def build_and_save_lsi_model():
print('Connecting to the database...')
sentences = SentencesIterator(tokens_generator)
dct = Dictionary(sentences)
# Corpus as dictionary ids lists, in memory
# Can be transformed in an iterable as done with the others if needed
print('Calculating the LSI model...')
bow_corpus = [dct.doc2bow(s) for s in sentences]
model = LsiModel(bow_corpus, id2word=dct)
model.print_debug()
model.save(LSI_MODEL_FILE)
for t in range(model.get_topics().shape[0]):
print(t)
print(model.print_topic(t))
