How to match two list with the same length

Question

i have two list with the same length. i would like to find a match in df and df2.

   df = [[[1, 5,7,9,12,13,17],
   [2,17,18,23,32,34,45],
   [3,5,11,33,34,36,45]],
  [[6,21,22,50,56,58,72],
  [7,5,12,13,55,56,74],
  [8,23,24,32,56,58,64]]]

    df2 = [[[100,5,12,15,27,32,54],
    [120,10,17,18,19,43,55],
    [99,21,32,33,34,36,54]],
   [[41,16,32,45,66,67,76],
    [56,10,11,43,54,55,56],
    [77,12,16,18,19,21,23]]]
    

i would like my output to be like this or similar.

    output = [[[[5,12,],[17]],
      [[17,18],[32,34,36]]],
      [[[55,56],[32]],[[56]]]

Answer 1

So this problem is difficult because you in order to compare the arrays you need to compute all possible sequences that could occur first. So when you are dealing with large arrays, this tasks will take very long.

My approach is not optimized in any way for simplicity, I tried to stick to basic for loops and just brute forced through it.

At first, I will compute all possible combinations for both arrays and store them in two lists ( sequences_1 and sequences_2 ).

Afterward, I will compare all the sequences and store the matches in a set. Using a set will automatically get rid of all duplicates. Matches now holds all possible matches of the two arrays.

df = [
    [[1, 5, 7, 9, 12, 13, 17], [2, 17, 18, 23, 32, 34, 45], [3, 5, 11, 33, 34, 36, 45]],
    [[6, 21, 22, 50, 56, 58, 72], [7, 5, 12, 13, 55, 56, 74], [8, 23, 24, 32, 56, 58, 64]],
]

df2 = [
    [[100, 5, 12, 15, 27, 32, 54], [120, 10, 17, 18, 19, 43, 55], [99, 21, 32, 33, 34, 36, 54]],
    [[41, 16, 32, 45, 66, 67, 76], [56, 10, 11, 43, 54, 55, 56], [77, 12, 16, 18, 19, 21, 23]],
]

sequences_1 = []

for el in df:
    for lis in el:
        length = len(lis)
        for i in range(0, length):
            for n in range(i + 1, length + 1):
                sequences_1.append(lis[i:n])

sequences_2 = []

for el in df2:
    for lis in el:
        length = len(lis)
        for i in range(0, length):
            for n in range(i + 1, length + 1):
                sequences_2.append(lis[i:n])

matches = set()

for seq_1 in sequences_1:
    for seq_2 in sequences_2:
        if seq_1 == seq_2:
            matches.add(tuple(seq_1))
print(matches)

As matches, I get:

{(5,), (11,), (17,), (23,), (17, 18), (32,), (55, 56), (56,), (5, 12), (34, 36), (34,), (33, 34, 36), (55,), (33, 34), (12,), (18,), (21,), (33,), (36,), (45,)}

This holds all the matches you presented as a possible output, plus additional ones you missed when posting your question.