建圆环类的对象，并输出对象的面积和周长;创建多个圆，输出总的个数，每个圆的面积周长等。

1. 圆类的代码如下：

class Circle:
    def __init__(self, radius, center):
        self.radius = radius
        self.center = center
        Circle.count += 1

    count = 0

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

    @radius.setter
    def radius(self, value):
        if value < 0:
            raise ValueError("Radius cannot be negative")
        self._radius = value

    @property
    def center(self):
        return self._center

    @center.setter
    def center(self, value):
        self._center = value

    def area(self):
        return 3.14 * self.radius ** 2

    def perimeter(self):
        return 2 * 3.14 * self.radius

2. 圆环类的代码如下：

class Ring:
    def __init__(self, inner_radius, outer_radius, center):
        self.inner_radius = inner_radius
        self.outer_radius = outer_radius
        self.center = center
        Ring.count += 1

    count = 0

    @property
    def inner_radius(self):
        return self._inner_radius

    @inner_radius.setter
    def inner_radius(self, value):
        if value < 0:
            raise ValueError("Inner radius cannot be negative")
        self._inner_radius = value

    @property
    def outer_radius(self):
        return self._outer_radius

    @outer_radius.setter
    def outer_radius(self, value):
        if value < 0:
            raise ValueError("Outer radius cannot be negative")
        self._outer_radius = value

    @property
    def center(self):
        return self._center

    @center.setter
    def center(self, value):
        self._center = value

    def area(self):
        return 3.14 * (self.outer_radius ** 2 - self.inner_radius ** 2)

    def perimeter(self):
        return 2 * 3.14 * (self.outer_radius + self.inner_radius)

3. 创建圆环类的对象并输出面积和周长的代码如下：

ring = Ring(3, 5, (0, 0))
print("Ring area:", ring.area())
print("Ring perimeter:", ring.perimeter())

创建多个圆并输出总个数、每个圆的面积和周长的代码如下：

c1 = Circle(2, (0, 0))
c2 = Circle(3, (1, 1))
c3 = Circle(4, (2, 2))
print("Total circles:", Circle.count)
print("Circle 1 area:", c1.area())
print("Circle 1 perimeter:", c1.perimeter())
print("Circle 2 area:", c2.area())
print("Circle 2 perimeter:", c2.perimeter())
print("Circle 3 area:", c3.area())
print("Circle 3 perimeter:", c3.perimeter())