Question

这是我在这里的第一篇文章，所以如果有任何错误，请告诉我。

这是我的代码：

import math
class Square():
    def __init__(self, length):
        self.length = length


    def getL(self,length):
        self.length = length
        print(length)


    def getP(self,length):
        return length * 4

    def getA(self,length):
        return length * length

    def __add__(self,another_square):
        return Square(self.length + another_square.length)

s1 = Square()
s2 = Square()
print(s1.setL(5))
print(s1.getP(5))
print(s1.getA(5))
print(s2.getP(12))
print(s2.getA(15))
s3 = s1 + s2
print(s3.getA())

当我运行它时会给我一个TypeError：

Traceback (most recent call last):
File "C:\Users\user\Desktop\programming.py", line 21, in <module>
s1 = Square()
TypeError: __init__() missing 1 required positional argument:'length'

我想知道我的代码有什么问题，任何帮助都会受到赞赏。

Answer 1

您需要将参数传递给构造函数。

s1 = Square(1) # will call Square.__init__(self, 1)
s2 = Square(2) # will call Square.__init__(self, 2)

这不是一个大问题。

更新

我重写了你的课程：

import math
class Square():
    def __init__(self, length):    #return an instance of this class with 'length' as the default length.
        self.length = length

    def setL(self,length):    #pass length to the instance and override the original length.
        self.length = length

    def getL(self):           #get the length of instance.
        return self.length

    def getP(self):           #get the perimeter of instance.
        return self.length * 4

    def getA(self):           #get the area of instance.
        return self.length ** 2

    def __add__(self,another_square):     #return a new instance of this class with 'self.length + another_square.length' as the default length.
        return Square(self.length + another_square.length)

我认为你在阅读我的代码后可以意识到你真正的问题是什么。并且对上面的代码进行了测试。

s1 = Square(1)
s2 = Square(2)
print(s1.getP())
print(s1.getA())
print(s2.getP())
print(s2.getA())
s3 = s1 + s2
print(s3.getA())

output:
4
1
8
4
9

Answer 2

你的类init需要一个长度参数，你试图创建s1而不给它一个

Answer 3

您正在初始化Square的实例而未指定length参数。

s1 = Square()
s2 = Square()

然而根据你的定义

def __init__(self, length):
    self.length = length

length是必需的位置参数。您需要为此参数定义合理的默认值，例如

def __init__(self, length=1):
    self.length = length

或在初始化对象时明确提供它（例如s1 = Square(1)）

Answer 4

您应该使用构造函数来传递值。像这样。

s1 = Square(100) 
s2 = Square(482)

Answer 5

您必须提供长度，因为在 init （）所需的长度参数：

s1 = Square(5)
s2 = Square(5)

我的类代码[Python]出了什么问题？

5 个答案:

更新