class Student: def __init__(self,name,age): self.name=name self.__age=age #年龄不希望在类的外部被使用,所以加了两个“_” def show(self): print(self.name,self.__age) stu=Student('张三',20) stu.show() #张三 20 #在类的外部使用name与age print(stu.name) print(stu._Student__age) #在类的外部可以通过_Student__age进行访问,20
class Person(object):#Person继承object类 def __init__(self,name,age): self.name=name self.age=age def info(self): print(self.name,self.age) #定义子类 class Student(Person): def __init__(self,name,age,stu_no): super().__init__(name,age) self.stu_no=stu_no class Teacher(Person): def __init__(self,name,age,teachofyear): super().__init__(name,age) self.teachofyear=teachofyear stu=Student('张三',20,'1001') teacher=Teacher('李四',34,10) stu.info() teacher.info()
class Person(object): def __init__(self,name,age): self.name=name self.age=age def info(self): print(self.name,self.age) class Student(Person): def __init__(self,name,age,stu_no): super().__init__(name,age) self.stu_no=stu_no def info(self): #重写 super().info() print(self.stu_no) class Teacher(Person): def __init__(self,name,age,teachofyear) super().__init__(name,age) self.teachofyear=teachofyear def info(self):#重写 super().info() print(self.teachofyear) stu=Student('张三',20,'1001') teacher=Teacher('李四',34,10) stu.info() teacher.info()
3. object类
class Student: def __init__(self,name,age): self.name=name self.age=age def __str__(self): return '我的名字是{0},今年{1}岁'.format(self.name,self.age) stu=Student('张三',20) print(stu)
class Animal(object): def eat(self): print('动物会吃') class Dog(Animal): def eat(self): print('狗吃骨头') class Cat(Animal): def eat(self): print('猫吃鱼') class Person: def eat(self): print('人吃五谷杂粮') #定义一个函数 def fun(obj): obj.eat() #开始调用函数 fun(Cat()) fun(Dog()) fun(Animal()) fun(Person())
#print(dic(object)) class A: pass class B: pass class C(A,B): def __init__(self,name,age): self.name=name self.age=age #创建C类的对象 x=C('Jack',20)#x是C类型的一个实例对象 print(x.__dict__)#实例对象的属性字典 print(C.__dict__) print(x.__class__) #输出了对象所属的类 print(C.__bases__) #C类的父亲类型的元素 print(C.__base__) #类的基类,按顺序第一,因为C(A,B),所以是A print(C.__mro__) #类的层次结构 print(A.__subclasses__())#子类的列表
a=20 b=100 c=a+b#两个整数类型的对象的相加操作 d=a.__add__(b) print(c) print(d) class Student: def __init__(self,name): self.name=name def __add__(self,other): return self.name+other.name def __len__(self): return len(self.name) stu1=Student('张三') stu2=Student('李四') s=stu1+stu2 print(s) #张三李四 s=stu1.__add__(stu2) print(s) #张三李四 lst=[11,22,33,44] print(len(lst))#len是内容函数len,4 print(lst.__len__())#4 print(len(stu1))#2
class Person(object): def __new__(cls,*args,*kwargs): print('__new__被调用执行了,cls的id值为{0}',format(id(cls))) obj=super().__new__(cls) print('创建的对象的id为:{0}',format(id(obj))) return obj def __init__(self,name,age): print('__init__被调用了,self的id值为:{0}',format(id(self))) self.name=name self.age=age print('object这个类对象的id为:{0}',format(id(object))) print('Person这个类对象的id为:{0}',format(id(Person))) #创建Person类的实例对象 p1=Person('张三',20) print('p1这个Person类的实例对象的id:{0}',format(id(p1)))