My Minesweeper program written in Python is revealing the whole board - Recursion issues

Question

I'm trying to write a Minesweeper program using Python. Everything is working fine except for my cascading reveal. Here is what I have:

def rippleEffect(self, r, c):
     if self.ActualBoard[r][c] == 0:
      self.GameBoard[r][c] = self.ActualBoard[r][c]
      rcchar = str(sum(1
                      for rr in (r-1, r, r+1)
                      for cc in (c-1, c, c+1)))
      for rr in (r-1, r, r+1):
        for cc in (c-1, c, c+1):
          if self.ActualBoard[rr][cc] != 'M' and self.ActualBoard[rr][cc] > 0:
            self.GameBoard[rr][cc] = self.ActualBoard[rr][cc]
          else:
            try:
              if (rr,cc) != (r,c) and self.GameBoard[rr][cc] == 'H':
                self.rippleEffect(rr, cc)
            except IndexError: 
              pass

ActualBoard consists of list of lists with everything revealed, ie:

[[0, 1, 1, 1], [0, 1, M, 1], [0, 1, 1, 1], [0, 0, 0, 0]]

for a 4x4 board with one mine.

GameBoard consists of a list of lists as well but when the game starts it would look like so:

[['H','H', 'H', 'H'], ['H','H', 'H', 'H'], ['H','H', 'H', 'H'], ['H','H', 'H', 'H']]

Answer 1

Think about this: if r == 0 and c == 0, what will self.GameBoard[r-1][c-1] be? More specifically, would it raise an IndexError?