综合之前的类的学习，做以下实例练习：（建议先不要看代码，自己先试着写；代码仅供参考，有多种实现方法）
1.Triangle & Equilateral
1). 创建class Triangle 表示三角形，包含三个属性值：angle1、angle2、angle3；
类方法 check_angles()：若三个角相加 == 180，return True；若不是，return False
1classTriangle(object):2def__init__(self,angle1,angle2,angle3):3self.angle1 =angle14self.angle2 =angle25self.angle3 =angle367defcheckAngles(self):8if(self.angle1+self.angle2+self.angle3) == 180:9returnTrue10else:11returnFalse1213t1 = Triangle(40,50,90)14PRint(t1.angle1,t1.angle2,t1.angle3)15print(t1.checkAngles())16t2 = Triangle(40,50,91)17print(t2.checkAngles())
Triangle
2). 创建class Equilateral 继承上例1的Triangle，表示等边三角形，同Triangle不同点在于，其属性值的三个角均为60；而对应的check_angles()自然始终返回True
1classEquilateral(Triangle):2def__init__(self,angle1=60,angle2=60,angle3=60):3self.angle1 =angle14self.angle2 =angle25self.angle3 =angle367t3 =Equilateral()8print(t3.angle1,t3.angle2,t3.angle3)9print(t3.checkAngles())
Equilateral 1
如上示例代码可满足条件，但更好的做法是调用父类构造函数，并重写check_angles()使其始终返回 True，参见代码如下
1classEquilateral(Triangle):2def__init__(self,angle1=60,angle2=60,angle3=60):3Triangle.__init__(self,angle1,angle2,angle3)45defcheckAngles(self):6returnTrue78t3 =Equilateral()9print(t3.angle1,t3.angle2,t3.angle3)10print(t3.checkAngles())
Equilateral 2
2. Car & ElectricCar
1).创建class Car 成员变量condition = "new"，包含三个构造属性：model,color,mpg；
类方法 displayCar() print 拼接的字符串 This is a {color} {model} car with {mpg} MPG. 如 "This is a blue Xmodel car with 40 MPG."
类方法 driveCar() 改变成员变量condition = "used"
1classCar(object):2condition ="new"3def__init__(self,model,color,mpg):4self.model =model5self.color =color6self.mpg =mpg78defdisplayCar(self):9print("This is a {s.color} {s.model} car with {s.mpg} MPG.".format(s=self))1011defdriveCar(self):12self.condition ="used"1314car1 = Car("DeLorean","silver", 88)15car1.displayCar()16print(Car.condition)17print(car1.condition)18car1.driveCar()19print(car1.condition)
Car
2). 创建class ElectricCar 继承 Car，新增一属性变量 battery_type；重写driveCar()函数，改变 condition = "like new"
1classElectricCar(Car):2def__init__(self,model,color,mpg,battery_type):3Car.__init__(self,model,color,mpg)4self.battery_type =battery_type56defdriveCar(self):7self.condition ="like new"89car2 = ElectricCar("dd","Red",88,"molten salt")10print(car2.battery_type,car2.condition)11car2.displayCar()#继承Car方法12car2.driveCar()#调用重写后的方法13print(car2.condition)
ElectricCar
3. Point3D
创建class Point3D，表示三维坐标上的一个点，包含三个属性变量：x,y,z
类 __repr__ 方法显示为 (x,y,z)
类方法 distance() 返回改点距原点(0,0,0) 的距离
Python 类方法 __repr__ 重写 print class_name 时的显示，参考代码即可理解
1importmath2classPoint3D(object):3def__init__(self,x,y,z):4self.x =x5self.y =y6self.z =z7def__repr__(self):8return("({s.x},{s.y},{s.z})".format(s=self))910defdistance(self):11d = math.sqrt(self.x**2+self.y**2+self.z**2)12returnd1314point1 = Point3D(3,4,0)15print(point1)16print(point1.distance())
Point3D
4. Employee & PartTimeEmployee
1).创建class Employee，包含成员变量hour_wage =20，构造函数包含属性变量：name;
类方法 calculateWage() 计算当天工钱，传参hours，return hours*hour_wage
1classEmployee(object):2hour_wage = 203def__init__(self,name):4self.name =name56defcalculateWage(self,hours):7returnself.hour_wage*hours89Peter = Employee("Peter")10print(Peter.calculateWage(5))
Employee
2). 创建class PartTimeEmployee 继承 Employee，成员变量hour_wage=18, parttime_wage=15 构造函数同Employee
类方法calculateWage()重写，若是hour>=8，则 return hour_wage*hours；若是hour<8,return parttime_wage*hours
1classPartTimeEmployee(Employee):2hour_wage=183parttime_wage=1545defcalculateWage(self,hours):6ifhours>=8:7returnself.hour_wage*hours8else:9returnself.parttime_wage*hours1011May = PartTimeEmployee("May")12print(May.calculateWage(5))13print(May.calculateWage(8))
PartTimeEmployee