CSV to JSON conversion (in Python)

csv2json.py

import csv
import json

csvfile = open('DE.txt', 'r')
jsonfile = open('de.json', 'w')

fieldnames = ("countryCode","postalCode","placeName","adminName1","adminCode1","adminName2","adminCode2","adminName3","adminCode3","latitude","longitude","accuracy")
reader = csv.DictReader(csvfile, fieldnames, delimiter='\t')
jsonfile.write("{ \"docs\": [")

for row in reader:
    lat = row["latitude"]
    lon = row["longitude"]
    row.pop("latitude")
    row.pop("longitude")
    row["loc"] = [float(lon), float(lat)]
    json.dump(row, jsonfile)
    jsonfile.write(",\n")

jsonfile.write("]}")