調用類中的函數來設置列表的元素

Question

我試圖實現我的第一課，部分是爲了分解建模和解決數學問題的方法，我遇到了麻煩。我認爲我的問題不涉及班級，但是......？

錯誤總是告訴我說：「NameError：全局名稱‘corner2’沒有定義」

我試圖移動函數調用，但它仍然不承認它，所以我把它放回列表聲明在我的init函數中。

這裏是我的代碼：

class RotatedRectangle(object): 

def corner1(a,b): 
    a/=2 
    b/=2 
    x=(a-b)*math.sin(math.pi/4) 
    y=(a+b)*math.sin(math.pi/4) 
    return (x,y) 

def corner2(a,b): 
    a/=-2 
    b/=2 
    x=(a-b)*math.sin(math.pi/4) 
    y=(a+b)*math.sin(math.pi/4) 
    return (x,y) 

def corner3(a,b): 
    a/=-2 
    b/=-2 
    x=(a-b)*math.sin(math.pi/4) 
    y=(a+b)*math.sin(math.pi/4) 
    return (x,y) 

def corner4(a,b): 
    a/=2 
    b/=2 
    x=(a-b)*math.sin(math.pi/4) 
    y=(a+b)*math.sin(math.pi/4) 
    return (x,y) 

def __init__(self, a, b,): 
     """Return a Rotated rectangle object whose name is a function of a and b.""" 
     self.name = str(a) + "," + str(b) + "-rectangle" 
     self.corners = [corner1(a,b), corner2(a,b), corner3(a,b), corner4(a,b)] 



"""A rectangle with sides equal to even integers a and b is drawn on the   Cartesian plane.Its center (the intersection point of its diagonals) coincides with the point (0, 0),but the sides of the rectangle are not parallel to the axes; instead, they are forming 45 degree angles with the axes. 

How many points with integer coordinates are located inside the given rectangle (including on its sides)? """ 

Answer 1

• 你必須使用自己作爲您的類方法
• 致電時類方法的第一個參數在你的課堂內部，你必須傳遞自己作爲他們的第一個參數（以便班級知道你正在談論當前對象）

• 在類中定義方法時必須縮進

  import math 
  class RotatedRectangle(object): 
      def corner1(self,a,b): 
       a/=2 
       b/=2 
       x=(a-b)*math.sin(math.pi/4) 
       y=(a+b)*math.sin(math.pi/4) 
       return (x,y) 
  
      def corner2(self,a,b): 
       a/=-2 
       b/=2 
       x=(a-b)*math.sin(math.pi/4) 
       y=(a+b)*math.sin(math.pi/4) 
       return (x,y) 
  
      def corner3(self,a,b): 
       a/=-2 
       b/=-2 
       x=(a-b)*math.sin(math.pi/4) 
       y=(a+b)*math.sin(math.pi/4) 
       return (x,y) 
  
      def corner4(self,a,b): 
       a/=2 
       b/=2 
       x=(a-b)*math.sin(math.pi/4) 
       y=(a+b)*math.sin(math.pi/4) 
       return (x,y) 
  
      def __init__(self, a, b,): 
       """Return a Rotated rectangle object whose name is a function of a and b.""" 
       self.name = str(a) + "," + str(b) + "-rectangle" 
       self.corners = [self.corner1(a,b), self.corner2(a,b), self.corner3(a,b), self.corner4(a,b)] 
  

Answer 2

你有幾個identation錯誤，你忘記添加self參數，它應該是：

import math 

class RotatedRectangle(object): 
    def __init__(self, a, b,): 
     """Return a Rotated rectangle object whose name is a function of a and b.""" 
     self.name = str(a) + "," + str(b) + "-rectangle" 
     self.corners = [self.corner1(a,b), self.corner2(a,b), self.corner3(a,b), self.corner4(a,b)] 

    def corner1(self,a,b): 
     a/=2 
     b/=2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def corner2(self,a,b): 
     a/=-2 
     b/=2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def corner3(self,a,b): 
     a/=-2 
     b/=-2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def corner4(self,a,b): 
     a/=2 
     b/=2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

我強烈向你推薦閱讀這個問題和所有答案What is the purpose of self?

Answer 3

當在Python中爲類定義方法時，第一個參數通常設置爲「self」。然後，調用該方法時，與self.

這裏前綴是工作代碼：

import math 

class RotatedRectangle(object): 

    def corner1(self,a,b): 
     a/=2 
     b/=2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def corner2(self,a,b): 
     a/=-2 
     b/=2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def corner3(self,a,b): 
     a/=-2 
     b/=-2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def corner4(self,a,b): 
     a/=2 
     b/=2 
     x=(a-b)*math.sin(math.pi/4) 
     y=(a+b)*math.sin(math.pi/4) 
     return (x,y) 

    def __init__(self, a, b,): 
      """Return a Rotated rectangle object whose name is a function of a and b.""" 
      self.name = str(a) + "," + str(b) + "-rectangle" 
      self.corners = [self.corner1(a,b), self.corner2(a,b), self.corner3(a,b), self.corner4(a,b)]