2 player Tic Tac Toe in Python

tictactoe.py

#2-player tic tac toe

# Create the board as a list of empty spaces
board = [" " for i in range(9)]

# print board in terminal
def print_board():
  print("_____________")
  print("|", board[0], "|", board[1], "|", board[2], "|")
  print("-------------")
  print("|", board[3], "|", board[4], "|", board[5], "|")
  print("-------------")
  print("|", board[6], "|", board[7], "|", board[8], "|")
  print("-------------")


# Function to check for winner
def check_winner():
  # Check rows
  for i in range(0, 9, 3):
    if board[i] == board[i + 1] == board[i + 2] != " ":
      return board[i]

  # Check columns
  for i in range(3):
    if board[i] == board[i + 3] == board[i + 6] != " ":
      return board[i]

  # Check diagonals
  if board[0] == board[4] == board[8] != " ":
    return board[0]
  if board[2] == board[4] == board[6] != " ":
    return board[2]

  # No winner
  return None


# Checks if board is full so we can stop on a tie
def is_board_full():
  return " " not in board


# Gameplay loop
def play_game():
  player = "X"
  while True:
    print_board()
    print("Player", player, "turn. Choose a position (1-9):")

    position = input()
    position = int(position) - 1

    if board[position] != " ":
      print("Invalid move. Try again.")
      continue

    board[position] = player

    winner = check_winner()
    if winner:
      print_board()
      print("Player", winner, "wins!")
      break

    if is_board_full():
      print_board()
      print("It's a tie!")
      break

    player = "O" if player == "X" else "X"


# Start the game
play_game()