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

class Dog:
    """一个狗的类"""

    def __init__(self, name, variety, gender='公'):
        self.name = name
        self.gender = gender
        self.variety = variety

    def __repr__(self):
        return str(self.__dict__)

    def cry_dog(self):
        """叫唤名字，狗就会旺旺旺"""
        return f"{self.name},我旺不旺\n旺旺旺"


dog = Dog('旺财', '中华田园犬')
print(dog)

print(dog.cry_dog())

人类拥有属性：姓名、年龄、狗 拥有方法：遛狗

class Person:
    """人的类"""
    def __init__(self, name, age):
        self.name = name
        self.age = age
        self.dog1 = dog

    def __repr__(self):
        return str(self.__dict__)

    def walk_the_dog(self):
        """遛狗"""
        return f'{dog.name} 速度过来'


person = Person('睿睿', '28')
print(person)
print(person.walk_the_dog())

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:
    """一个矩形类"""
    def __init__(self, long, wide):
        self.long = long
        self.wide = wide

    def perimeter(self):
        """求周长"""
        return f'周长为：{(self.wide + self.long) * 2}'

    def area(self):
        """求面积"""
        return f'面积为：{self.long * self.wide}'


rectangle = Rectangle(10, 10)
print(rectangle.perimeter())
print(rectangle.area())

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 Coordinates:
    """定义一个二维点类"""
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def distance(self):
        """求x到y的距离"""
        return f'求x到y的距离为：{(self.x ** 2 + self.y ** 2) ** 0.5:.2f}'


coordinates = Coordinates(-1234, 5678)
print(coordinates.distance())

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:
    """一个圆类"""
    pi = 3.141592653

    def __init__(self, r, x_label):
        self.r = r
        self.x_label = x_label

    def area(self):
        """ 计算圆面积"""
        return '半径为：{self.r}时，面积：{P.pi * self.r ** 2 :.2f}'

    def perimeter(self):
        """ 计算圆周长"""
        return '半径为：{self.r}时，周长：{2 * P.pi * self.r:.2f}'

    def exterior_contact(self, r1, x1, y1):
        """判断当前圆和另一个圆是否外切"""
        if ((self.x_label[0] - x1) ** 2 + (self.x_label[-1] - y1) ** 2) ** 0.5 == self.r + r1:
            return '是外切'
        else:
            return '非外切'


c1 = Circle(61, [1, 1])
print(c1.exterior_contact(60, 1, 122))

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 LineSegment:
    """一个线段类"""
    def __init__(self, origin, destination):
        self.origin = origin
        self.destination = destination

    def length(self):
        return self.destination - self.origin


lineSegment = LineSegment(2345, 4567890)
print(lineSegment.length())