PuzzleLogic.py

import numpy as np

# currently using an example Sudoku puzzle
# Grid needs to be the Sudoku puzzle you want to solve
grid = [[5,3,0,0,7,0,0,0,0],[6,0,0,1,9,5,0,0,0],[0,9,8,0,0,0,0,6,0],[8,0,0,0,6,0,0,0,3],[4,0,0,8,0,3,0,0,1],[7,0,0,0,2,0,0,0,6],[0,6,0,0,0,0,2,8,0],[0,0,0,4,1,9,0,0,5],[0,0,0,0,8,0,0,7,9]]

def checkSquare(y,x,n):
    global grid
    for i in range(0,9):
        if grid[y][i] == n:
            return False
    for i in range(0,9):
        if grid[i][x] == n:
            return False
    x0 = (x//3)*3
    y0 = (y//3)*3
    for i in range(0,3):
        for j in range(0,3):
            if grid[y0+i][x0+j] == n:
                return False
    return True

def solvePuzzle():
    global grid
    for y in range(9):
        for x in range(9):
            if grid[y][x] == 0:
                for n in range(1,10):
                    if checkSquare(y,x,n):
                        grid[y][x] = n
                        solvePuzzle()
                        grid[y][x] = 0
                return
    print(np.array(grid, dtype=object))
    print("done")
    #input("Another?")

solvePuzzle()