1、反射

用字符串来操作类或者对象的属性

class People:
#     country= 'china'
#     def __init__(self,name):
#         self.name= name
#
#     def eat(self):
#         print('%s is eating'%(self.name))
# peo1= People ('qqc')

(1)hasattr

print(hasattr(peo1,'name')) #判断name是否在peo1.name中是可以访问的属性

(2)getarrt

print(getattr(peo1,'xx','None'))#在peo1中没有xx这个属性，返回None，不会报错

(3)strattr

setattr(peo1,'age',19)    #增加属性
# print(peo1 .__dict__ )

(4)delattr(peo1,'name')  #删除

2、1.内置方法__str__

class People:
# #     def __init__(self,name,age):
# #         self.name = name
# #         self.age= age
# #     #在对象self被打印时，自动触发 ,应该在方法内采集与对象self有关的信息，然后拼成字符串返回
# #     def __str__(self):
# #         return '姓名%s,年龄%s'%(self.name,self .age)
# #
# # obj = People ('qqc',33)
# # print(obj)

2、2.内置方法__del__

__del__析构方法
# class People:
#      def __init__(self,name,age):
#         self.name = name
#         self.age= age
#         self.f= open('q.txt','rt',encoding= 'utf-8')
#      def __del__(self):
#          #做回收系统资源相关的事情
#          self.f.close()
#          print('ggg')
#
# obj = People('egon',18)
# del obj