Backtracking sudoku solver

sudoku.py

# Sudoku puzzle solver

def make_sudoku_board():
    return [
            [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 print_board(board):
    for row in board:
        for col in row:
            print(col, end=" ")
        print()


def solve(board):

    def get_nums(row, col):
        nums = [i for i in range(1, 10)]
        # eliminate nums from row
        for r in board[row]:
            try:
                nums.remove(r)
            except:
                pass
        # eliminate nums from col
        for r in board:
            try:
                nums.remove(r[col])
            except:
                pass
        # eliminate nums from matrix
        mat_row = 3 * (row // 3)
        mat_col = 3 * (col // 3)
        for i in range(mat_row, mat_row + 3):
            for j in range(mat_col, mat_col + 3):
                try:
                    nums.remove(board[i][j])
                except:
                    pass
        return nums

    def _solve(row, col):
        if row == 9 and col == 0:
            print("\nSOLUTION:")
            print_board(board)
        elif board[row][col] == 0:
            for t in get_nums(row, col):
                # choose
                board[row][col] = t
                # explore
                _solve(row if col < 8 else row + 1, (col + 1) % 9)
                # unchoose
                board[row][col] = 0
        else:
            _solve(row if col < 8 else row + 1, (col + 1) % 9)

    _solve(0, 0)


if __name__ == '__main__':
    board = make_sudoku_board()
    print_board(board)
    solve(board)

Output

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 

SOLUTION:
5 3 4 6 7 8 9 1 2 
6 7 2 1 9 5 3 4 8 
1 9 8 3 4 2 5 6 7 
8 5 9 7 6 1 4 2 3 
4 2 6 8 5 3 7 9 1 
7 1 3 9 2 4 8 5 6 
9 6 1 5 3 7 2 8 4 
2 8 7 4 1 9 6 3 5 
3 4 5 2 8 6 1 7 9