Pickle Tfidfvectorizer 以及自定义分词器

Question

我正在使用服装分词器传递给 TfidfVectorizer。该分词器依赖于另一个文件中的外部 class TermExtractor。

我基本上是想根据某些条款构建一个TfidVectorizer，而不是所有单一的words/tokens。

代码如下：

from sklearn.feature_extraction.text import TfidfVectorizer
from TermExtractor import TermExtractor

extractor = TermExtractor()

def tokenize_terms(text):
    terms = extractor.extract(text)
    tokens = []
    for t in terms:
        tokens.append('_'.join(t))
    return tokens


def main(): 
    vectorizer = TfidfVectorizer(lowercase=True, min_df=2, norm='l2', smooth_idf=True, stop_words=stop_words, tokenizer=tokenize_terms)
    vectorizer.fit(corpus)
    pickle.dump(vectorizer, open("models/terms_vectorizer", "wb"))

这运行良好，但每当我想重新使用此 TfidfVectorizer 并用 pickle 加载它时，我都会收到错误消息：

vectorizer = pickle.load(open("models/terms_vectorizer", "rb"))

Traceback (most recent call last):
  File "./train-nps-comments-classifier.py", line 427, in <module>
    main()
  File "./train-nps-comments-classifier.py", line 325, in main
    vectorizer = pickle.load(open("models/terms_vectorizer", "rb"))
  File "/usr/lib/python2.7/pickle.py", line 1378, in load
    return Unpickler(file).load()
  File "/usr/lib/python2.7/pickle.py", line 858, in load
    dispatch[key](self)
  File "/usr/lib/python2.7/pickle.py", line 1090, in load_global
    klass = self.find_class(module, name)
  File "/usr/lib/python2.7/pickle.py", line 1126, in find_class
    klass = getattr(mod, name)
AttributeError: 'module' object has no attribute 'tokenize_terms'

Python pickle 在依赖 class 时如何工作？

Answer 1

弄清楚，我需要在加载 pickled TfidVectorizer 的相同代码中添加方法 tokenize_terms()，导入 TermExtractor，并创建一个提取器：

extractor = TermExtractor()

Pickle Tfidfvectorizer 以及自定义分词器

Pickle Tfidfvectorizer along with a custom tokenizer

python

pickle

tf-idf

scikit-learn