def sudoku_to_string(sudoku):
    s = " "
    x = ""
    for row in sudoku:
        x += s.join(str(item) for item in row) + "\n"
    x = x.replace("0", ".")
    x = x.strip()
    return x


def is_in_row(sudoku, i):
    l = [0,1,2,3,4,5,6,7,8,9]
    x = [item for item in l if item not in sudoku[i]]

    m = []
    for i in range(0,10):
        m.append(i not in x)
    return m




def is_in_column(sudoku, j):
    pass
    l = [0,1,2,3,4,5,6,7,8,9]
    x=[]
    xx = []
    xxx = []

    for i in range(len(sudoku)):
        x.append(sudoku[i][j])

    xx = [item for item in l if item not in x]

    for i in range(0,10):
        xxx.append(i not in xx)
    return xxx


def square_indices(i, j):
    x = 1
    b = j
    j_count = 0
    while x == 1:
        if j % 3 != 0:
            j -= 1
            j_count += 1
        if j % 3 == 0:
            x = 0
    x = 1
    z = i
    i_count = 0
    while x == 1:
        if i % 3 != 0:
            i -= 1
            i_count += 1
        if i % 3 == 0:
            x = 0

    indices = []
    cnt = 0
    for k in range(0,3):
        indices.append((i+cnt, j))
        i += cnt
        cnt = 1
        for n in range(1,3):
            indices.append((i, j+n))
    return indices






def is_in_square_from_indices(sudoku, indices):
    square_nums = []
    for i in indices:
        square_nums.append(sudoku[i[0]][i[1]])

    l = [0,1,2,3,4,5,6,7,8,9]

    num_list = [i for i in l if i not in square_nums]

    bool_list = []

    for i in range(0,10):
        bool_list.append(i not in num_list)


    return bool_list
    # bool_list = []
    # for i in range(0,10):

def next_entries(sudoku, i, j):
    row = is_in_row(sudoku, i)
    col = is_in_column(sudoku,j)
    sq = is_in_square(sudoku, i, j)

    l = []

    for i in range(0,10):
        if row[i] == False and sq[i] == False and col[i] == False:
            l.append(i)
    return l


def is_in_square(sudoku, i, j):
    return is_in_square_from_indices(sudoku, square_indices(i, j))

def find_all_next_entries(sudoku):
    counter = 0
    for item in sudoku:
        for i in item:
            if i == 0:
                print(next_entries(sudoku, sudoku.index(item), item.index(i)))

                # loc = item.index(0,counter)
                # # print(loc)
                # # print(item)
                # cnt = 0
                # cnt2=0
                # print(next_entries(sudoku, loc,loc))
                # counter += 1
                # print(item)
                # # for k in range(len(item)):
                # #     cnt +=1
                # #     for c in range(len(item)):
                # #         print(next_entries(sudoku, k, c))


if __name__ == '__main__':
    sudoku = [[0, 5, 1, 2, 0, 0, 0, 9, 0],
              [0, 3, 8, 0, 7, 9, 0, 4, 0],
              [2, 9, 0, 5, 0, 0, 0, 0, 6],
              [1, 2, 3, 6, 0, 0, 7, 0, 0],
              [8, 7, 0, 3, 0, 1, 0, 5, 4],
              [0, 0, 9, 0, 0, 8, 3, 6, 1],
              [4, 0, 0, 0, 0, 2, 0, 1, 5],
              [0, 1, 0, 8, 6, 0, 4, 3, 0],
              [0, 6, 0, 0, 0, 7, 9, 2, 0]]
    print(find_all_next_entries(sudoku))