main.py

import random
import sys

print("Welcome to my first game!")
name = input("Enter your name: ")
age = input("What is your age? ")

print("Hello", name ,"you are", age, "years old")

'''Checking the player's age'''

if int(age) < 5:
    print("You are not allowed to play the game!")
  
else:
    print("You are allowed to play the game!")

    board=[i for i in range(0,9)]
    player, computer = '',''

    # Corners, Center and Others, respectively
    moves=((1,7,3,9),(5,),(2,4,6,8))
    # Winner combinations
    winners=((0,1,2),(3,4,5),(6,7,8),(0,3,6),(1,4,7),(2,5,8),(0,4,8),(2,4,6))
    # Table
    tab=range(1,10)

    def print_board():
        x=1
        for i in board:
            end = ' | '
            if x%3 == 0:
                end = ' \n'
                if i != 1: end+='---------\n';
            char=' '
            if i in ('X','O'): char=i;
            x+=1
            print(char,end=end)
            
    def select_char():
        chars=('X','O')
        if random.randint(0,1) == 0:
            return chars[::-1]
        return chars

    def can_move(brd, player, move):
        if move in tab and brd[move-1] == move-1:
            return True
        return False

    def can_win(brd, player, move):
        places=[]
        x=0
        for i in brd:
            if i == player: places.append(x);
            x+=1
        win=True
        for tup in winners:
            win=True
            for ix in tup:
                if brd[ix] != player:
                    win=False
                    break
            if win == True:
                break
        return win

    def make_move(brd, player, move, undo=False):
        if can_move(brd, player, move):
            brd[move-1] = player
            win=can_win(brd, player, move)
            if undo:
                brd[move-1] = move-1
            return (True, win)
        return (False, False)

    # AI goes here
    def computer_move():
        move=-1
        # If I can win, others don't matter.
        for i in range(1,10):
            if make_move(board, computer, i, True)[1]:
                move=i
                break
        if move == -1:
            # If player can win, block him.
            for i in range(1,10):
                if make_move(board, player, i, True)[1]:
                    move=i
                    break
        if move == -1:
            # Otherwise, try to take one of desired places.
            for tup in moves:
                for mv in tup:
                    if move == -1 and can_move(board, computer, mv):
                        move=mv
                        break
        return make_move(board, computer, move)

    def space_exist():
        return board.count('X') + board.count('O') != 9

    player, computer = select_char()
    print('Player is [%s] and computer is [%s]' % (player, computer))
    result='%%% Deuce ! %%%'
    while space_exist():
        print_board()
        print('# Make your move ! [1-9] : ', end='')
        move = int(input())
        moved, won = make_move(board, player, move)
        if not moved:
            print(' >> Invalid number ! Try again !')
            continue
        #
        if won:
            result='*** Congratulations ! You won ! ***'
            break
        elif computer_move()[1]:
            result='=== You lose ! =='
            break;

    print_board()
    print(result)