LeetCode_Valid Tic-Tac-Toe State

class Solution(object):
    def validTicTacToe(self, board):
        
        """
        :type board: List[str]
        :rtype: bool
        """
        
        def win(board, player):
            for i in xrange(3):
                # 행 일치 여부 검사
                if all(board[i][j] == player for j in xrange(3)):
                    return True
                # 열 일치 여부 검사
                if all(board[j][i] == player for j in xrange(3)):
                    return True                   
            # 대각선 검사
            return (player == board[0][0] == board[1][1] == board[2][2]  or
                   player == board[0][2] == board[1][1] == board[2][0])

        FIRST, SECOND = 'X','O'
        
        # x와 o의 개수를 센다
        x_count = sum(row.count(FIRST) for row in board)
        o_count = sum(row.count(SECOND) for row in board)
        print("x_count", x_count)
        print("o_count", o_count)
        
        # 1) x, o 의 개수로 성공 여부를 파악한다 
        if o_count not in [x_count - 1 , x_count]: 
            print("count compare")
            return False
        
        # 2) x 성공 + x개수가 o보다 1만큼 크지 않을때
        if win(board, FIRST) and x_count -1 != o_count : 
            print("x false")
            return False
        
        # 3) o 성공 + o개수가 x랑 같지 않을 때
        if win(board, SECOND) and x_count != o_count : 
            print("o false")
            return False
        
        return True