old_contents: 
  import logging
  
  FORMAT = '[%(asctime)s] %(levelname)5s -- : %(message)s'
  DATE_FORMAT = '%Y-%m-%dT%H:%M:%S'
  
  class PicklableHandler(logging.Handler):
      def __init__(self):
          super(PicklableHandler, self).__init__()
          self.setFormatter(logging.Formatter(FORMAT, DATE_FORMAT))
          self.__log_list = []
  
      def createLock(self):
          self.lock = None
  
      def emit(self, record):
          self.__log_list.append(record)
          print(self.format(record))
  
      def print_all_logs(self):
          for record in self.__log_list:
              print(self.format(record))
  
new_contents: 
  import logging
  
  FORMAT = '[%(asctime)s] %(levelname)5s -- : %(message)s'
  DATE_FORMAT = '%Y-%m-%dT%H:%M:%S'
  
  class PicklableHandler(logging.Handler):
      def __init__(self, fmt=FORMAT, date_format=DATE_FORMAT):
          super(PicklableHandler, self).__init__()
          self.setFormatter(logging.Formatter(fmt, date_format))
          self.__log_list = []
  
      def createLock(self):
          self.lock = None
  
      def emit(self, record):
          self.__log_list.append(record)
          print(self.format(record))
  
      def print_all_logs(self):
          for record in self.__log_list:
              print(self.format(record))
  
subject: Set default log format.