Still new into pandas but is there a way to sort df by subtotal of each group.
 Area   Unit   Count
  A     A1      5
  A     A2      2
  B     B1      10
  B     B2      1 
  B     B3      3
  C     C1      10
So I want to sort them by subtotal of each Area which results to A subtotal = 7, B subtotal=14, C subtotal = 10
The sort should be like
 Area   Unit   Count
  B     B1      10
  B     B2      1 
  B     B3      3
  C     C1      10
  A     A1      5
  A     A2      2
*Note that despite the value of B3 > B1 it should not be affected by the sort. 
 
    