How to remove elements from multiple sublists according to another sublist in Python

Question

I have a list J and removing elements from J according to index. I am trying to remove elements of J[0]=[2, 6, 9, 10] according to index[0]=[0,3]. Now after removing, I have J=[6,9] which should append to create [[2, 6, 9, 10], [6, 9]]. Now it should take [6,9] and remove element according to index[1]=[1]. I present the current and expected outputs.

J=[[2, 6, 9, 10]]

index=[[0,3],[1]]

u=0

for v in range(0,len(index)): 
    new_J = [j for i, j in enumerate(J[u]) if i not in index[v]]
    J.append(new_J)

print(J)

The current output is

[[2, 6, 9, 10], [6, 9], [2, 9, 10]]

The expected output is

[[2, 6, 9, 10], [6, 9], [6]]

Asked By: isaacmodi123

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Source

Answer 1

Just take your example, try this:

J=[[2, 6, 9, 10]]

index=[[0,3],[1]]

u=0

for v in range(0,len(index)): 
    new_J = [j for i, j in enumerate(J[-1]) if i not in index[v]]
    J.append(new_J)

print(J)

Answered By: gepcel

Answer 2

You can apply itertools.accumulate:

from itertools import accumulate

J = [[2, 6, 9, 10]]
idx = [[0,3], [1]]
J = list(accumulate(idx, lambda lst, idx: [v for i, v in enumerate(lst) if i not in idx],
                    initial=J[-1]))

[[2, 6, 9, 10], [6, 9], [6]]

Answered By: RomanPerekhrest

How to remove elements from multiple sublists according to another sublist in Python

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