niveum/packages/json2csv.nix

# Convert JSON array of objects to CSV
{
  writers,
  python3,
}:
writers.writePython3Bin "json2csv" {
  flakeIgnore = [ "E501" ];
} ''
  import csv
  import json
  import sys

  if __name__ == "__main__":
      json_list = json.load(sys.stdin)
      if not isinstance(json_list, list):
          print("JSON object is not a list.", file=sys.stderr)
          sys.exit(1)
      if len(json_list) == 0:
          print("JSON list is empty.", file=sys.stderr)
          sys.exit(1)
      keys = set()
      for element in json_list:
          if isinstance(element, dict):
              keys |= element.keys()
          else:
              print("Non-dict element:", element, file=sys.stderr)
              sys.exit(1)
      writer = csv.DictWriter(sys.stdout, fieldnames=list(keys))
      writer.writeheader()
      for element in json_list:
          writer.writerow(element)
''