How to create lists of 3x3 sudoku block in python

Question

I need help creating a list for each of the 9 3x3 blocks in sudoku. so I have a list of lists representing the original sudoku board (zero means empty):

board=[[         


        

Answer 1

this uses no builtins and is faster 3 nested for loops

def get_boxes(board):
    boxes = []
    for i in range(9): 
        if i == 0 or i % 3 == 0:  
            box_set_1 = board[i][:3] + board[i + 1][:3] + board[i + 2][:3]  
            boxes.append(box_set_1)
            box_set_2 = board[i][3:6] + board[i + 1][3:6] + board[i + 2][3:6]
            boxes.append(box_set_2)
            box_set_3 = board[i][6:] + board[i + 1][6:] + board[i + 2][6:]
            boxes.append(box_set_3)