# Tuple to store winning positions.
win_positions = (
    (0, 1, 2), (3, 4, 5), (6, 7, 8),
    (0, 3, 6), (1, 4, 7), (2, 5, 8),
    (0, 4, 8), (2, 4, 6)
)
 
def game(player):
    # diplay current mesh
    print("\n", " | ".join(mesh[:3]))
    print("---+---+---")
    print("", " | ".join(mesh[3:6]))
    print("---+---+---")
    print("", " | ".join(mesh[6:]))
 
    # Loop until player valid input cell number.
    while True:
        try:
            ch = int(input(f"Enter player {player}'s choice : "))
            if str(ch) not in mesh:
                raise ValueError
            mesh[ch-1] = player
            break
        except ValueError:
            print("Invalid position number.")
 
    # Return winning positions if player wins, else None.
    for wp in win_positions:
        if all(mesh[pos] == player for pos in wp):
            return wp
    return None

player1 = "X"
player2 = "O"
player = player1
mesh = list("123456789")
 
for i in range(9):
	won = game(player)
	if won:
		print("\n", " | ".join(mesh[:3]))
		print("---+---+---")
		print("", " | ".join(mesh[3:6]))
		print("---+---+---")
		print("", " | ".join(mesh[6:]))
		print(f"*** Player {player} won! ***")
		break
	player = player1 if player == player2 else player2
else:
    # 9 moves without a win is a draw.
    print("Game ends in a draw.")