title: Reshape a pandas DataFrame using combination of row values in two columns
body: <p>I have data for multiple customers in data frame as below-</p>
  
  <pre>
  Customer_id     event_type  month   mins_spent
  1               live        CM          10
  1               live        CM1         10
  1               catchup     CM2         20
  1               live        CM2         30
  
  2               live        CM          45
  2               live        CM1         30
  2               catchup     CM2         20
  2               live        CM2         20
  </pre>
  
  <p>I need the result data frame so that there is one row for each customer and column are combined value of column month and event_type and value will be mins_spent. Result data frame as below-</p>
  
  <pre>
  Customer_id     CM_live CM_catchup  CM1_live    CM1_catchup CM2_live    CM2_catchup
  1               10      0           10          0           30              20
  2               45      0           30          0           20              20
  </pre>
  
  <p>Is there an efficient way to do this instead of iterating the input data frame and creating the new data frame ?</p>