class Test:def __init__(self,name):self.name=namedef __enter__(self):print('this is enter')return self#返回一个值给fdef __exit__(self, exc_type, exc_val, exc_tb):print('this is exit')print(exc_type,'exctype')#在代码块内如果有一场的话，会将异常类型，异常值，追踪信息返回print(exc_val,'val')print(exc_tb,'tb')
with Test('a') as f:#此时出发enterprint('start opening')#在with内执行代码
print('this is end')#with内代码执行完，执行exit代码，接着执行本段代码

class Fun:def __init__(self,name,age,gender):#name为字符串，age为数字，gender为字符串self.name=nameself.age=ageself.gender=genderdef show(self):print(self.name,self.age,self.gender)
p1=Fun('100','yehaibin','male')
p1.show()#并不能对输入的类型进行限制
#其他解决方法：直接str或者int

#利用描述符以及描述符的优先级，来给用户输入的值进行类型检测#传入的值必须是字符串，否则报错
#实例化的时候，如果错了，在调用时提醒
#对值进行设置的时候，如果错了，则提醒，get和set
class Name_Str:def __init__(self,key):self.key=keydef __get__(self, instance, owner):#instance是传来的实例，# print(instance)return instance.__dict__[self.key]def __set__(self, instance, value):if isinstance(value,str):# type(self.key) == str:instance.__dict__[self.key] = valueelse:print('your input %s is wrong,please input an str' %self.key)def __delete__(self, instance):pass
class Age_Int:def __init__(self,key):#key为‘’ageself.key=keydef __get__(self, instance, owner):#instance是传来的实例，# print(instance)return instance.__dict__[self.key]def __set__(self, instance, value):if isinstance(value,int):# type(self.key) == str:instance.__dict__[self.key] = valueelse:print('your input %s is wrong,please input an int' %self.key)def __delete__(self, instance):passclass Fun:#直接在设置属性的时候，进行查看name=Name_Str('name')age=Age_Int('age')gender=Name_Str('gender')def __init__(self,name,age,gender):#name为字符串，age为数字，gender为字符串self.name=nameself.age=ageself.gender=genderdef show(self):print(self.name,self.age,self.gender)
p1=Fun('100',555,'100')
# print(p1.name)#因为数据描述符的属性比实例属性的级别高，所以直接调用数据描述符get
# p1.name='500'
# print(p1.name)
# p1.gender='500'
# print(p1.gender)
p1.age=11#出发set，p1为instance，11为value
print(p1.age)