写了这么多行就给我30，呜呜呜

class ShortInputError(Exception):
    def __init__(self):
        pass
    def __str__(self):
        return f'向量的长度不对'
class Vector:
    # 构造方法，初始化，定义向量，需要把参数的各元素转化为浮点数
    def __init__(self, data):
        self.__data=data
        if isinstance(self.__data,tuple) or isinstance(self.__data,list):
            pass
        else:
            print('输出格式有误')
    def get(self):
        return self.__data,len(self.__data)
        # 与两一个向量相加，对应分量相加，返回新向量

    def __add__(self, anotherPoint):
        try:
            if len(self.__data)!=anotherPoint.get()[1]:
                raise ShortInputError()
        except Exception as result:
            print(result)
        else:
            print('是两个合法的向量')
        finally:
            ret = [self.get()[0][i]+anotherPoint.get()[0][i] for i in range(anotherPoint.get()[1])]
            return ret

        # 减去另一个向量，对应分量相减，返回新向量

    def __sub__(self, anotherPoint):
        try:
            if len(self.__data)!=anotherPoint.get()[1]:
                raise ShortInputError()
        except Exception as result:
            print(result)
        else:
            print('是两个合法的向量')
        finally:
            ret = [self.get()[0][i]-anotherPoint.get()[0][i] for i in range(anotherPoint.get()[1])]
            return ret
        # 向量与一个数字相乘，各分量乘以同一个数字，返回新向量

    def __mul__(self, n):
        ret=[i*n for i in self.__data]
        return ret
    # 向量除以一个数字，各分量除以同一个数字，返回新向量
    def __truediv__(self, n):
        if n==0:
            print('错误')
            return
        else:
            ret = [i / n for i in self.__data]
            return ret

    def __getitem__(self, index):
        if index>len(self.__data)-1 or index<-len(self.__data):
            print('错误')
            return
        else:
            return self.__data[index]

    def __setitem__(self, index, v):
        if index>len(self.__data)-1 or index<-len(self.__data):
            print('错误')
            return
        else:
            self.__data[index]=v
            return self.__data
        # 查看向量长度，所有分量平方和的平方根

    @property
    def length(self):
        ret = [i **2 for i in self.__data]
        return sum(ret)**0.5

    def __str__(self):
        return ('这是一个实例化对象')
li=[1,2,3]
li1=[4,5,6]
li2=[3,4,5]
a=Vector(li)
b=Vector(li1)
c=Vector(li2)
ret=a.__getitem__(1)
print(ret)
ret=a.__add__(b)
print(ret)
ret=a.__sub__(b)
print(ret)
ret=a.__truediv__(0)
print(ret)
ret=a.__truediv__(0.5)
print(ret)
ret=a.__setitem__(1,4)
print(ret)
ret=c.length
print(ret)
print(c)