json listをNewline Delimited JSONに変換する

csv2json.py

import csv
from io import StringIO
import json



if __name__ == '__main__':
  """
  sample1) cat data_with_header.csv | python csv2json.py > test.json
  """
  csv_str = open(0).read()

  data =  csv.DictReader(StringIO(csv_str))
  print(json.dumps([ d for d in data], indent=2))

json2ndjson.py

import json
import sys
import argparse

if __name__ == '__main__':
  """
  sample1) cat test.json | python json2ndjson.py > test.ndjson
  sample2) cat test.json | python json2ndjson.py --key nodes > nodes.ndjson
  """
  json_str = open(0).read()
  json_obj = json.loads(json_str)
  parser = argparse.ArgumentParser()
  parser.add_argument("--key")
  args = parser.parse_args()
  if (args.key):
    json_obj = json_obj[args.key]
  if (isinstance(json_obj, list)):
    for j in json_obj:
      print(json.dumps(j))
  else:
    sys.stderr.write('Not list json')