I have a dataframe like this:
A      B      C      D      E ...
a1     b1     c1     d1     e1 ...
a2     b2     c2     d2     e2 ...
I want to change to:
A      B      Name  Value
a1     b1     D     d1 
a1     b1     E     e1
...
a2     b2     D     d2
a2     b2     E     e2
Is it possible to do with pandas? (Column A & B is the unique union column, column C is the one we don't need any more)
