machine learning - show feature names after feature selection

Question

I need to build a classifier for text, and now I'm using TfidfVectorizer and SelectKBest to selection the features, as following:

vectorizer = TfidfVectorizer(sublinear_tf = True, max_df = 0.5, stop_words = 'english',charset_error='strict')

X_train_features = vectorizer.fit_transform(data_train.data)
y_train_labels = data_train.target;

ch2 = SelectKBest(chi2, k = 1000)
X_train_features = ch2.fit_transform(X_train_features, y_train_labels)

I want to print out selected features name(text) after select k best features, is there any way to do that? I just need to print out selected feature names, maybe I should use CountVectorizer instead?

Answer 1

The following should work:

np.asarray(vectorizer.get_feature_names())[ch2.get_support()]