checkgraph.py

friendset = set()

for line in open('input/soc-LiveJournal1Adj.txt'):
    try:
        user, friends = line.strip().split('\t')
    except ValueError:
        continue
    for friend in friends.split(','):
        friendset.add((user, friend))

for f1, f2 in friendset:
    if (f2, f1) not in friendset:
        print repr(f2), repr(f1)