python小问题，词频统计，统计次数。

Question

统计csv文件中出现最多的5个分数值及其出现次数，csv文件中的大于100的分数值、x、空都不用修改。
csv文件我的问答里
文件读写、最后输出可参考如下代码：

with open("python23成绩10-25-2021.csv","r",encoding="utf-8") as f:
    #ls1 = f.readlines()
    str1 = f.read()
#print(ls1[0])
#print(ls1[1].strip("\n"))
#print(ls1[2])
#print(str1)

str3 = str1.replace("\n",",")

###开始补充代码：


###结束补充代码

for i in range(5):
    score,num = list4[i]
    print("{}:{}".format(score,num))

输入 :无输入
输出 :
100.00:x
0.00:y
xxx3:yy1
xx4:yy2
xx5:yy3

赏金=10RMB，五天后删除.

Answer 1

from collections import Counter 

with open(r'python23成绩10-25-2021.csv', encoding='utf-8') as f:
    lineCon = f.readlines()
    lineCon =[i[:len(i)-1] if '\n' in i else i for i in lineCon[1:]]
    lineCon =','.join(map(lambda k: ','.join(k.split(",")[3:]), lineCon))
    lineCon = lineCon.split(",")
    res = dict(Counter(lineCon))
    res = sorted(res.items(), key=lambda x: x[1], reverse= True)
    for i in res[:5]:
        print("{:>6}:{:<3}".format(*i))