code: def macro_calc(item):
      
      try:
          item_sum = sum(item.values())
          item_len = len(item.values())
          return item_sum / item_len
      except Exception:
          return "None"
docs: Calculate PPV_Macro and TPR_Macro.
  
      :param item: PPV or TPR
      :type item:dict
      :return: PPV_Macro or TPR_Macro as float