remove char in string at many specific index when index are in the list

Question

I want to remove character from string seq_in = 'KPKPAJDSKGRPRRKAPPP' at specific indices in the list ind = [0, 1, 2, 3, 8, 10, 11, 12, 13, 14, 16, 17, 18] . The result should be 'AJDSGA' . I tried remove() the string by looping the ind list, but each character's index was shifted.

How to remove many characters at index from the list without loop?

Answer 1

You can use a generator expression within join using enumerate to get the index of each letter. If the index isn't in ind then keep it.

>>> ''.join(j for i,j in enumerate(seq_in) if i not in ind)
'AJDSGA'

As mentioned in the comments, your lookups will be faster if ind is a set than if it stays a list

>>> ind = {0, 1, 2, 3, 8, 10, 11, 12, 13, 14, 16, 17, 18}
>>> ''.join(j for i,j in enumerate(seq_in) if i not in ind)
'AJDSGA'