如何将结果追加到列表中？

Question

我有CSV文件包含评论，我正在做一些NLP预处理（令牌化，阻止..etc）我在最终结果中只有一个问题。这是我的代码：

def clean_doc(r):
            stop_free = " ".join([i for i in r.lower().split() if i not in stop])
            punc_free = ''.join(ch for ch in stop_free if ch not in exclude)
            normalized = " ".join(lemma.lemmatize(word) for word in punc_free.split())
            stemmed = "".join([stemmer.stem(i) for i in normalized])
            return stemmed
##----------------------------------------------------------------------
with open('test.csv', 'r') as csvfile:
 data = csv.reader(csvfile, delimiter=',')
 stemmer = PorterStemmer()
 stop = set(stopwords.words('english'))
 exclude = set(string.punctuation) 
 lemma = WordNetLemmatizer()
 texts = []
 next(data)
 for row in data:
    r = row[1]
    texts.append(clean_doc(r))
 print(texts)

变量（文本）不会打印任何内容。有谁能告诉我我哪里错了？...提前致谢