old_contents: import os
  from datetime import datetime
  from time import time
  
  
  class Result:
      def __init__(self, directory):
          date = datetime.fromtimestamp(time())
          name = '%d-%d-%d_%d-%d-%d' % (
              date.year,
              date.month,
              date.day,
              date.hour,
              date.minute,
              date.second)
          self.file = File(directory, name)
  
  
  class File:
      def __init__(self, directory, name):
          if not os.path.exists(directory):
              os.makedirs(directory)
          self.path = os.path.join(directory, name)
          if not os.path.exists(self.path):
              open(self.path, 'w').close()
  
      def write_line(self, text):
          stream = open(self.path, 'a')
          stream.write('%s\n' % text)
          stream.close()
  
new_contents: import os
  from datetime import datetime
  from time import time
  
  
  class Result:
      def __init__(self, directory):
          date = datetime.fromtimestamp(time())
          self.file = File(directory, date.strftime('%Y-%m-%d_%H-%M-%S'))
  
  
  class File:
      def __init__(self, directory, name):
          if not os.path.exists(directory):
              os.makedirs(directory)
          self.path = os.path.join(directory, name)
          if not os.path.exists(self.path):
              open(self.path, 'w').close()
  
      def write_line(self, text):
          stream = open(self.path, 'a')
          stream.write('%s\n' % text)
          stream.close()
  
subject: Use date-format function for file-name