with open('data.txt') as f:
    header = f.readline()
with open('result.txt', 'w') as w:
    w.write(header)
for n, line in enumerate(f.readlines()):
    elems = line.split('\t')
e0 = elems[0].split(',')
e0 = [e.replace('"', '').strip() for e in e0]
for pairs in itertools.combinations(e0, 2):
    w.write('{:d}\t{}\t{}\n'.format(n + 1, '\t'.join(pairs), '\t'.join(
        elems[1:])))
how to make a pair combination per each line