String slicing by index list

Question

I have a list of lengths present in a list, like:

a = [1, 3, 4]

Moreover, I have string who's length is exactly the sum of the numbers of a, here 8, looking like that:

s = "01100110"

I am looping over length of a and every time, I would like to have exactly the next n bits present in a. So here, it would be three runs, giving me "0", "110" and "0110".

Is there a very clever idea to do that efficient, for example by slicing? I have some weird complicated ways in my head but search for something more efficient.

Some solution I came up with:

counter_index = 0
counter_sum = 0

for i in range(len(a)):
   res = s[counter_sum:counter_sum+a[counter_index]
   counter_sum += a[counter_index]
   counter_index += 1
   print(res)

Answer 1

This approach basically updates the string each time it is sliced so we can get the next value by simply using the values in a as the index value directly instead of adding it to the existing position value.

a = [1, 3, 4]
s = "01100110"
st = s
i = 0
while i < len(a):
    print(st[:a[i]])
    st = st[a[i]:]
    i+=1
 

Output

0
110
0110

Answer 2

something like the below is the "slicing" solution to go with

a = [1, 3, 4]
s = "01100110"
offset = 0
for x in a:
    print(f'{s[offset: offset+x]}')
    offset += x

output

0
110
0110