I have the following dataframe:-

```
traffic_type    date        unique_visitors         region   total_views
desktop         01/04/2018  72                      aug      50
mobileweb       01/04/2018  1                       aug      60
total           01/04/2018  sum(mobileweb+desktop)  aug      100
desktop         01/04/2018  75848907.6              world    20
mobileweb       01/04/2018  105737747.4             world    30
total           01/04/2018  sum(mobileweb+desktop)  world    40

```

This might be a duplicate so any link to similar questions will also help and i can 
build the script on similar lines.
As you can see the data i need to fill in the column of unique\_visitors is sum of desktop and mobile
provided they are in same region and same date. Dataframe i need

```
traffic_type    date        unique_visitors region  total_views
desktop         01/04/2018  72              aug     50
mobileweb       01/04/2018  1               aug     60
total           01/04/2018  73              aug     100
desktop         01/04/2018  75848907.6      world   20
mobileweb       01/04/2018  105737747.4     world   30
total           01/04/2018  181,586,655     world   40

```

Again I am sorry if this is duplicated i am looking reference links if not the exact solution.