Parsing csv files with tab delimiter to JSON

parser.py

import csv
import json

csvfile = open('file1.csv', 'r')
jsonfile = open('file2.json', 'w')

fieldnames = ("firstname", "lastname", "phone", "birthdate")

reader = csv.DictReader( csvfile, fieldnames, delimiter='\t')
for row in reader:
    json.dump(row, jsonfile)    
    jsonfile.write('\n')