Question

下面的代码由于某种原因给我一个错误，有人可以告诉我会出现什么问题..

基本上，我创建了2个类Point＆amp; Circle.THe圈试图继承Point类。

Code:


class Point():

    x = 0.0
    y = 0.0

    def __init__(self, x, y):
        self.x = x
        self.y = y
        print("Point constructor")

    def ToString(self):
        return "{X:" + str(self.x) + ",Y:" + str(self.y) + "}"

class Circle(Point):
    radius = 0.0

    def __init__(self, x, y, radius):
        super(Point,self).__init__(x,y)
        self.radius = radius
        print("Circle constructor")

    def ToString(self):
        return super().ToString() + \
               ",{RADIUS=" + str(self.radius) + "}"


if __name__=='__main__':
        newpoint = Point(10,20)
        newcircle = Circle(10,20,0)

错误：

C:\Python27>python Point.py
Point constructor
Traceback (most recent call last):
  File "Point.py", line 29, in <module>
    newcircle = Circle(10,20,0)
  File "Point.py", line 18, in __init__
    super().__init__(x,y)
TypeError: super() takes at least 1 argument (0 given)

Answer 1

看起来您已经修复了原始错误，这是由错误消息指示的super().__init__(x,y)造成的，虽然您的修补程序稍有不正确，而不是来自super(Point, self)的{{1}}你应该使用Circle。

请注意，还有另一个地方在super(Circle, self)的{{1}}方法内错误地调用了super()：

Circle

这是Python 3上的有效代码，但在Python 2上ToString()需要参数，请将其重写如下：

        return super().ToString() + \
               ",{RADIUS=" + str(self.radius) + "}"

我还建议删除续行，请参阅Maximum Line Length section of PEP 8以了解修复此问题的方法。

Answer 2

super(..)只接受新式课程。要修复它，请从object扩展Point类。像这样：

class Point(object):

使用super（..）的正确方法也是：

super(Circle,self).__init__(x,y)

Answer 3

class Point(object):

x = 0.0
y = 0.0

def __init__(self, x, y):
    self.x = x
    self.y = y
    print("Point constructor")

def ToString(self):
    return "{X:" + str(self.x) + ",Y:" + str(self.y) + "}"

class Circle(Point,object):
radius = 0.0

def __init__(self, x, y, radius):
    super(Circle,self).__init__(x,y)
    self.radius = radius
    print("Circle constructor")

def ToString(self):
    return super(Circle, self).ToString() + \
           ",{RADIUS=" + str(self.radius) + "}"


if __name__=='__main__':     
    newpoint = Point(10,20)    
    newcircle = Circle(10,20,0)

Python类 - 超级变量

3 个答案: