title: Delete an instance of a class
body: <p>I've already asked a similar question here and I received quite a helpful reply. 
  But since then I've modified my code, now it is more optimized I guess, it is supposed to be more flexible, but the same problem persists. I can not delete an instance of the class.</p>
  
  <p>What I'm trying to do is to create a circle (on a left-click) and then I expect the program to delete the circle (on a right-click).</p>
  
  <pre><code>My code:
  
  from tkinter import *
  
  class Application:
      def __init__(self):
          self.fen = Tk()
          self.fen.title('Rom-rom-roooooom')
          self.butt1 = Button(self.fen, text = ' Quit ', command = self.fen.quit)
          self.can1 = Canvas(self.fen, width = 300, height = 300, bg = 'ivory')
          self.can1.grid(row = 1)
          self.butt1.grid(row = 2)
          self.fen.bind("&lt;Button-1&gt;", self.create_obj)
          self.fen.bind("&lt;Button-3&gt;", self.delete_obj)
          self.fen.mainloop()
      def create_obj(self, event):
          self.d = Oval()
          self.can1.create_oval(self.d.x1, self.d.y1, self.d.x2, self.d.y2, fill='red', width = 2)
      def delete_obj(self, event):
          self.can1.delete(self.d)
  
  
  class Oval:
  
      def __init__(self):
          self.x1 = 50
          self.y1 = 50
          self.x2 = 70
          self.y2 = 70
  
  
  
  appp = Application()
  </code></pre>
  
  <p>so, once again, the problem is that here I can not delete the object:</p>
  
  <pre><code>def delete_obj(self, event):
          self.can1.delete(self.d)
  </code></pre>
  
  <p>One more question. Given the fact that I'm just a begginer I don't know if I chose the right approach as far as class organisation is concerned. Does it look like a well-organized code or should I change anything at this stage already?</p>