TclError: bad window path name (Python)

Question

In one of the views there is a button for close the actual view, and it works, but when I try to open again the view it shows me the next error:

Exception in Tkinter callback
Traceback (most recent call last):
    File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1545, in __call__
        return self.func(*args)
      File "/home/htm97/Documents/data/workspace/repositories/projects-h/locker-system/src/gui/MainMenu.py", line 27, in verify_lockers_window
        self.app = vl.Lockers(self.vlWindow)
      File "/home/htm97/Documents/data/workspace/repositories/projects-h/locker-system/src/gui/Lockers.py", line 19, in __init__
        self.buttonsList[i].grid(columnspan = 4)
      File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 2032, in grid_configure
        + self._options(cnf, kw))
TclError: bad window path name ".140687059771120.140687059776216.140687059776504.140687059776576"

The function to destroy the window is:

def close_windows(self):                                                                                                                   
    "This function destroys the window"                                                                                                    
    self.master.destroy() 

This is the view:

import Tkinter as tk
class Lockers:
    lockerList = ["1", "2", "3", "4", "5"]
    buttonsList = []

    def __init__(self, master):
        self.master = master
        self.frame = tk.Frame(self.master)
        self.master.minsize(width = 250, height = 200)
        self.initialize_lockers()

        self.frame.grid()

        tk.Label(self.frame, text = "Seleccione el locker que desea revisar:").grid(row = 0, columnspan = 4)

        i = 0
        while i < len(self.lockerList):
            self.buttonsList[i].grid(columnspan = 4) #HERE THE ERROR
            i += 1

        tk.Label(self.frame, text = "").grid(columnspan = 4)
        self.quitButton = tk.Button(self.frame, text = 'Salir', width = 8, command = self.close_windows)
        self.quitButton.grid(column = 1, columnspan = 2)

The function initialize_lockers() appends some buttons to the buttonsList.

After reading a while I've found that after executing destroy() and trying to grid something it will shows an error, but I don't understand why.

Answer 1

The problem was that I had the buttonsList declared outside of the methods, as an attribute, and when I destroy the instance of the class, the attributes disappear, so I had to declare the list inside the constructor, doing this I have no problem with the destroy.