To get assembly_constituency,parliamentary_constituency as a listing of parliamentary_constituency with its assembly_constituencies below it, we can use VIM macro which does the job in a matter of seconds.
i.e
Gummidipoondi (AC-1),Thiruvallur (PC-1)
Ponneri (AC-2),Thiruvallur (PC-1)
Thiruvallur (AC-4),Thiruvallur (PC-1)
Poonamallee (AC-5),Thiruvallur (PC-1)