Create in-memory zip file with multiple in-memory CSVs to serve with Django

views.py

from django.http import HttpResponse

import io
import csv
from zipfile import ZipFile


def get_zip(request):
    # We generate rows for our different files
    first_csv_rows = generate_rows_for_first_csv() 
    second_csv_rows = generate_rows_for_second_csv()

    # We create file-like objects to be used as in-memory containers
    # CSV files requires to be StringIO while Zip files are binary files
    with io.BytesIO() as zip_buffer, io.StringIO() as first_csv, io.StringIO() as second_csv:
        
        # We create a writer for each of our CSV files
        first_writer = csv.writer(first_csv)
        second_writer = csv.writer(second_csv)
        
        # We write our rows in our CSV files
        first_writer.writerows(first_rows)
        second_writer.writerows(second_rows)
        
        # We create our Zip file from our file-like object
        with ZipFile(zip_buffer, 'w') as zip_file:
        
            # Then write our CSV file-like
            zip_file.writestr('first.csv', first_csv.getvalue())
            zip_file.writestr('second.csv', second_csv.getvalue())

        # Exiting the "with" statement closes the Zip file, effectivly "writing" data in our
        # file-like BytesIO object
        # We then pass the binary content of our binary file-like to our response
        response = HttpResponse(zip_buffer.getbuffer().tobytes(), content_type="application/zip")
        
    # Every file-like object is now closed
    # We precise our response has an attachement
    response['Content-disposition'] = 'attachement; filename=export.zip'

    # We return our response
    return response

Of course, if we've had more than two files, a "for" iteration would've been welcome, but for readability I kept it simple.