Divide CSV file rows into three groups

I have a CSV file as follows: userid,status,date,admin 123,1,2017-07-17,415 123,0,2017-07-18,415 124,0,2017-07-17,416 124,1,2017-07-18,416 125,1,2017-07-17,415 What I need to do is to divide this CSV file into 3 groups as follows: First group: if multiple rows have same userid and same admin then group them by most recent date and status=0 123,1,2017-07-17,415 123,0,2017-07-18,415 Second group: if multiple rows have same userid and same admin then group them by oldest date and status=1 124,0,2017-07-17,416 124,1,2017-07-18,416 Third group: all the others 125,1,2017-07-17,415 Now, I'm trying to get my head around it using python and a for loop to iterate through rows but I could not get any hints so far.