def drop_dup_rows(data, print_fn=print):
    """ Drop duplicate rows. """
    print_fn('\nDrop duplicates ...')
    cnt0 = data.shape[0]; print_fn('Samples: {}'.format( cnt0 ))
    data = data.drop_duplicates().reset_index(drop=True)
    cnt1 = data.shape[0]; print_fn('Samples: {}'.format( cnt1 ));
    print_fn('Dropped duplicates: {}'.format( cnt0-cnt1 ))
    return data