python类学习

luyantl

class Dog():
    def __init__(self,name,age):    #前边和后边是两个下划线
        self.name=name
        self.age=age

    def sit(self,name="测试关键字参数"):
        print(self.name.title()+"坐下的行为"+"\t第二参数=>"+name+"\t\t"+self.name+name)

    def roll(self):
        print(str(self.age)+"小狗的年龄")
        
   
myDog=Dog("旺财",3)
myDog.sit()
myDog.roll()
myDog.name="小强"
myDog.sit()

luyantl

class Car():
    def __init__(self,make,model,year):
        self.make=make
        self.model=model
        self.year=year


class Battery():
    def __init__(self,batterySize=70):
        self.batterySize=batterySize

    def describeBattery(self):
        print("尺寸"+str(self.batterySize))

class Electric(Car):
    def __init__(self,make,model,year):
        super().__init__(make,model,year)
        self.battery=Battery()

demo=Electric("德国","奔驰",2018)
demo.battery.describeBattery()

luyantl

from random import randint
class Die():
    def __init__(self,sides=9):
        self.sides=sides

    def rollDie(self,sides=6):
        
        for i in range(0,10):
            x=randint(1,sides)
            print(x)

py=Die()
py.rollDie(6)
print("=========6========")
py.rollDie(10)
print("=========10========")
py.rollDie(20)
print("=========20========")

luyantl

__init__()方法只写成

__init__(self)为什以会报错??????