count_vect = CountVectorizer()
X_train_counts = count_vect.fit_transform(corpus)
tfidf_transformer = TfidfTransformer()
X_train_tfidf = tfidf_transformer.fit_transform(X_train_counts)
X_ch2 = SelectKBest(chi2, k=10)
X_train_ch2 = X_ch2.fit_transform(X_train_counts, Y_train)
classifier = LinearSVC().fit(X_train_ch2, Y_train)