Learning notes for classes in Python (source version)

1.1 First paragraph code

#定义一个类(define a class )class Cat:        #属性(attribution)        #方法(methods)        def eat(self):                print("cat is eating a fish.")        def drink(slef):                print("cat is drinking milk.")        def introduce(self):                print("%s‘s age is %d"%(tom.chinese_name,tom.age))#创建一个对象(creating an object)tom = Cat()#调用一个对象的方法(method to invoke an object）tom.eat()tom.drink()#蠢办法添加属性(stupid method to add attributions)tom.chinese_name = "汤姆"tom.age = 18#获取对象的属性(the first way to get  properties of objects )tom.introduce()#创建多个对象，这里创建第二个对象blue_cat(create multiple objects,and the second creates bule cat)blue_cat = Cat()blue_cat.chinese_name = "蓝猫"blue_cat.age = 8blue_cat.introduce()

1.2 Executing the output of the first piece of code

[[email protected] class]# python test.py cat is eating a fish.cat is drinking milk.汤姆‘s age is 18汤姆‘s age is 18    ‘‘‘那这里我们可以看到两个不同的对象调用方法后输出了相同的结果，这就出现问题了，那怎么解决上面的问题，且看下面的代码。‘‘‘

2.1 2nd Way
Self's addition solves the problem above.

#定义一个类(define a class )class Cat:        #属性(attribution)        #方法(methods)        def eat(self):                print("cat is eating a fish.")        def drink(slef):                print("cat is drinking milk.")        def introduce(self):                print("%s‘s age is %d."%(self.chinese_name,self.age))#创建一个对象(creating an object)tom = Cat()#调用一个对象的方法(method to invoke an object）tom.eat()tom.drink()#蠢办法添加属性(stupid method to add attributions)tom.chinese_name = "汤姆"tom.age = 18#获取对象的属性(the first way to get  properties of objects )tom.introduce()#创建多个对象，这里创建第二个对象blue_cat(create multiple objects,and the second creates bule cat)blue_cat = Cat()blue_cat.chinese_name = "蓝猫"blue_cat.age = 8blue_cat.introduce()

2.2 Output of the second segment of the Code

[[email protected] class]# python test.py cat is eating a fish.cat is drinking milk.汤姆‘s age is 18.蓝猫‘s age is 8.

3 Use of init and STR

class Cat:        """定义了一个Cat类"""        #初始化对象        def __init__(self, new_name, new_age):                self.name = new_name                self.age = new_age        def __str__(self):            return "%s的年龄是：%d"%(self.name,self.age)        #方法        def eat(self):                print("猫在吃鱼....")        def drink(self):                print("猫正在喝牛奶.....")        def introduce(self):                print("%s的年龄是:%d"%(self.name, self.age))#创建一个对象tom = Cat("汤姆", 40)bule_cat = Cat("蓝猫", 10)print(tom)print(bule_cat)[[email protected] class]# python test2.py 汤姆的年龄是：40蓝猫的年龄是：10

Learning notes for classes in Python (source version)