python 井字棋

if len(c_poss)==9:

        return random.choice([0,2,6,8])

    elif len(c_poss)==8:

        if 4 in c_poss:

            return 4

        for i in [0,2,6,8]:

            if i in c_poss:

                return i

    for x in c_poss:

        if is_win(place(board,x,player),player):

            return x

    for y in c_poss:

        if is_win(place(board,y,3-player),3-player):

            return y

    return random.choice(c_poss)