CODEWITHSUNDEEP
pythonlistdictionarylist-comprehension
Carlos Eduardo Corpus
Carlos Eduardo Corpus

Reputation: 349

Counting the number of occurrences and compare to another list

I'm working with 4D list counting the numbers of occurrences and then compare to a 3D list that I use for reference , I was able to do it, but I'm having problem during the comparison, this is my code:

from collections import Counter

reference = [[[2, 3], [2, 4], [3, 2], [4, 2]], 
             [[2, 3], [3, 2], [3, 4], [4, 3]], 
             [[2, 3], [3, 2], [3, 4], [4, 3]]]

#This is my 4D list
coord = [[[[4, 2], [2, 3]], [[4, 3], [4, 3]], [[3, 2], [2, 3], [3, 4]]], [[[4, 2], [2, 3]], [[4, 3], [4, 3]], [[3, 2], [2, 3], [3, 4]]]]

#To count the numbers of occurrences
occurrences = [[Counter(tuple(j) for j in i) for i in k] for k in coord]

print(occurrences)

ocurrences = [[Counter({(4, 2): 1, (2, 3): 1}), Counter({(4, 3): 2}), Counter({(3, 2): 1, (2, 3): 1, (3, 4): 1})], [Counter({(4, 2): 1, (2, 3): 1}), Counter({(4, 3): 2}), Counter({(3, 2): 1, (2, 3): 1, (3, 4): 1})]]

So far so good, It creates a list of list of Counter out of the 4D list, the first 3 Counter correspond to the first 3D list in the 4D list, and the next 3 Counter for the other 3D list. Now I need to compare the first list of occurrences with the reference list and then the second list of occurrences with the same references list. This is what I did:

out = [[[k[tuple(j)] for j in i] for k in cntr] for i,cntr in zip(reference,occurrences)]

print(out)

out = [[[1, 0, 0, 1], [0, 0, 0, 0], [1, 0, 1, 0]], [[1, 0, 0, 0], [0, 0, 0, 2], [1, 1, 1, 0]]]

For example the first Counter is (4, 2): 1, (2, 3):1 if I compare the matching keys to the first list of reference ie [[2, 3], [2, 4], [3, 2], [4, 2]] I should get [1, 0, 0, 1] which is indeed what I get, but the second Counter is (4, 3): 2 and if I compare two the second list of reference I should get [0, 0, 0, 2] but I'm getting [0, 0, 0, 0] which is wrong. This is my desired output:

output = [[[1, 0, 0, 1], [0, 0, 0, 2], [1, 1, 1, 0]], [[1, 0, 0, 1], [0, 0, 0, 2], [1, 1, 1, 0]]]

This is just an example just to simplify, I think it has to do something with the loop, but I'm not sure what is the problem, so any idea would be great, thank you!

Upvotes: 0

Views: 110

Answers (1)

Prem Anand
Prem Anand

Reputation: 2537

Navigate through each of the list of Counters in ocurrences and then get the frequency of each element in reference (as a tuple) from the corresponding counter

>>> [[[occ[i][tuple(r)] for r in ref] for i,ref in enumerate(reference)] for occ in ocurrences]
[[[1, 0, 0, 1], [0, 0, 0, 2], [1, 1, 1, 0]], [[1, 0, 0, 1], [0, 0, 0, 2], [1, 1, 1, 0]]]

Upvotes: 2

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