Have a df like that:

```
  Client  Status Dat_Start   Dat_End
   1       A     2015-01-01  2015-01-19 
   1       B     2016-01-01  2016-02-02
   1       A     2015-02-12  2015-02-20
   1       B     2016-01-30  2016-03-01

```

I'd like to get average between two dates (Dat\_end and Dat\_Start) for Status='A' grouping by client column using Pandas syntax. 

So it will be smth SQL-like: 

```
Select Client, AVG (Dat_end-Dat_Start) as Date_Diff 
from Table
where Status='A'
Group by Client

```

Thanks!