給定類的對象可調用一次，但不能再次

Question

我的代碼運行良好，只有一個矩形，但只要我添加第二個矩形，它就會說「'點'對象不可調用」，儘管已成功調用第一個矩形。我已經對矩形上的不同變化進行了足夠多的測試，得出結論：唯一的原因是它現在正在嘗試創建多個矩形。任何人都可以幫忙嗎？

下面是代碼的開始，它用於定義不同的元素及其參數。

import matplotlib.pyplot as plt 
import numpy 

elementset = [] 
pointxs = [] 
pointys = [] 

class point(object): 
    """General point in 2d space, with stored x value and y value. 
    Created and used in elements to give them shape. 
    """ 

    def __init__(self, x, y): 
     self.x = float(x) 
     self.y = float(y) 
     self.isAnchor = False 

    def __repr__(self): 
     return "(%d, %d)" % (self.x, self.y) 

class element(object): 
    """Most general class used to define any element to be used in 
    the cross-section being worked with. Used as a basis for more 
    specific classes. Has a coordinate value and a number of points that 
    need to be generated for the general case. 
    """ 

    def __init__(self, anchor_x, anchor_y): 
     self.num_points = 0 
     self.anchor_x = float(anchor_x) 
     self.anchor_y = float(anchor_y) 
     elementset.append(self) 

    def getinfo(self): 
     """Used for debugging, prints all general info for the element. 
     Never called in the actual code.""" 
     print "Number of points: " + str(self.num_points) 
     print "x coordinate: " + str(self.anchor_x) 
     print "y coordinate: " + str(self.anchor_y) 

    def debug(self): 
     self.getinfo() 

class rectangle(element): 
    """A rectangle, assumed to be aligned such that all sides are 
    either vertical or horizontal. Calls/assigns variables 
    created in the element class via super(). 
    """ 

    def __init__(self, anchor_x, anchor_y, width, height): 
     super(rectangle, self).__init__(anchor_x, anchor_y) 
     self.title = "rectangle" 
     self.num_points = 4 
     self.width = float(width) 
     self.height = float(height) 
     self.generate() 
     self.calculate() 

    def generate(self): 
     """Creates the points that frame the rectangle using coordinates. 
     For a rectangle, the anchor point represents the bottom left point.""" 
     self.anchor = point(self.anchor_x, self.anchor_y) 
     self.pointxpos = point(self.anchor_x + self.width, self.anchor_y) 
     self.pointxypos = point(self.anchor_x + self.width, self.anchor_y + self.height) 
     self.pointypos = point(self.anchor_x, self.anchor_y + self.height) 
     self.points = [self.anchor, self.pointxpos, self.pointxypos, self.pointypos] 
     self.plotpoints = [self.anchor, self.pointxpos, self.pointxypos, self.pointypos, self.anchor] 

這裏是調用這些（只有1矩形定義）功能：

ar = rectangle(0,0,50,20) 

for element in elementset: 
    if isinstance(element,rectangle): 
     element.generate() 
     for point in element.plotpoints: 
      pointxs.append(point.x) 
      pointys.append(point.y) 
     plt.plot(pointxs,pointys, linewidth=3) 

    elif isinstance(element,square): 
     pass #placeholder 
    elif isinstance(element,circle): 
     pass #placeholder 
    elif isinstance(element,semicircle): 
     pass #placeholder 

plt.show() 

這是成功的，在（0,0）密謀用左下角一個50x20的長方形。

但如果我是添加另一元件之下AR：

ar = rectangle(0,0,50,20) 
br = rectangle(50,20,10,10) 

它拋出「‘點’對象不是可調用」。 我真的被這個難住了，所以提前謝謝你的幫助。

Answer 1

我想知道爲什麼這對第一個矩形甚至是成功的。原因可能是你沒有顯示真實的minimal complete verifiable example。

在任何情況下，問題都如此簡單：切勿對類使用與（循環）變量相同的名稱。

I.e.以下作品：

ar = rectangle(0,0,50,20) 
br = rectangle(23,16,22,13) 

elementset.append(ar) 
elementset.append(br) 

for elefant in elementset: 
    if isinstance(elefant,rectangle): 
     elefant.generate() 
     for wombat in elefant.plotpoints: 
      pointxs.append(wombat.x) 
      pointys.append(wombat.y) 
     plt.plot(pointxs,pointys, linewidth=3) 

...除了所有的對象將通過一條線連接的事實，但這可能是一個不同的問題。