I have listA=[[0,1],[1,2]], and listB=[[0,1,2],[0,1,3],[0,2,3],[0,2,4]].
I want to find all elements b from listB such that b⊆a doesn’t hold and a⊆b doesn’t hold for all elements a from listA. Put it another way, my desired output is: listC=[[0,2,3],[0,2,4]].
I tried the following codes:
import numpy as np
listA=[[0,1],[1,2]]
listB=[[0,1,2],[0,1,3],[0,2,3],[0,2,4]]
listC=[b for b in listB if (((not set(a).issubset(set(b))) and (not set(b).issubset(set(a)))) for a in listA)]
print(listC)
However, the output is [[0,1,2],[0,1,3],[0,2,3],[0,2,4]], which is not what I want. My guess is that something is wrong in the if part of the list comprehension. How could it be fixed? Thanks.
>Solution :
Your condition is a little wonky. You want the elements in listB that are not superset (or subset) of any element in listA. So if you replace
(((not set(a).issubset(set(b))) and (not set(b).issubset(set(a)))) for a in listA)
with
any(set(a).issubset(b) or set(b).issubset(a) for a in listA)
it will work as expected.
listC = [b for b in listB if not any(set(a).issubset(b) or set(b).issubset(a) for a in listA)]
Output:
[[0, 2, 3], [0, 2, 4]]