def __tfidf_vectors(values):
tfidf_matrix = TfidfVectorizer().fit_transform(values)
split_index = int(tfidf_matrix.get_shape()[0] / 2)
tfidf_array = tfidf_matrix.todense()
df_result1 = [row.tolist()[0] for row in tfidf_array[0:split_index]]
df_result2 = [row.tolist()[0] for row in tfidf_array[split_index:]]
return df_result1, df_result2
