python中反射的三个方法hasattr，getattr，setattr

hasattr(obj,attr) getattr(obj,attr) setattr(obj,attr,val)

class People:
    def eat(self):
        print('eat')
    def drink(self):
        print('drink')
    def code(self):
        print('code')
p = People()   # p为指向类的实例

hasattr(p,'eat')  # 在实例中是否有eat方法  

True

hasattr(p,'code') 

True

getattr(p,'code')  # 在实例中取code方法

<bound method People.code of <__main__.People object at 0x000001A5E387E4E0>>

code123 = getattr(p,'code')

code123()      # 调用类的的方法

code

setattr(p,'sleep','sleep1234')  # 在实例中设置sleep属性值为"sleep1234"

p.sleep            # 调用实例内sleep方法

'sleep1234'