def?getSubjectStats(subject,?weights): ????''' ???????e.g. ???????subject:[['Bart','geology'],[10,5,85]]--grades即是[10,5,85] ???????weights:[0.3,0.2,0.5] ????''' ????return?[[elt[0],?elt[1],?avg(elt[1],?weights)] ????????????for?elt?in?subject] ???????????? def?dotProduct(a,b): ????result?=?0.0 ????for?i?in?range(len(a)): ????????result?+=?a[i]*b[i] ????return?result???? ???? def?avg(grades,?weights): ????try: ????????return?dotProduct(grades,?weights)/len(grades)#這幾個(gè)函數(shù)就是為了求同學(xué)加權(quán)平均成績(jī)，但是這里是不是錯(cuò)了？/len(grades)這個(gè)地方不對(duì)吧？加權(quán)平均數(shù)比如Bart地理成績(jī)是[10,5,85],三個(gè)各占比例[0.3,0.2,0.5]，那么應(yīng)該是（10*0.3）+（5*0.2）+（85*0.5）就可以了啊，就算再除以那也是除以%100才對(duì)，怎么能再除以3？？大神能否解答一下！ ????except?ZeroDivisionError: ????????print?'no?grades?data' ????????return?0.0