lst1 = [('vr1', '635', '1'), ('vr1', '32', '1'), ('vr1', '784', '0.526'), (
    'vr1', '431', '1')] * 10000
lst2 = [('vr1', '635', '3'), ('vr1', '784', '2.526'), ('vr1', '431', '2')
    ] * 10000
Obtain unique entries in column specific list comparison, efficiently