Python manipulation of csv

fix-relations.py

import gzip, csv, json, sys
csv.field_size_limit(sys.maxsize)

fi = csv.reader(gzip.open("/home/postgres/relations.csv.gz","rb"))
fiout2 = gzip.open("fixedrelations.csv.gz","wb")
fiout = csv.writer(fiout2)
for li in fi:
	oldmems = json.loads(li[-1])
	assert(len(li)==10)
	mems=[]
	roles = []
	for m in oldmems:
		mems.append([m[0], m[1]])
		roles.append(m[2])

	li[-1] = json.dumps(mems)
	li.append(json.dumps(roles))
	fiout.writerow(li)

fiout2.close()