e jointly unique), the rest are unique.

         A      B  C         D         E  (tuple, as, label)
    0  foo    one  a  0.608477 -0.012500           -1.664297
    1  foo    two  b -0.633460  0.249614           -0.364411
    2  foo  three  c  0.615256  2.154968           -0.834666
    3  bar    one  d  0.234246  1.085675            0.718445
    4  bar    two  e  0.533841 -0.005702           -3.533912
    )