# 14. Test Run - Index Error following guesses out of range

#1

Whenever I guess out of range I get the following message:

Traceback (most recent call last):
File "python", line 31, in
IndexError: list index out of range

Where line 31 is ** highlighted ** below. I can't figure out what I have done wrong, please help!

``````from random import randint

board = []

for x in range(0, 5):
board.append(["O"] * 5)

def print_board(board):
for row in board:
print " ".join(row)

print_board(board)

def random_row(board):
return randint(0, len(board) - 1)

def random_col(board):
return randint(0, len(board[0]) - 1)

ship_row = random_row(board)
ship_col = random_col(board)
guess_row = int(raw_input("Guess Row:"))
guess_col = int(raw_input("Guess Col:"))

print ship_row
print ship_col

if guess_row == ship_row and guess_col == ship_col:
print "Congratulations! You sank my battleship!"
**elif (board[guess_row][guess_col] == "X"):**
print "You guessed that one already."
else:
print "You missed my battleship!"
board[guess_row][guess_col] = "X"
print_board(board)
if guess_row not in range(5) or \
guess_col not in range(5):
print "Oops, that's not even in the ocean."
else:
print "You missed my battleship!"
board[guess_row] = "X"
board[guess_col] = "X"
print_board(board)``````

14. Test Run - index error, out of range
#2

Compare mine with yours. Mine is working.

``````def random_row(board):
return randint(0, len(board) - 1)

def random_col(board):
return randint(0, len(board[0]) - 1)

ship_row = random_row(board)
ship_col = random_col(board)
guess_row = int(raw_input("Guess Row:"))
guess_col = int(raw_input("Guess Col:"))

print ship_row
print ship_col

if guess_row == ship_row and guess_col == ship_col:
print "Congratulations! You sank my battleship!"
else:
if  guess_row not in range(5) or \
guess_col not in range(5):
print "Oops, that's not even in the ocean."
elif board[guess_row][guess_col] == "X":
print "You guessed that one already."
else:
print "You missed my battleship!"
board[guess_row][guess_col] == "X"
print print_board(board)``````

#3

aha! your elif is in the wrong place.

(1) if (now, here)

(2) else
---- if
---- elif ( should be here!)
---- else

#4

Aha, thank you! Appreciate the help!

#5

This is correct except you need one "=" here instead of "==".

``    board[guess_row][guess_col] **=** "X"``

#6

Thanks. But I wandered why. Is it because if it's the first time missing it, mark it as "X", and compare it later using ==?

``````elif board[guess_row][guess_col] == "X":
print "You guessed that one already."
else:
print "You missed my battleship!"
board[guess_row][guess_col] = "X"``````

#7

If the first elif, you're comparing it to "X" so that's why it's double =. In the else, you are setting it to "X" so there's a single =

Hope this helps!