tic tac toe

xo.py

import random

def display_board(a_board):
    print(a_board[7] + '|' + a_board[8] + '|' + a_board[9])
    print('-'*5)
    print(a_board[4] + '|' + a_board[5] + '|' + a_board[6])
    print('-'*5)
    print(a_board[1] + '|' + a_board[2] + '|' + a_board[3])

    
def player_input():
    player_choice = ''
    while not (player_choice == 'X' or player_choice == 'O'):
        player_choice = input('Human, choose your marker: X or O: ').upper()

    if player_choice == 'X':
        return ('O', 'X')
    else:
        return ('X', 'O')


def place_marker(a_board, a_marker, a_position):
    a_board[a_position] = a_marker


def win_check(a_board, a_marker):
    return (a_board[1] == a_board[2] == a_board[3] == a_marker or
            a_board[4] == a_board[5] == a_board[6] == a_marker or
            a_board[7] == a_board[8] == a_board[9] == a_marker or
            a_board[1] == a_board[4] == a_board[7] == a_marker or
            a_board[2] == a_board[5] == a_board[8] == a_marker or
            a_board[3] == a_board[6] == a_board[9] == a_marker or
            a_board[1] == a_board[5] == a_board[9] == a_marker or
            a_board[3] == a_board[5] == a_board[7] == a_marker)


def space_check(a_board, a_position):
    return a_board[a_position] == ' '


def full_board_check(a_board):
    return ' ' in a_board


def player_choice(a_board):
    chosen_position = int(input('Choose your desired position: '))
    while space_check(a_board, chosen_position) == False:
        chosen_position = int(input('Choose your desired position: '))
    return chosen_position

def ai_choice(a_board):
    chosen_position = random.randint(1,9)
    while space_check(a_board, chosen_position) == False:
        chosen_position = random.randint(1,9)
    return chosen_position


def replay():
    return input('Play again? Y/N: ').upper() == 'Y'



      
print('Welcome to Tic Tac Toe!')

while True:
    
    the_board = ['#',' ',' ',' ',' ',' ',' ',' ',' ',' ']
    ai_marker, h_marker = player_input()
    game_on = True
    turn = 'ai_player'

    while game_on:
        
        if turn == 'ai_player':
            selected_position = ai_choice(the_board)
            place_marker(the_board, ai_marker, selected_position)

            if win_check(the_board, ai_marker) == True:
                display_board(the_board)
                print('AI wins!')
                game_on = False
            elif full_board_check(the_board) == False:
                display_board(the_board)
                print('Tie')
                game_on = False
            else:
                turn = 'h_player'      
        
        elif turn == 'h_player':
            display_board(the_board)
            selected_position = player_choice(the_board)
            place_marker(the_board, h_marker, selected_position)

            if win_check(the_board, h_marker) == True:
                display_board(the_board)
                print('Human wins!')
                game_on = False
            elif full_board_check(the_board) == False:
                display_board(the_board)
                print('Tie')
                game_on = False
            else:
                turn = 'ai_player'

    if not replay():
        break