class People:
? ?country_or_region='China'
? ?def __init__(self, name):
? ? ? ?self.name = name
? ?def tell(self):
? ? ? ?print('%s is name' %self.name)
obj = People('ak')

# hasattr()
# getattr()
# setattr()
# delattr()
# print('country' in People.__dict__)
# print(hasattr(People, "country_or_region"))
# print(hasattr(People, "name"))
# print(hasattr(People, "tell"))
# print(hasattr(obj, "country_or_region"))
# print(hasattr(obj, "name"))
# print(hasattr(obj, "tell"))
# print(getattr(obj,'country_or_region'))
# print(getattr(obj,'name'))
# print(getattr(obj,'tell',None))
# f = getattr(obj,'tell',None)
# obj.tell()
# f()
# People.date ?= '2023'
# print(People.date)
# setattr(People,'date','2023')
# obj1 = People('ak')
# print(obj1.date)
# print(People.date)
# obj.age = 20
# print(obj.age)
# obj1 = People('kk')
# setattr(obj1,'age',21)
# print(obj1.age)
# print(obj1.__dict__)
# del People.country_or_region
# print(People.__dict__)
# delattr(People,'country_or_region')
# print(People.__dict__)
# del obj.name
# print(obj.__dict__)
# delattr(obj,'name')
# print(obj.__dict__)