python hasattr,getattr,setattr,delattr

#通过字符串操作属性值
class A():
    x=10

obj=A()
#hasattr()
print(dir(obj))
print(hasattr(obj,'x'))
print(hasattr(obj,'y'))

# getattr()
print(getattr(obj,'x'))

# setattr()
setattr(obj,'x','XXX')  #将x修改为'XXX'
print(obj.x)
print(obj.__dict__)

# delattr()
print(obj.__dict__)
delattr(obj,'x')    #删除了自己的x,依旧访问到类中的x
print(obj.x)
# delattr(A,'x')
print(obj.x)    #将类中的x也删除,报错,找不到x

#栗子
class Ftp():
    def put(self):
        print('上传功能')

    def get(self):
        print('下载功能')

    def interactive(self):
        method=input('>>> ').strip()
        if hasattr(self,method):
            getattr(self,method)()
        else:
            print('不存在该功能')

obj=Ftp()
obj.interactive()