python3 使用数据描述器，验证字段类型

class Typed:
 
    def __init__(self,type,name):
        self.type = type
        #name 存储变量
        self.name = name
 
    def __set__(self, instance, value):
        if not isinstance(value,self.type):
            raise ValueError(value)
        instance.__dict__[self.name] = value
 
 
    def __get__(self, instance, owner):
        value = instance.__dict__[self.name]
        return value
 
#类中实现检查(inpsect)
import inspect
class TypeAssert:
 
    def __init__(self,cls):
        self.cls = cls
        params = inspect.signature(self.cls).parameters
        for name, param  in params.items():
            print(name, param.annotation)
            if param.annotation != param.empty:
                setattr(self.cls,name,Typed(param.annotation,name)) #注入类属性
 
                print(Typed.__dict__)
 
 
    def __call__(self, name,chinese,math):
        p = self.cls(name,chinese,math)
        return  p
 
@TypeAssert
class Student:
 
    def __init__(self, name:str,chinese:float, math:float):
        self.name = name
        self.chinese = chinese
        self.math = math
 
    def __repr__(self):
 
        return "student name:{} chinese:{} math:{}".format(self.name,self.chinese,self.math)
 
 
c = Student('tom',66.3, 80.5)
c2 = Student('jack',80.6, 99.5)
 
print(c,c2)<br>打印结果:student name:tom chinese:66.3 math:80.5 student name:jack chinese:80.6 math:99.5