How can I find the location of the unique item of more than two lists?

Question

How can I find the location of the unique item of more than two lists?

For example:
A=[2,3,4,5,6]
B=[2,4,5,6,8]
C=[3,2]

Return B[4]

(I am actually making a sudoku solver, and want to use this to locate items)

Answer 1

add all lists of block9 into addlist.
res =list( filter(lambda x: addlist. count(x) ==1,addlist)
now find the right list.

for l in block 9:
if res[0] in block9...

Answer 2

https://code.sololearn.com/cFXMlUz77rW3/?ref=app

Answer 3

you can always merge the array first

Answer 4

Thanks Jay,
I am not sure if that's going to work.
you know, I numbered the sudoku into 81 cells, and made functions to get all the data out of these cells, and row numbers, column numbers, block numbers and overlapping cells.
So now I am struggling to go to the next level, filtering out the "hidden singles"
(maybe later I want to trace the "naked sets" and "hidden sets" not sure if this is possible for me)
But for now I want an easy way to get the singles out of 9 lists (or sets), and get the cell number and location:

block: 6
34 ['2', '3', '4', '6', '8']
35 ['1', '2', '3', '4', '6']
36 []
43 ['2', '4', '6', '8', '9']
44 ['2', '4', '6', '9']
45 []
52 ['2', '3', '4', '9']
53 ['1', '2', '3', '4', '9']
54 ['1', '2', '3', '9']

block: 7
55 []
56 []
57 []
64 ['6']
65 []
66 []
73 []
74 ['6', '8']
75 ['8', '9']

block: 8
58 ['6', '7', '9']
59 ['6', '7', '9']
60 ['1', '6', '7']
67 ['2', '3', '4', '6', '8', '9']
68 []
69 ['2', '4', '6']
76 ['2', '3', '4', '6', '7', '8', '9']
77 ['2', '4', '6', '7', '8', '9']
78 ['2', '4', '6', '7']

block: 9
61 ['5', '6', '9']
62 []
63 ['6', '9']
70 ['2', '3', '4', '6', '9']
71 ['2', '3', '4', '6', '9']
72 ['2', '3', '6', '9']
79 []
80 ['2', '3', '4', '6', '7', '9']
81 ['2', '3', '6', '9']

so, I want to get:
60 --> '1'
61 --> '5'
75 --> '9'
80 --> '7'

or

60 --> [0]
61 --> [0]
75 --> [1]
80 --> [4]

Answer 5

Thanks Oma.
But I can't get it working.
is this what you mean:

addlist=[['5', '6', '9'],[],['6', '9'],['2', '3', '4', '6', '9'],['2', '3', '4', '6', '9'],['2', '3', '6', '9'],[],['2', '3', '4', '6', '7', '9'],['2', '3', '6', '9']]
res =list( filter(lambda x: addlist.count(x) ==1,addlist))

Answer 6

Wow, Oma!
Thanks that's perfect.
With this I can finish my Sudoku project.
Thanks you very much