code: def rpop(self, key):
          
          redis_list = self._get_list(key, 'RPOP')
  
          if self._encode(key) not in self.redis:
              return None
  
          try:
              value = redis_list.pop()
              if len(redis_list) == 0:
                  self.delete(key)
              return value
          except (IndexError):
              # Redis returns nil if popping from an empty list
              return None
docs: Emulate lpop.