AttributeError: 'Vector' object has no attribute 'plus' while adding new method in class Vector using python 2.7

Question

我正在尝试向 python 2.7 中的 class Vector 添加新方法，而运行程序，它 return 错误消息 python class 中创建的方法没有属性。源代码如下：

class Vector(object):
     def __init__(self, coordinates):
          try:
              if not coordinates:
                   raise ValueError
              self.coordinates = tuple(coordinates)
              self.dimension = len(coordinates)
          except ValueError:
              raise ValueError('The coordinates must be nonempty')
          except TypeError:
              raise TypeError('The coordinates must be an iterable')
     def __str__(self):
          return 'Vector: {}'.format(self.coordinates)
     def __eq__(self, v):
          return self.coordinates == v.coordinates
     def plus(self, v):
          new_coordinates = [x+y for x, y in zip(self.coordinates, v.coordinates)]
          return Vector(new_coordinates)

myVector1 = Vector([8.218, -9.341])
myVector2 = Vector([-1.129, 2.111])
print myVector1.plus(myVector2)
output error message:
AttributeError: 'Vector' object has no attribute 'plus'

Answer 1

您没有正确限定函数的范围，方法必须在 class:

中

class Vector(object):
    def __init__(self, coordinates):
        try:
            if not coordinates:
                raise ValueError
            self.coordinates = tuple(coordinates)
            self.dimension = len(coordinates)

        except ValueError:
            raise ValueError('The coordinates must be nonempty')

        except TypeError:
            raise TypeError('The coordinates must be an iterable')

    def __str__(self):
        return 'Vector: {}'.format(self.coordinates)

    def __eq__(self, v):
        return self.coordinates == v.coordinates

    def plus(self, v):
            new_coordinates = [x + y for x,y in zip(self.coordinates, v.coordinates)]
            return Vector(new_coordinates)

AttributeError: 'Vector' object has no attribute 'plus' while adding new method in class Vector using python 2.7

AttributeError: 'Vector' object has no attribute 'plus' while adding new method in class Vector using python 2.7

python

vector

algebra