Returning CSV format from django-rest-framework?

Question

I have a working Django 1.8 site, and I want to add a RESTful API using django-rest-framework. I would like to support rendering to CSV and JSON formats, and am puzzling over ho

Answer 1

If you just need to download CSV (without Model serialization etc)

import csv
from django.http import HttpResponse
from rest_framework.views import APIView


class CSVviewSet(APIView):

    def get(self, request, format=None):
        response = HttpResponse(content_type='text/csv')
        response['Content-Disposition'] = 'attachment; filename="export.csv"'
        writer = csv.DictWriter(response, fieldnames=['emp_name', 'dept', 'birth_month'])
        writer.writeheader()
        writer.writerow({'emp_name': 'John Smith', 'dept': 'Accounting', 'birth_month': 'November'})
        writer.writerow({'emp_name': 'Erica Meyers', 'dept': 'IT', 'birth_month': 'March'})
        return response

Answer 2

Got it. The trick is to install djangorestframework-csv, then add the following in settings:

REST_FRAMEWORK = {
    'DEFAULT_RENDERER_CLASSES': (
        'rest_framework.renderers.JSONRenderer',
        'rest_framework.renderers.BrowsableAPIRenderer',
        'rest_framework_csv.renderers.CSVRenderer',
    ),
}

And then scrap the JSONResponse function in views.py and just do return Response(serializer.data) instead. Very easy in the end.

Answer 3

This is an old post, but I've seen the accepted answer sets the CSVRenderer as one of the defaults, which is not usually wanted.

I would implement the view this way:

...
from rest_framework.viewsets import ModelViewSet
from rest_framework.settings import api_settings
from rest_framework_csv.renderers import CSVRenderer
from .... import OrgSerializer
...

class OrganizationViewSet(ModelViewSet):

    queryset = Organisation.objects.all()
    http_method_names = ['get', '...list all the other verbs you want']
    serializer_class = OrgSerializer
    renderer_classes = tuple(api_settings.DEFAULT_RENDERER_CLASSES) + (CSVRenderer,)

    def get_queryset(self):
        if 'code' in self.request.GET:
            code = self.request.GET['code']
            return Organisation.objects.filter(code=code)
        return Organisation.objects.all()

Of course, having the django-rest-framework-csv installed and OrgSerializer defined somewhere.

Then you can just set 'rest_framework.renderers.JSONRenderer' as your default renderer in settings and the rest framework will automatically return csv content if you request it on the HTTP_ACCEPT header - just for this view.

Answer 4

I think that a StreamingHttpResponse should be the preferred way. With django-storages and ViewSet it looks more or less like this.

    @action(detail=True, methods=["get"])
    def download(self, request, pk=None):
        f = self.get_object()
        response = StreamingHttpResponse(
            streaming_content=f.file.chunks(), content_type="text/csv"
        )
        response[
            "Content-Disposition"
        ] = f'attachment; filename="{f.name}.csv"'
        response.status_code = status.HTTP_200_OK
        return response

Also, FileResponse is basically a StreamingHttpResponse with some headers etc so both are great for this use case.