PY__11 类和对象 继承

python

类和对象

class exployee:
    exployee_count=0  #查看人数
    def __init__(self,name,salary):
        self.name=name
        self.salary=salary
        exployee.exployee_count+=1  #查看人数
    def display(self):
        print('my name is{0} and my salary is{1}'.format(self.name,self.salary))
===========================================================
ex1=exployee('admin',2000)  #构造方法
print(ex1.name,ex1.salary) #admin 2000  #不能遍历对象的属性

ex1.display()  #my name isadmin and my salary is2000

print(exployee.exployee_count) #1 共一个人
====================================================
del ex1.name  #删除ex1的name属性
print(ex1.name) #'exployee' object has no attribute 'name'
ex1=None  #手动回收
=====================================================
setattr(ex1,'salary',200)  #  添加属性
ex1.display()

hasatter(对象名，属性名）判断一个对象是否有这个属性

if hasattr(ex1,'salary'): #判断ex1是否有salary属性
    del ex1.salary
            #简写 hasatter(ex1,'salary'） and  del ex1.salary
ex1.display()

isinstance(对象名，类名）判断一个对象是否属于这个类

class Exployee:
    def __init__(self, name, salary):
        self.name = name
        self.salary = salary

def  setSalary(obj):
    if isinstance(obj,Exployee): #若是属于Exployee类则发工资
        print('pay:{0}'.format(obj.salary))

ex1=Exployee('tom',2000)

setSalary(ex1)    #True
                    pay:2000
user={}
setSalary(user)  #False 不属于Exployee类所以不发工资

继承

class Exployee(object):
    def __init__(self,name,salary):
        self.name=name
        self.salary=salary
    def display(self):
         print('my name is{0},and salary is{1}'.format(self.name, self.salary))

继承类的属性和行为

class Manager(Expoyee): #Manager类继承Exployee类的属性和行为
    def __init__(self,name,salary,bonus): # 写出Manager的所有属性
        super(Manager,self).__init__(name,salary) #写出Manager继承的属性
        self.bonus=bonus   # 写出Manager新增的属性


    def display(self): 重写 （重写父类的display方法，覆盖override）
        print('my name is{0},and salary is{1},bonus is{2}'.format(self.name,self.salary,self.bonus))

    #下面的写法更正规
    def display(self):
        super(Manager,self).display()
        print('and bonus is{0}'.format(self.bonus))

ex1=Manager('tom',2000,3000) #为Manager类创建对象，比原来的Exployee多了bouns
ex1.display()  #my name istom,and salary is2000,bonus is3000

print(isinstance(ex1,Exployee))#True
print(isinstance(ex1,Manager))#True  e1既属于Exployee类又属于Manager类

args可以为Manager添加不定数属性

class Manager(Exployee):
    def __init__(self,name,salary,bonus,*args):
        super(Manager,self).__init__(name,salary)
        self.bonus=bonus
        if args: # 若存则添加
            self.args=args
m1=Manager('joke',2000,300,12,13)
print(m1.args)

多继承和多态

多态，没有继承就没有多态

不同对象调用同一个方法出现不同结果

class Exployee(object):
    def __init__(self,name,salary):
        self.name=name
        self.salary=salary

    def display(self):
         print('my name is{0},and salary is{1}'.format(self.name, self.salary))

class Room():
    def __init__(self,room_id):
        self.room_id=room_id

class Manager(Exployee,Room):
    def __init__(self,name,salary,bonus,room_id):
        super(Manager,self).__init__(name,salary)
                                                #Exployee.__init__(self, name, salary)
        Room.__init__(self,room_id)
        self.bonus=bonus

    def display(self):
        print('my name is{0},and salay is{1},and bonus is{2}'.format(self.name,self.salary,self.bonus))
m1=Manager('admin',2000,300,'308')
print(m1.room_id)

e1=Exployee('Tom',2000)

多态，没有继承就没有多态
不同对象调用同一个方法出现不同结果
e1.display()  #my name isTom,and salary is2000
m1.display()  #my name isadmin,and salay is2000,and bonus is300

动态绑定方法

from  types import MethodType
class Exployee(object): #任何类都是object类的子类

    def __init__(self,name,salary):
        self.name=name  #对象属性，实例属性
        self.salary=salary

def display(self):
         print('my name is{0},and salary is{1}'.format(self.name, self.salary))

ex01=Exployee('tom',200)
ex01.gener='male' #动态绑定属性
print(ex01.gener)

ex01.dis=MethodType(display,ex01) #动态添加行为
ex01.dis()
ex01.display=MethodType(display,ex01) #动态添加行为
ex01.display()  一般和后面的方法名写一样的名字

del ex01.dis  #动态删除行为
ex01.dis()