TF-IDF計算 Python

def ComputeFreq(wordlist, text):    result = []    for word in wordlist:        countword = text.count(word)        texted = nltk.word_tokenize(text)        length = len(texted)        freq = countword/length        temp = {}        temp['word'] = word        temp['freq'] = freq        #print freq        result.append(temp)    return resultdef Computetfidf(wordfreq, corpus):    result = []    for item in wordfreq:        word = item['word']        tf = item['freq']        dlength = len(corpus)        count = 1        for line in corpus:            if line.find(word)!=-1:                count = count+1        idf = math.log10(dlength/count)        tfidf = tf*idf#         tempword.append(word)#         temptfidf.append(tfidf)          temp = {}        temp['word'] = word        temp['tfidf'] = tfidf        result.append(temp)    result.sort(lambda x,y : -cmp(x['tfidf'], y['tfidf']))      return result

第一個函數：計算word在text的詞頻

wordlist是list格式的word，text是對應的document，python中的string格式

第二個函數：計算word在語料庫中的TF-IDF

wordfreq是第一個函數的輸出結果，corpus是document的list儲存格式