idcheck2.py

#!/usr/bin/env python3
import csv
import sys

firstdata = {}
with open(sys.argv[1],"r") as csvfile1:
  reader1=csv.reader(csvfile1,delimiter=" ")
  for line in reader1:
    if line[2] in firstdata:
      firstdata[line[2]] = firstdata[line[2]]+list([line[4]])
    else:
      firstdata[line[2]] = list([line[4]])
with open(sys.argv[2],"r") as csvfile2:
  reader2=csv.reader(csvfile2,delimiter=" ")
  for line in reader2:
    if line[2] in firstdata:
      if not line[4] in firstdata[line[2]]:
        print(line[2],":",line[4],"has changed from",line[2],firstdata[line[2]])