old_contents: """
  Created on Dec 04, 2016
  
  @author: john papa
  
  Copyright 2016 John Papa.  All rights reserved.
  This work is licensed under the MIT License.
  """
  from abc import ABCMeta, abstractproperty
  
  class Card(metaclass=ABCMeta):
  
      def __init__(self, suit, rank):
          self._rank = rank
          self._suit = suit
          self._value = None
  
      def __str__(self):
          return f"{self._rank} of {self._suit}"
  
      @property
      def rank(self):
          return self._rank
  
      @property
      def suit(self):
          return self._suit
  
      @abstractproperty
      def value(self):
          """ Returns the value of the card used for scoring the game """
  
new_contents: """
  Created on Dec 04, 2016
  
  @author: john papa
  
  Copyright 2016 John Papa.  All rights reserved.
  This work is licensed under the MIT License.
  """
  from abc import ABCMeta, abstractproperty
  
  class Card(metaclass=ABCMeta):
  
      def __init__(self, suit, rank):
          self._rank = rank
          self._suit = suit
          self._value = None
  
      def __str__(self):
          # return f"{self.rank} of {self.suit}"
          return "{0} of {1}".format(self.rank, self.suit)
  
      @property
      def rank(self):
          return self._rank
  
      @property
      def suit(self):
          return self._suit
  
      @abstractproperty
      def value(self):
          """ Returns the value of the card used for scoring the game """
  
subject: Switch to pre-python 3.6 string formatting for Codeship