python 第3天

2020-01-03 13:32:47 浏览数 (1)

class Hotdog:

def __init__(self):  #初始化对象

        self.cooked_level = 0

        self.cooked_string ="Raw"

        self.condiments = [] #空数组

def __str__(self):  #print(对象)

        msg = "hot dog"

        if len (self.condiments) > 0 :

            msg = msg " with"

        for i in self.condiments:

            msg = msg " " i ","

        msg = msg.strip(",")

        msg = self.cooked_string " " msg "." str(self.cooked_level)

        return msg

    def cook (self,time):

        self.cooked_level = self.cooked_level time

        if self.cooked_level > 8:

            self.cooked_string = "Charcoal"

        elif self.cooked_level > 5:

            self.cooked_string = "Well_down"

        elif self.cooked_level >=3:

            self.cooked_string = "Medium"

        else:

            self.cooked_string = "Raw"

    def addCondiment(self,condiments):

        self.condiments.append(condiments)

myDog = Hotdog()

print (myDog)

print ("Cooking hot dog for 4 minutes...")

myDog.cook(4)

print (myDog)

print ("Cooking hot dog for 3 minutes...")

myDog.cook(3)

print (myDog)

print ("Cooking hot dog for 10 minutes...")

myDog.cook(10)

myDog.cooked_level=3 # 这些对象的属性都可以更改,不用通过方法,python 没有提供隐藏数据的方法,不过可以自己搞定。

print (myDog)

print ("Now I'm going to add some stuff on my hot dog")

myDog.addCondiment("ketchup")

myDog.addCondiment("mustard")

print (myDog)

设置私有变量和私有方法可以用__开头

class Person:

    def __init__(self):

        self.__name = "jixiang"

        self.age = 22

    def __get_name(self):

        return self.__name

    def get_name(self):

        return self.__name

    def get_age(self):

        return self.age

    def change_name(self):

        self.__name = "malong"

        return self.__name

    def change_name1(self):

self.__name = "jilong" #可以清楚的看到无论是私有属性还是私有方法在类内都可以使用。

        newname=self.__get_name()

        return newname

person = Person()

print (person.get_age())

#print (person.__get_name())  #无论是私有变量还是私有方法都无法访问。

#print (person.__name)

person.__name ="lilong" #这里虽然没有报错,但是你看下面,打印出来依然没有改变

print (person.get_name())

person.change_name()

print (person.get_name())

person.change_name1()

print (person.get_name())

下面进入多态 ,

封装继承多态是面向对象的重要内容。

多态

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