Having Django serve downloadable files

For the "best of both worlds" you could combine S.Lott's solution with the xsendfile module: django generates the path to the file (or the file itself), but the actual file serving is handled by Apache/Lighttpd. Once you've set up mod_xsendfile, integrating with your view takes a few lines of code:

from django.utils.encoding import smart_str

response = HttpResponse(mimetype='application/force-download') # mimetype is replaced by content_type for django 1.7
response['Content-Disposition'] = 'attachment; filename=%s' % smart_str(file_name)
response['X-Sendfile'] = smart_str(path_to_file)
# It's usually a good idea to set the 'Content-Length' header too.
# You can also set any other required headers: Cache-Control, etc.
return response

Of course, this will only work if you have control over your server, or your hosting company has mod_xsendfile already set up.

EDIT:

mimetype is replaced by content_type for django 1.7

response = HttpResponse(content_type='application/force-download')

EDIT: For nginx check this, it uses X-Accel-Redirect instead of apache X-Sendfile header.

A "download" is simply an HTTP header change.

See http://docs.djangoproject.com/en/dev/ref/request-response/#telling-the-browser-to-treat-the-response-as-a-file-attachment for how to respond with a download.

You only need one URL definition for "/download".

The request's GET or POST dictionary will have the "f=somefile.txt" information.

Your view function will simply merge the base path with the "f" value, open the file, create and return a response object. It should be less than 12 lines of code.

For a very simple but not efficient or scalable solution, you can just use the built in django serve view. This is excellent for quick prototypes or one-off work, but as has been mentioned throughout this question, you should use something like apache or nginx in production.

from django.views.static import serve
filepath = '/some/path/to/local/file.txt'
return serve(request, os.path.basename(filepath), os.path.dirname(filepath))

S.Lott has the "good"/simple solution, and elo80ka has the "best"/efficient solution. Here is a "better"/middle solution - no server setup, but more efficient for large files than the naive fix:

http://djangosnippets.org/snippets/365/

Basically, Django still handles serving the file but does not load the whole thing into memory at once. This allows your server to (slowly) serve a big file without ramping up the memory usage.

Again, S.Lott's X-SendFile is still better for larger files. But if you can't or don't want to bother with that, then this middle solution will gain you better efficiency without the hassle.

Just mentioning the FileResponse object available in Django 1.10

Edit: Just ran into my own answer while searching for an easy way to stream files via Django, so here is a more complete example (to future me). It assumes that the FileField name is imported_file

views.py

from django.views.generic.detail import DetailView   
from django.http import FileResponse
class BaseFileDownloadView(DetailView):
  def get(self, request, *args, **kwargs):
    filename=self.kwargs.get('filename', None)
    if filename is None:
      raise ValueError("Found empty filename")
    some_file = self.model.objects.get(imported_file=filename)
    response = FileResponse(some_file.imported_file, content_type="text/csv")
    # https://docs.djangoproject.com/en/1.11/howto/outputting-csv/#streaming-large-csv-files
    response['Content-Disposition'] = 'attachment; filename="%s"'%filename
    return response

class SomeFileDownloadView(BaseFileDownloadView):
    model = SomeModel

urls.py

...
url(r'^somefile/(?P<filename>[-\w_\\-\\.]+)$', views.SomeFileDownloadView.as_view(), name='somefile-download'),
...

Having Django serve downloadable files

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