Algorithm for solving Sudoku

Question

I want to write a code in python to solve a sudoku puzzle. Do you guys have any idea about a good algorithm for this purpose. I read somewhere in net about a algorithm which

Answer 1

a short attempt to achieve same algorithm using backtracking:

def solve(sudoku):
    #using recursion and backtracking, here we go.
    empties = [(i,j) for i in range(9) for j in range(9) if sudoku[i][j] == 0]
    predict = lambda i, j: set(range(1,10))-set([sudoku[i][j]])-set([sudoku[y+range(1,10,3)[i//3]][x+range(1,10,3)[j//3]] for y in (-1,0,1) for x in (-1,0,1)])-set(sudoku[i])-set(list(zip(*sudoku))[j])
    if len(empties)==0:return True
    gap = next(iter(empties))
    predictions = predict(*gap)
    for i in predictions:
        sudoku[gap[0]][gap[1]] = i
        if solve(sudoku):return True
        sudoku[gap[0]][gap[1]] = 0
    return False