I develp a TicTacToe game with PyQt5 and I have a problem with the vinqueur(winner)func. This func always returns 0, even if one of the players wins

Question

I am developing a TicTacToe gamebetween humin and machine(using algorithm minmax) with PyQt5 contain: def bouton (to create a grid),def vinquer(to chek the winner)def minmax and machine , Ithink i have a problem with the "vinqueur"(winner)func. This func always returns zero, even if one of the players wins. help me please to resolv this issue.

%tb
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys

class Tic_tac_toe(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setGeometry(300,100,400,600)  
        self.a=3
        self.Boutton()
        self.show()
        
    def Boutton(self):
        self.grille=[]
        self.joueur = -1
      
        for _ in range(self.a):
            ligne = []
            for _ in range(self.a):
                ligne.append((QPushButton(self)))
            self.grille.append(ligne)
        
        for i in range(self.a):
            for j in range(self.a):
                self.grille[i][j].setGeometry(90*i + 20,90*j + 20,80, 80)

                # setting font to the button
                self.grille[i][j].setFont(QFont(QFont('Times', 17)))

                # adding action
                self.grille[i][j].clicked.connect(self.Actions)
                

    def vinqueur(self):
        # checking if any row crossed
        for i in range(3):
            if self.grille[0][i].text() == self.grille[1][i].text() \
            and self.grille[0][i].text() == self.grille[2][i].text() \
            and self.grille[0][i].text() != "": 
                if self.grille[0][i].text() == "X":return -1
                if self.grille[0][i].text() == "O":return 1
        # checking if any column crossed
        for i in range(3):
            if self.grille[i][0].text() == self.grille[i][1].text() \
            and self.grille[i][0].text() == self.grille[i][2].text() \
            and self.grille[i][0].text() != "":
                if self.grille[i][0].text() == "X":return -1
                if self.grille[i][0].text() == "O":return 1

        # checking if diagonal crossed
        if self.grille[0][0].text() == self.grille[1][1].text() \
        and self.grille[0][0].text() == self.grille[2][2].text() \
        and self.grille[0][0].text() != "":
            if self.grille[0][0].text() == "X":return -1
            if self.grille[0][0].text() == "O":return 1

        # if other diagonal is crossed
        if self.grille[0][2].text() == self.grille[1][1].text() \
        and self.grille[1][1].text() == self.grille[2][0].text() \
        and self.grille[0][2].text() != "":
            if self.grille[0][2].text() == "X":return -1
            if self.grille[0][2].text() == "O":return 1
        return 0
        
        

    
    def Actions(self):
        
        if self.joueur==-1:
            button = self.sender()
            button.setEnabled(False)
            button.setText("X")
            self.joueur=1
        
        
        if self.joueur==1:
            self.machine()
            self.joueur=-1
            
        

        #self.tour = self.Tour() à vérifier si tu doit la remettre ou non

            # setting text to the label
            #self.label.setText(message)
    def mini_max(self, joueur):
        x=self.vinqueur()
        if x != 0:
            return x*joueur
        x,y=-1,-1
        meilleur_score=-10
        for i in range(self.a):
            for j in range(self.a):
                if self.grille[i][j].text() == "":
                    if joueur==(-1):
                        self.grille[i][j].setText("x")
                    else:self.grille[i][j].setText("o")
                    score = -self.mini_max(joueur*-1)
                    if score>meilleur_score:
                        meilleur_score = score
                        x,y=i,j
                    self.grille[i][j].setText("")
            if (x,y)==(-1,-1): return 0  

            return meilleur_score
    
    def machine(self):
        meilleur_score = -10
        x, y = -1, -1
        for i in range(self.a):
            for j in range(self.a):
                if self.grille[i][j].text() == "":
                    self.grille[i][j].setText("O")
                    score = -self.mini_max(-1)
                    self.grille[i][j].setText("")
                    if score > meilleur_score:
                        meilleur_score = score
                        x, y = i, j
        self.grille[x][y].setText("O")
        self.grille[x][y].setEnabled(False)
    
App = QApplication(sys.argv)

# create the instance of our Window
tic_Tac_Toe = Tic_tac_toe()

# start the app
sys.exit(App.exec())