从最高到最低排序数据，并从文本文件中按Python从最高到最低排序平均值

I need to create a program that you type in which class you want and what you want it sorted in (alphabetically, averages and highest to lowest) and it prints it when run. This is my code so far I have managed to do the alphabetical part but am struggling on the average and the highest to lowest part.I need to create a program that you type in whi