我正在使用 nltk 和 python 從語料庫中提取 ngram，我需要將生成的 ngram 保存在文本文件中。我試過這段代碼，但沒有結果：import nltk, re, string, collectionsfrom nltk.util import ngrams with open("titles.txt", "r", encoding='utf-8') as file:    text = file.read()tokenized = text.split()Monograms = ngrams(tokenized, 1)MonogramFreq = collections.Counter(Monograms)with open('output.txt', 'w') as f:       f.write(str(MonogramFreq))這是titles.txt的示例：Joli appartement s3 aux jardins de carthage mz823Villa 600m2 haut standing à hammametHammem lifS2 manzah 7Terrain constructible de 252m2 cl?turéTerrain nu a gammarthTerrain agrecole al fahesBureau 17 piècesUsine 5000m2 mannoubaMongramFreq 的簡單打印必須給出如下內容：('atelier',): 17, ('430',): 17, ('jabli',): 17, ('mall',): 17, ('palmeraies',): 17, ('r4',): 17, ('dégagée',): 17, ('fatha',): 17但甚至沒有創建output.txt文件。我更正了我的代碼如下：import nltk, re, string, collectionsfrom nltk.util import ngrams with open("titles.txt", "r", encoding='utf-8') as file:text = file.read()tokenized = text.split()Threegrams = ngrams(tokenized, 3)ThreegramFreq = collections.Counter(Threegrams)for i in ThreegramFreq.elements():with open('output.txt', 'a') as w:w.write(str(i))w.close()但是我需要在 output.txt 文件中包含每個 3-gram 的頻率。怎么做 ？