('CID100117642', 2),Heptanoicacid, 2,2-bis[[(1-oxoheptyl)oxy]methyl]-1,3-propanediyl ester (9CI)
('CID100117642', 2), Heptanoicacid, neopentanetetrayl ester (8CI)
('CID105282683', 2),Heptanoicacid, 3-methyl-, (R)-
('CID105282683', 2),Heptanoicacid, 3-methyl-, (S)-
ldiff: defaultdict(<type 'list'>, {'CID105282683': [17, 17], 'CID100117642': [63, 32]})
f1: [63, 32]
f2: [17, 17]
c1: Counter({32: 1, 63: 1})
c2: Counter({17: 2})
The chosen was  ... CID105282683