duplicates removal on the fly

gistfile1.txt

from collections import defaultdict

your_dict = {}
lookup_table = defaultdict(list)

for line in file_handle:

    acc, fields = get_fields(line)

    for i in fields:
    # Dunno if this happens at all
        if acc in lookup_table[i]:
            lookup_table[i].append(acc)
       
    your_dict[acc] = [x for x in fields if x not in lookup_table[acc]]