1. 定义一个矩形类，拥有属性：长、宽 拥有方法：求周长、求面积

class Rectangle:
    def __init__(self, long=10, wide=10):
        self.long1 = long
        self.wide1 = wide

    def area(self):
        print(f'面积：{self.long1*self.wide1}')

    def perimeter(self):
        print(f'周长：{(self.long1+self.wide1*2)}')

1. 定义一个二维点类，拥有属性：x坐标、y坐标 拥有方法：求当前点到另外一个点的距离

class NMR:
    def __init__(self, x1=0, y1=0):
        self.x = x1
        self.y = y1

    def distance(self, x2=0, y2=0):
        print(f'两点间的距离为：{((self.x - x2) ** 2 + (self.y - y2) ** 2) ** 0.5}')

1. 定义一个圆类，拥有属性：半径、圆心 拥有方法：求圆的周长和面积、判断当前圆和另一个圆是否外切

class Circle:
    def __init__(self, radius1=0, center1=(0, 0)):
        self.radius = radius1
        self.center = center1
        # self.radius0 = radius2
        # self.center0 = center2

    def perimeter(self, a=3.14):
        print(f'圆的周长是：{2*a*self.radius}')

    def area(self, a=3.14):
        s = f'圆的面积为：{a * self.radius ** 2}'
        return s

    def combination(self, radius0=0, center0=(0, 0)):
        if self.radius + radius0 == ((self.center[0] - center0[0])**2 + (self.center[1] - center0[1])**2)**0.5:
            print('外切')
        else:
            print('没有外切')

1. 定义一个线段类，拥有属性：起点和终点， 拥有方法：获取线段的长度

class Line:
    def __init__(self, start1=(0, 0), end1=(0, 0)):
    	pass

1. 定义一个狗类和一个人类：

   狗拥有属性：姓名、性别和品种 拥有方法：叫唤

   人类拥有属性：姓名、年龄、狗 拥有方法：遛狗

   class Dog:
       def __init__(self, name1='', sex1='', var1=''):
           self.name = name1
           self.sex = sex1
           self.var = var1
   
       def action(self):
           print(f'{a}叫唤')
   
   
   a = Dog('大黄').name
   Dog().action()
   
   
   class Person:
       def __init__(self, name2='', age='', dog=a):
           self.name = name2
           self.age = age
           self.dog = dog
   
       def action(self):
           print(f'{self.name}遛{self.dog}')