jogo da velha python erro

|Estou tendo problema em resolver um problema quando a cpu joga, na 2ª jogada as vezes ela joga 2 vezes. Não consegui resolver se puderem me ajudar eu agradeço.

Nova = "S"

while Nova == "S":

import random

t = '''

{0} | {1} | {2}

---+---+---

{3} | {4} | {5}

---+---+---

{6} | {7} | {8}

'''

cont1=0;cont2=0 ; vet=[]

def print_board(t): #função imprime o tabuleiro com as marcações atuais

print ("""

1 | 2 | 3

---+---+---

4 | 5 | 6

---+---+---

7 | 8 | 9

""")

print (t.format(mt[0][0],mt[0][1],mt[0][2],mt[1][0],mt[1][1],mt[1][2],mt[2][0],mt[2][1],mt[2][2]))

def mark(play,mark):    #função marca no tabuleiro a posição escolhida

if play == '1':

mt[0][0] = mark

elif play == '2':

mt[0][1] = mark

elif play == '3':

mt[0][2] = mark

elif play == '4':

mt[1][0] = mark

elif play == '5':

mt[1][1] = mark

elif play == '6':

mt[1][2] = mark

elif play == '7':

mt[2][0] = mark

elif play == '8':

mt[2][1] = mark

elif play == '9':

mt[2][2] = mark

def end_game(a,b,c,d,e,f): #função determina se alguém ganhou o jogo

if mt[a] == 'X' and mt[c][d] == 'X' and mt[e][f] == 'X':
**
                winner = 'Player'**
**
                vet.append(winner)**
**
            if mt[a]** == 'O' and mt[c][d] == 'O' and mt[e][f] == 'O':
**
                winner = 'CPU'**
**
                vet.append(winner)**
**
            else:**
**
                winner = 'Deu velha'**
**
                vet.append(winner)**
**
        **
**
        
**

**

****
    def s_play(a,b,c,d,play,e,f):  #algoritimo da segunda jogada do cpu (bloqueia a jogada do adversário)**
**
        if mt[a]** == mt[c][d] and mt[a] == 'X':
**
            if mt[e][f] == ' ' :**
**
                playcpu = play**
**
                mark(play,'O')**
**
                cont3=1**
**
            **
**
            else:**
**
                playcpu = 'blank'**
**
            return playcpu **
**
            **
**
    **
**
    winner = ''**
**
    cont = 0 #contador do número d jogadas**
**
    quad_left = ['1','4','7','2','5','8','3','6','9'] #lista dos quadrantes livres**
**
    c_left = ['1','7','3','9']**
**
    c_left2 = ['8','2','6']**
**
    mt = [[' ',' ',' '],[' ',' ',' '],[' ',' ',' ']] #matriz do tabuleiro
**

**

****
    print_board(t)**
**
    #jogar=input('Digite S para continuar o jogo')**
**
    cont = 0**
**
    #while jogar=='S':   **
**
    while cont <= 9 :**
**
        playp =input('Escolha o quadrante em que deseja marcar:').upper()**
**
        while playp not in quad_left:**
**
            print ('Quadrante Inválido!\n')**
**
            playp = input('Escolha o quadrante em que deseja marcar:').upper()**
**
        mark(playp,'X')**
**
        cont = 1+cont**
**
        quad_left.remove(playp)**
**
        try:**
**
            c_left.remove(playp)**
**
        except:**
**
            playp not in c_left**
**
        print_board(t)
**

**

****
**
**
        if cont == 1:**
**
            print ('Jogada do adversário:')**
**
            if playp == '1':**
**
                playcpu = '9'**
**
                mark(playcpu,'O')**
**
            elif playp == '9':**
**
                playcpu = '1'**
**
                mark(playcpu,'O')**
**
            elif playp == '7':**
**
                playcpu = '3'**
**
                mark(playcpu,'O')**
**
            elif playp == '3':**
**
                playcpu = '7'**
**
                mark(playcpu,'O')**
**
            else:**
**
                playcpu = random.choice(c_left)**
**
                mark(playcpu,'O')**
**
            cont += 1**
**
            quad_left.remove(playcpu)**
**
            c_left.remove(playcpu)**
**
            print_board(t)**
**
            print (playcpu)**
**
        **
**
        if cont==3 or cont==5 or cont==7:**
**
            print ('Jogada do adversário:')**
**
            count1=0**
**
            for i in range (0,3):**
**
              for j in range (0,3):  **
**
                if mt***.count('O')==1 and mt**.count('X')==0:*
***
                     s_play(i,0,2,0,'1',0,0)***
***
                     s_play(i,1,1,2,'4',1,0)***
***
                     s_play(i,1,2,1,'2',0,1)***
***
                     s_play(i,0,1,2,'5',1,1)***
***
                     s_play(i,2,2,2,'3',0,2)***
***
                     s_play(i,0,1,1,'6',1,2)***
***
                #else:***
***
                     playcpu = random.choice(quad_left)***
***
                     mark(playcpu,'O')***
***
                    #print (playcpu)***
***
                     break***
***
                if mt[j]****=='O':*
***
                    count1=count1+1***
***
                    if count1==2:***
***
                         s_play(i,0,j,0,'1',0,0)***
***
                         s_play(i,1,j,2,'4',1,0)***
***
                         s_play(i,1,j,1,'2',0,1)***
***
                         s_play(i,0,j,2,'5',1,1)***
***
                         s_play(i,2,j,2,'3',0,2)***
***
                         s_play(i,0,j,1,'6',1,2)***
***
                         break***
***
                ***
***
        ***
***
                else:***
***
                     s_play(1,0,2,0,'1',0,0)***
***
                     s_play(0,1,0,2,'1',0,0)***
***
                     s_play(2,2,1,1,'1',0,0)***
***
                     s_play(0,0,2,0,'4',1,0)***
***
                     s_play(1,1,1,2,'4',1,0)***
***
                     s_play(2,2,2,1,'4',1,0)***
***
                     s_play(0,2,1,1,'7',2,0)***
***
                     s_play(2,1,2,2,'7',2,0)***
***
                     s_play(0,0,1,0,'7',2,0)***
***
                     s_play(0,1,1,1,'8',2,1)***
***
                     s_play(1,1,2,1,'2',0,1)***
***
                     s_play(0,0,0,2,'2',0,1)***
***
                     s_play(1,0,1,2,'5',1,1)***
***
                     s_play(0,1,2,1,'5',1,1)***
***
                     s_play(2,0,2,2,'8',2,1)***
***
                     s_play(0,2,2,0,'5',1,1)***
***
                     s_play(0,0,2,2,'5',1,1)***
***
                     s_play(0,2,1,2,'9',2,2)***
***
                     s_play(1,2,2,2,'3',0,2)***
***
                     s_play(0,0,0,1,'3',0,2)***
***
                     s_play(1,0,1,1,'6',1,2)***
***
                     s_play(2,0,2,1,'9',2,2)***
***
                     s_play(2,0,1,1,'3',0,2)***
***
                     s_play(0,0,1,1,'9',2,2)***
***
                     s_play(0,0,1,1,'3',0,2)***
***
                     s_play(0,2,2,2,'6',1,2)***
***
                     break***
***
            cont += 1***
***
            print_board(t)***
***
            print (playcpu)
***

***

******
  #      else:***
***
    #        playcpu = random.choice(quad_left)***
***
      #      mark(playcpu,'O')***
***
       #     print (playcpu)***
***
        ***
***
        if cont >=4:***
***
                end_game(0,0,0,1,0,2)***
***
                end_game(1,0,1,1,1,2)***
***
                end_game(2,0,2,1,2,2)***
***
                end_game(0,0,1,0,2,0)***
***
                end_game(0,1,1,1,2,1)***
***
                end_game(0,2,1,2,2,2)***
***
                end_game(0,0,1,1,2,2)***
***
                end_game(2,0,1,1,0,2)***
***
        #else:***
***
                playcpu = random.choice(quad_left)***
***
                mark(playcpu,'O')***
***
                print (playcpu)***
***
           ***
***
        if vet.count('Player')>=1:***
***
                winner='Player'***
***
                break***
***
        if vet.count('CPU')>=1:***
***
                winner='CPU'***
***
                break***
***
        else:***
***
                winner='Deu velha'***
***
        if cont==9:***
***
            break***
***
    ***
***
    print (winner)***
***
    Nova = input("Para jogar novamente digite S ")***
***
    print ("--------------------------------------")***
***
 
***