Question

我有一个简单的程序：

class Coordinate(object):
    def __init__(self, x , y):
        self.x = x
        self.y = y
    def distance (self, other):
        x_diff = (self.x-other.x)**2
        y_diff = (self.y - other.y)**2
        return (x_diff+y_diff)**0.5
    def __str__(self):
        return "<" + str(self.x) + "," + str(self.y) + ">"
    def __sub__(self,other):
        return Coordinate(self.x - other.x,self.y - other.y)


c = Coordinate (3,4)
o = Coordinate (1,1)

c - o给了我<2,3>。

现在，如果我将__sub__()更改为：

    def __sub__(self,other):
        return self.x - other.x

并运行程序：

c - o仍然给我<2,3>而不是2。

Answer 1

为我工作。

class Coordinate(object):
    def __init__(self, x , y):
        self.x = x
        self.y = y
    def distance (self, other):
        x_diff = (self.x-other.x)**2
        y_diff = (self.y - other.y)**2
        return (x_diff+y_diff)**0.5
    def __str__(self):
        return "<" + str(self.x) + "," + str(self.y) + ">"
    def __sub__(self,other):
        return self.x- other.x

c= Coordinate (3,4)
o = Coordinate (1,1)
c - o

输出

Answer 2

如您所见，它返回2。您可能做错了什么。看图片 code running

为什么我的操作不会改变价值？ [类]

2 个答案: