# class Foo:#     pass## class Bar(Foo):#     pass### obj=Bar()## # print(isinstance(obj,Bar))# # print(isinstance([],list))## print(issubclass(Bar,Foo))# 反射:指的是通过字符串来操作属性class Foo:    def __init__(self,name):        self.name=nameobj=Foo('egon')# hasattr()# print(hasattr(obj,'name')) #'name' in obj.__dict__# getattr()# print(getattr(obj,'name')) #obj.__dict__['name']# print(getattr(obj,'age')) #obj.__dict__['age']# print(getattr(obj,'age',None)) #obj.__dict__['age']# setattr()# setattr(obj,'age',18) #obj.age=18# setattr(obj,'name','EGON') #obj.name='EGON'# print(obj.__dict__)# delattr()# delattr(obj,'name')# del obj.name# print(obj.__dict__)class Ftp:    def get(self):        print('get')    def put(self):        print('put')    def login(self):        print('login')    def run(self):        while True:            choice=input('>>>: ').strip()            if hasattr(self,choice):                method=getattr(self,choice)                method()            else:                print('命令不存在')obj=Ftp()obj.run()