title: MineSweeper in Python (With tkinter)
body: <p>I just debugged most of my MineSweeper Code in Python, but there is an issue with the game functions that determine a win or loss. If I win, it does not show the desired message box and confirm a win. If I lose, it will show an error message that says messagebox (a tkinter built in function) is undefined.</p>
  
  <p>This is my code for the game:</p>
  
  <pre><code>from tkinter import *
  import random
  
  ...
  
  def CheckWin(self):
      '''Checks if player won'''
      doneList = []
      for key in self.cells.keys():
          if self.cells[key].clicked == True and self.cells[key].value != 9:
              doneList.append(self.cells[key])
      if len(doneList) == int(height)*int(width)-int(numBombs):
          messagebox.showinfo('Minesweeper','Congratulations -- you won!', parent=self)
          self.winner = True
  
  def CheckLoss(self):
      '''Checks if player lost'''
      self.loser = True
      self.flagTrack['text'] = '0'
      messagebox.showerror('Minesweeper','KABOOM! You lose.', parent=self)
      for key in self.cells.keys():
          if self.cells[key].value == 9:
              self.cells[key].flagged = False
              self.cells[key].expose()
  </code></pre>