怎样解数独？

Python

def setBoardFunc(puz):
    global grid
    print("Original Sudoku")
    for i in range(0, len(puz), 9):
        row = puz[i:i+9]
        temp = []
        for block in row:
            temp.append(int(block))
        grid.append(temp)
    printGridFunc()

def printGridFunc():
    global grid
    for row in grid:
        print(row)

def checkValidFunc(row, column, num):
    global grid
    for i in range(9):
        if grid[row][i] == num or grid[i][column] == num:
            return False
    square_row, square_col = (row // 3) * 3, (column // 3) * 3
    for i in range(3):
        for j in range(3):
            if grid[square_row + i][square_col + j] == num:
                return False
    return True

def solveFunc(solutions_count=1):
    global grid
    solutions_found = 0  # 计数器，用于记录已找到的解的数量
    
    def solve():
        nonlocal solutions_found
        for row in range(9):
            for column in range(9):
                if grid[row][column] == 0:
                    for num in range(1, 10):
                        if checkValidFunc(row, column, num):
                            grid[row][column] = num
                            solve()
                            grid[row][column] = 0  # 回溯
                    return
        # 当所有空格都被填满时，找到了一个解
        solutions_found += 1
        print(f'\nSolution {solutions_found} to Sudoku Problem')
        printGridFunc()
        if solutions_found >= solutions_count:  # 如果找到了指定数量的解，则停止搜索
            raise StopIteration  # 使用异常来退出递归
    
    try:
        solve()
    except StopIteration:
        pass  # 捕获异常以优雅地结束递归

# 设置谜题和求解
puz = "800000000003600000070090200050007000000045700000100030001000068008500010090000400"
grid = []
setBoardFunc(puz)
solveFunc(solutions_count=2)  # 更改这里的数字来设置输出的解的数量