# -*- coding: utf-8 -*-

 """

 Created on Mon Nov 12 15:05:20 2018

 @author: zhen

 """

 class Aricraft:

     mileages = 0.0 # 类变量，在该类及其子类的实例*享

     def __init__(self, engine, speed):

         self.engine = engine

         self.speed = speed

     def fly(self, miles):

         Aricraft.mileages += miles

         print("the aircrift has", Aricraft.mileages, "miles")

 aricraft = Aricraft("涡扇9", "800km/h")

 aricraft.fly(1000)

 aricraft.fly(600)

 class Fighter(Aricraft): # 继承

     def __missile(self): # 私有方法，只能类内访问

         print("emission missile !")

     def fly(self, miles):

         Aricraft.mileages += miles

         print("the fighter has", Aricraft.mileages, "miles")

         Fighter.__missile(self)

 fighter = Fighter("涡扇15", "1200km/h")

 fighter.fly(1800)

 fighter.fly(1600)

 # fighter.__missile()  AttributeError: 'Fighter' object has no attribute '__missile'