浅谈Python数据处理csv的应用小结

fr=open("scores.csv","r")
fw=open("data.csv","w")
ls=[]
for line in fr:
    line=line.replace("\n","")
    ls.append(line.split(","))
ChMax=[0,'']
ChMin=[100,'']
MaMax=[0,'']
MaMin=[100,'']
EnMax=[0,'']
EnMin=[100,'']

#当函数有list或者 dictionary 作为形参时,会改变其实参的值(在函数中若改动其值）
#但是若不想实参的值收到影响,在传参的时候可以使用[].copy方法。list和dictionary都有copy方法。
# def updateMaxMin(Max,Min,score,i):
#     if(score>Max[0]):
#         Max=[0,'']
#         Max[0]=score
#         Max[1]=ls[i][0]
#     elif(score==Max[0]):
#         Max.append(ls[i][0])
#     if(score<Min[0]):
#         Min=[100,'']
#         Min[0]=score
#         Min[1]=ls[i][0]
#     elif(score==Min[0]):
#         Min.append(ls[i][0])

for i in range(1,len(ls)):
    sum=eval(ls[i][1])+eval(ls[i][2])+eval(ls[i][3])
    #将总分列添加到二维列表中
    ls[i].append(sum)

    # updateMaxMin(Max=ChMax,Min=ChMin,score=eval(ls[i][1]),i=i)
    # updateMaxMin(Max=MaMax,Min=MaMin,score=eval(ls[i][2]),i=i)
    # updateMaxMin(Max=EnMax,Min=EnMin,score=eval(ls[i][3]),i=i)

    #语文最高分最低分更新
    chScore=eval(ls[i][1])
    if (chScore > ChMax[0]):
        ChMax = [0, '']
        ChMax[0] = chScore
        ChMax[1] = ls[i][0]
    elif (chScore == ChMax[0]):
        ChMax.append(ls[i][0])
    if (chScore < ChMin[0]):
        ChMin = [100, '']
        ChMin[0] = chScore
        ChMin[1] = ls[i][0]
    elif (chScore == ChMin[0]):
        ChMin.append(ls[i][0])

    #数学最高分最低分更新
    maScore=eval(ls[i][2])
    if (maScore > MaMax[0]):
        MaMax = [0, '']
        MaMax[0] = maScore
        MaMax[1] = ls[i][0]
    elif (maScore == MaMax[0]):
        MaMax.append(ls[i][0])
    if (maScore < MaMin[0]):
        MaMin = [100, '']
        MaMin[0] = maScore
        MaMin[1] = ls[i][0]
    elif (maScore == MaMin[0]):
        MaMin.append(ls[i][0])

    #英语最高分最低分更新
    enScore=eval(ls[i][3])
    if (enScore > EnMax[0]):
        EnMax = [0, '']
        EnMax[0] = enScore
        EnMax[1] = ls[i][0]
    elif (enScore == EnMax[0]):
        EnMax.append(ls[i][0])
    if (enScore < EnMin[0]):
        EnMin = [100, '']
        EnMin[0] = enScore
        EnMin[1] = ls[i][0]
    elif (enScore == EnMin[0]):
        EnMin.append(ls[i][0])

#将二维列表中每一行按照总分从大到小排序
#这里我用的是冒泡排序
for i in range(1,len(ls)):
    for j in range(i+1,len(ls)):
        if ls[i][4]<ls[j][4]:
            ls[i],ls[j]=ls[j],ls[i]

#将名次列添加到二维列表中
ls[1].append(1)
count=2
for i in range(2,len(ls)):
    if ls[i][4]==ls[i-1][4]:
        ls[i].append(ls[i-1][5])
    else:
        ls[i].append(count)
    count+=1

print("语文:{0},{1}".format(tuple(ChMax),tuple(ChMin)))
print("数学:{},{}".format(tuple(MaMax),tuple(MaMin)))
print("英语:{},{}".format(tuple(EnMax),tuple(EnMin)))

#将表中数据全部转换成字符串
for i in range(len(ls)):
      for j in range(len(ls[i])):
          ls[i][j]=str(ls[i][j])

#扩充表头
ls[0].append("总分")
ls[0].append("名次")

#写入data.csv
for row in ls:
      fw.write(",".join(row)+"\n")
fr.close()
fw.close()