Summarize any text in 13 sentences using Sumy

summarize.py

from sumy.parsers.plaintext import PlaintextParser
from sumy.nlp.tokenizers import Tokenizer
from sumy.summarizers.lsa import LsaSummarizer

with open('transcript.txt') as in_file:
    text = in_file.read()
    parser = PlaintextParser.from_string(text, Tokenizer("english"))
    summarizer = LsaSummarizer()

    num_sentences = 13
    summary = summarizer(parser.document, num_sentences)  # The number '3' indicates the number of sentences in the summary
    with open('summarized_transcript.txt', mode='w') as out_file:
        for sentence in summary:
            out_file.write(str(sentence) + '\n')