Danger, Will Robinson! Strange "None"

Hi,

This is my code:

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)
print ship_row
print ship_col

guess_row = int(raw_input("Guess Row: "))
guess_col = int(raw_input("Guess Col: "))

# Write your code below!
if guess_row == ship_row and guess_col == ship_col:
  print "Congratulations! You sank my battleship!"
else: 
  print "You missed my battleship"
  board[guess_row][guess_col] = "X"
  print print_board(board)

When I run it it works fine, but prints “None” at the last line, below the “board”. Is it normal (I don’t beleive) and if not, what is wrong?

Hi, @script4494162026

Next time if you have code you need help with, please remember to use this button to format it for the forums:
image
It makes it easier to read since it includes all your formatting :slight_smile:

As for your code, notice that your print_board() function does not have a return statement. It only prints the board, but does not return it.

Thus, when you write this line:

you are telling your computer to run the print_board() function (which prints the board to the terminal) and print what print_board() returns. Because print_board() has no return statement, it returns nothing. Try calling your function instead of printing it and see what happens.

Happy coding!

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Thank you for your quick and helpful responde. Yes, you are right, that was the problem.

Also appreciate the hint for the formatin. I was wondering how to do it.

No problem! Don’t forget to mark my response as the solution if it helped you solve your problem.

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I have edited your original post to fix the formatting. :slight_smile:

1 Like