找到一份通过的代码，你们看看

#!/usr/bin/env python
import math
import random
import sys
class Solution2(object):
    def tfidf(self, line, idf):
        tf = {}
        tfidf = []
        data = []
        words = line.split(",")
        length = len(words)
        for word in words:
            tf[word] = tf.get(word, 0) + 1 / length
        for word in words:
            tfidf.append(str(round(tf.get(word) * idf.get(word), 2)))
            data.append("tf:%s,idf:%s" % (tf.get(word), idf.get(word)))
        return (tfidf)
    def getWordDocs(self, docs):
        N = len(docs)
        idf = {}
        for doc in docs:
            words = set(doc.split(","))
            for word in words:
                idf[word] = idf.get(word, 0) + 1
        for (k, v) in idf.items():
            idf[k] = round(math.log(N / v, 2), 2)
        return idf
if __name__ == "__main__":
    solution2 = Solution2()
    n = int(sys.stdin.readline().strip())
    dd = []
    for i in range(0, n):
        dd.append(sys.stdin.readline().strip())
    idf = solution2.getWordDocs(dd)
    for item in dd:
        tfidf = solution2.tfidf(item, idf)
        print(",".join(tfidf))