Slicing lists according to another list

Question

I need to slice list of nucleotide sequences eg. ["ATGCTGACTGCA", "ATGCAGGCGTAG"] according to two other list, one with the start codon and one with the stop codon.

I have all my data in a pandas dataframe, and extracted it into a np array for the sequence and two lists for the start and stop. I've tried with list comprehension:

seq = ["ATGCTGACTGCA", "ATGCAGGCGTAG"]
start = [1, 4]
stop = [6, 12]

[sublist[x:y] for x in start for y in stop for sublist in seq]

I tought this would associate the start and end of the sequence I needed and slice the sequence, but the result is a combination (the new list has 8 entries) What am i doing wrong?

Answer 1

I think you would need one of the following two cases:

A nested loop with a zip, in case you want to get the two sublists for each sequence:

[sublist[x:y] for x,y in zip(start,stop) for sublist in seq]

Having the following result:

['TGCTG', 'TGCAG', 'TGACTGCA', 'AGGCGTAG']

Or just a zip with all:

[sublist[x:y] for x,y,sublist in zip(start,stop,seq)]

Getting the following result:

['TGCTG', 'AGGCGTAG']

Answer 2

I think you want a zip instead of a nested loop.

>>> [s[x:y] for x, y in zip(start, stop) for s in seq]
['TGCTG', 'TGCAG', 'TGACTGCA', 'AGGCGTAG']