Generating file to download with Django

Question

Is it possible to make a zip archive and offer it to download, but still not save a file to the hard drive?

Answer 1

To trigger a download you need to set Content-Disposition header:

from django.http import HttpResponse from wsgiref.util import FileWrapper  # generate the file response = HttpResponse(FileWrapper(myfile.getvalue()), content_type='application/zip') response['Content-Disposition'] = 'attachment; filename=myfile.zip' return response 

If you don't want the file on disk you need to use StringIO

import cStringIO as StringIO  myfile = StringIO.StringIO() while not_finished:     # generate chunk     myfile.write(chunk) 

Optionally you can set Content-Length header as well:

response['Content-Length'] = myfile.tell() 

Answer 2

You'll be happier creating a temporary file. This saves a lot of memory. When you have more than one or two users concurrently, you'll find the memory saving is very, very important.

You can, however, write to a StringIO object.

>>> import zipfile >>> import StringIO >>> buffer= StringIO.StringIO() >>> z= zipfile.ZipFile( buffer, "w" ) >>> z.write( "idletest" ) >>> z.close() >>> len(buffer.getvalue()) 778 

The "buffer" object is file-like with a 778 byte ZIP archive.