Remove item from list based on the next item in same list

Question

I just started learning python and here I have a sorted list of protein sequences (total 59,000 sequences) and some of them overlap. I have made a toy list here for example:

Answer 1

A simple way is to process the input file one line at a time, compare each line with the previous one and keep previous one if it is not contained in current one.

Code can be as simple as:

with open('toy.txt' ,'r') as f:
    old = next(f).strip()               # keep first line after stripping EOL 

    for pattern in f:
        pattern = pattern.strip()       # strip end of line...
        if old not in pattern:
            print old                   # keep old if it is not contained in current line
        old = pattern                   # and store current line for next iteration
    print old                           # do not forget last line