我该如何使用scikit-learn库中的TF-IDF向量化器提取推文的unigrams和bigrams?我想用输出结果来训练分类器。
以下是scikit-learn的代码:
from sklearn.feature_extraction.text import TfidfVectorizer
corpus = [
'This is the first document.',
'This document is the second document.',
'And this is the third one.',
'Is this the first document?',
]
vectorizer = TfidfVectorizer()
X = vectorizer.fit_transform(corpus)