creating a new list with subset of list using index in python

Question

A list:

a = [\'a\', \'b\', \'c\', 3, 4, \'d\', 6, 7, 8]

I want a list using a subset of a using a[0:2],a[4], a[6:],

t

Answer 1

The following definition might be more efficient than the first solution proposed

def new_list_from_intervals(original_list, *intervals):
    n = sum(j - i for i, j in intervals)
    new_list = [None] * n
    index = 0
    for i, j in intervals :
        for k in range(i, j) :
            new_list[index] = original_list[k]
            index += 1

    return new_list

then you can use it like below

new_list = new_list_from_intervals(original_list, (0,2), (4,5), (6, len(original_list)))