Streaming a CSV file in Django

Question

I am attempting to stream a csv file as an attachment download. The CSV files are getting to be 4MB in size or more, and I need a way for the user to actively download the f

Answer 1

The middleware issue has been solved as of Django 1.5 and a StreamingHttpResponse has been introduced. The following should do:

import cStringIO as StringIO
import csv

def csv_view(request):
    ...
    # Assume `rows` is an iterator or lists
    def stream():
        buffer_ = StringIO.StringIO()
        writer = csv.writer(buffer_)
        for row in rows:
            writer.writerow(row)
            buffer_.seek(0)
            data = buffer_.read()
            buffer_.seek(0)
            buffer_.truncate()
            yield data
    response = StreamingHttpResponse(
        stream(), content_type='text/csv'
    )
    disposition = "attachment; filename=file.csv"
    response['Content-Disposition'] = disposition
    return response

There's some documentation on how to output csv from Django but it doesn't take advantage of the StreamingHttpResponse so I went ahead and opened a ticket in order to track it.