Looping through dictionary and comparing values with elements of a separate list.

[buran]

Hmm, this doesn't take into account the instances where the 2 elements being compared are the same.

let's take the check in a function

import csv

def check_line(line, isolate):
    my_set = set(line)
    return len(my_set & isolate) == len(my_set)

with open('isolate_file.txt') as f:
    new_isolate = {line.strip() for line in f}

with open('snapper_data.csv') as sd:
    rdr = csv.reader(sd)
    my_isolates = [line[1:] for line in rdr if check_line(line[1:-1], new_isolate)]
             
print(my_isolates)

you can do it also like this

import csv

with open('isolate_file.txt') as f:
    new_isolate = {line.strip() for line in f}

with open('snapper_data.csv') as sd:
    rdr = csv.reader(sd)
    my_isolates = [line[1:] for line in rdr if line[1] in new_isolate and line[2] in new_isolate]
             
print(my_isolates)