content: import datetime
  import json
  import logging
  
  class JSONFormatter(logging.Formatter):
      """
      Render logs as JSON.
  
      To add details to a log record, store them in a ``event_data``
      custom attribute. This dict is merged into the event.
  
      """
      def __init__(self):
          pass  # override logging.Formatter constructor
  
      def format(self, record):
          event = {
              "timestamp": self.getTimestamp(record.created),
              "message": record.getMessage(),
              "level": record.levelname,
              "logger": record.name,
          }
          event_data = getattr(record, "event_data", None)
          if event_data:
              event.update(event_data)
          if record.exc_info:
              event["exc_info"] = self.formatException(record.exc_info)
          if record.stack_info:
              event["stack_info"] = self.formatStack(record.stack_info)
          return json.dumps(event)
  
      def getTimestamp(self, created):
          return datetime.datetime.utcfromtimestamp(created).isoformat()
  