title: Adding values to lists in python
body: <p>I have created a simple 8 * 8 grid on python and want to be able to plot 1 "X" to it in the bottom left corner and 10 random "T"'s to it, which I have managed in the code below. The problem being is when I then try and then add a further 5 random "B"s to the grid it sometimes only brings up 4 as I think as it iterates through the list and is not seeing a "-" it is counting as an iteration and when it reaches 5 it is stopping.</p>
  
  <pre><code>from random import randint
  board =[]
  for item in range (0,8):
      board.append(["-"]*8)
  
  def print_board (board):
      for row in board:
          print ("  ".join(row))
  
  treasure = 10
  bandits = 5
  
  def player1(board):
      board[7][0] = 'X'
  
  def random_treasure (board,x):
      for n in range(x):
      treasure_location1 = randint(0, len(board)-1)
      treasure_location2 = randint(0, len(board)-1)
      board[treasure_location1][treasure_location2]
  
          while board[treasure_location1][treasure_location2] == "X" or board[treasure_location1][treasure_location2] == "T":
          treasure_location1 = randint(0, len(board)-1)
          else:
              board[treasure_location1][treasure_location2] = 'T'
  
  def random_bandits (board,y):
      for n in range(y):
          global treasure_location1
          global treasure_location2
          bandit_location1 = randint(0, len(board)-1)
          bandit_location2 = randint(0, len(board)-1)
          board[bandit_location1][bandit_location2]
  
          while board[bandit_location1][bandit_location2] == "X" or board[bandit_location1][bandit_location2] == "T":
          bandit_location1 = randint(0, len(board)-1)
          else:
              board[bandit_location1][bandit_location2] = "B"
  
  
  player1(board)
  random_treasure(board,treasure)
  random_bandits (board,bandits)
  
  print_board(board)
  </code></pre>
  
  <p>I thought doing something like this would be more efficient and thus will simply only print a T or B to the board if it sees a "-" but it is only printing one T not the range I want. I know this is probably some simple logic error but I am a bit stuck so any help is appreciated, thanks</p>
  
  <pre><code>def random_treasure (board,x):
      treasure_location1 = randint(0, len(board)-1)
      treasure_location2 = randint(0, len(board)-1)
      board[treasure_location1][treasure_location2]
  
      while board[treasure_location1][treasure_location2] == "-":
          for n in range(x):
              board.append("T")
  </code></pre>