JSON to CSV conversion benchmarking

benchmark.txt

json2csv.py
real	5m28.824s
user	5m27.584s
sys	0m1.524s

C (https://github.com/jehiah/json2csv)
real	0m15.945s
user	0m15.181s
sys	0m1.204s

json2csv.py

import json
import csv
import sys

fields = sys.argv[1].split(",")
output = csv.writer(sys.stdout, delimiter=',', quotechar='"')

for line in sys.stdin:
    if line.strip() != "":
        try:
            obj = json.loads(line)
            row = []
            for field in fields:
                if field in obj:
                    row.append(obj[field])
                else:
                    row.append(None)
            output.writerow(row)
        except ValueError:
            sys.stderr.write("Error: %s" % line)