code: def open_cards(filename=None):
      
      filename = filename or "cards-%s.txt" % (time.strftime("%Y%m%d"))
  
      with open(filename, "r") as deck_file:
          card_data = [line.rstrip("\n") for line in deck_file.readlines()]
  
      cards = [None] * len(card_data)
  
      for i, card in enumerate(card_data):
          card = card.split()
          cards[i] = Card(card[0], card[1])
  
      return cards
docs: Open cards from a txt file.
  
      :arg str filename:
          The filename of the deck file to open. If no filename given,
          defaults to "cards-YYYYMMDD.txt", where "YYYYMMDD" is the year, month,
          and day. For example, "cards-20140711.txt".
  
      :returns:
          The opened cards, as a list.