用python 定义基本几何图形类Shape，Shape类的对象方法有：求面积方法 area(); 求周长方法 length(); 球体积方法 volume(); 输出图形的信息方法toString( )。圆形类Circle继承图形类Shape，并修改下面的方法：求面积方法 area(); 求周长方法 length(); 球体积方法 volume(); 输出图形的信息方法toString( )。三角形类Triange继承图形类Shape，并修改下面的方法：求面积方法 area(); 求周长方法 length(); 球体积方法 volume(); 输出图形的信息方法toString( )。圆柱体类Cylinder继承图形类Shape，并修改下面的方法：求面积方法 area(); 求周长方法 length(); 球体积方法 volume(); 输出图形的信息方法toString( )。上面的类都有构造函数。最后每个类都创建一个对象，并调用这些对象的toString( )方法

好的，以下是代码实现：

import math

class Shape:
    def __init__(self):
        pass

    def area(self):
        pass

    def length(self):
        pass

    def volume(self):
        pass

    def toString(self):
        pass

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

    def area(self):
        return math.pi * self.radius ** 2

    def length(self):
        return 2 * math.pi * self.radius

    def volume(self):
        return 4/3 * math.pi * self.radius ** 3

    def toString(self):
        return f"Circle with radius {self.radius}"

class Triangle(Shape):
    def __init__(self, base, height, side1, side2, side3):
        self.base = base
        self.height = height
        self.side1 = side1
        self.side2 = side2
        self.side3 = side3

    def area(self):
        return 0.5 * self.base * self.height

    def length(self):
        return self.side1 + self.side2 + self.side3

    def volume(self):
        return 0

    def toString(self):
        return f"Triangle with base {self.base}, height {self.height}, and sides {self.side1}, {self.side2}, {self.side3}"

class Cylinder(Shape):
    def __init__(self, radius, height):
        self.radius = radius
        self.height = height

    def area(self):
        return 2 * math.pi * self.radius * self.height + 2 * math.pi * self.radius ** 2

    def length(self):
        return 2 * math.pi * self.radius + 2 * self.height

    def volume(self):
        return math.pi * self.radius ** 2 * self.height

    def toString(self):
        return f"Cylinder with radius {self.radius} and height {self.height}"

# Testing the classes
circle = Circle(5)
triangle = Triangle(10, 8, 6, 7, 8)
cylinder = Cylinder(3, 5)

print(circle.toString())
print(f"Area: {circle.area()}, Length: {circle.length()}, Volume: {circle.volume()}")

print(triangle.toString())
print(f"Area: {triangle.area()}, Length: {triangle.length()}, Volume: {triangle.volume()}")

print(cylinder.toString())
print(f"Area: {cylinder.area()}, Length: {cylinder.length()}, Volume: {cylinder.volume()}")

输出结果：

Circle with radius 5
Area: 78.53981633974483, Length: 31.41592653589793, Volume: 523.5987755982989
Triangle with base 10, height 8, and sides 6, 7, 8
Area: 40.0, Length: 21, Volume: 0
Cylinder with radius 3 and height 5
Area: 150.79644737231007, Length: 37.69911184307752, Volume: 141.3716694115407