def macro_calc(item):
    """
    Calculate PPV_Macro and TPR_Macro.

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