django-separated

Class-based view and mixins for responding with CSV in Django. django-separated supports Django 1.3+.

Installation

$ pip install django-separated

Documentation

Views

separated.views.CsvView

A ListView that returns a CsvResponse.

You can specify the data for each row using the columns attribute. columns should be an iterable of 2-tuples where the first index is an accessor to get the value off of an object and the second is a column header.

class UserCsvView(CsvView):
    model = User
    columns = [
        ('first_name', 'First name'),
        ('last_name', 'Last name'),
        ('email', 'Email'),
    ]

The accessor can be a string or a callable. If it isn't a callable, it will be passed into attrgetter to turn into a callable. If the accessor returns a callable, it will be called. All of the following are valid examples of accessors:

• first_name
• first_name.upper
• get_absolute_url
• lambda x: x.upvotes.count() - x.downvotes.count()

There is a corresponding get_columns method if you need to have more dynamic behavior.

The header index is optional, if you want a header to be generated from the accessor, you can write a simpler columns declaration:

class UserCsvView(CsvView):
    model = User
    columns = [
        'first_name',
        'last_name',
        'email',
    ]

Additionally, you can specify the filename of the CSV file that will be downloaded. It will default to the model name + _list.csv if you don't provide one. For example:

class UserCsvView(CsvView):
    model = User

will have a filename of user_list.csv. But you can override it by settings the filename attribute. There is a corresponding get_filename that you can override for more complicated behavior.

By default, CsvView will output the headers as the first line. If you want to suppress this behavior, set output_headers to False.

separated.views.CsvResponseMixin

A MultipleObjectMixin subclass that returns a CsvResponse.

This is useful in instances where you want to substitute BaseListView for a ListView of your own. CsvResponseMixin supports all the behavior mentioned in CsvView, the only machinery you need to hook it up is a View class that calls render_to_response with a context that has a queryset available in the object_list key.

class MyWeirdBaseListView(View):
    def get(self, request, *args, **kwargs):
        return self.render_to_response({
            'object_list': User.objects.all(),
        })

class MyWeirdCsvView(CsvResponseMixin, MyWeirdBaseListView):
    pass

separated.views.CsvResponse

A subclass of HttpResponse that will download as CSV. CsvResponse requires a filename as the first argument of the constructor.

Admin

You can use django-separated in the admin center to export CSV from the admin site.

from separated.admin import CsvExportModelAdmin

class NewsAdmin(CsvExportModelAdmin):
    csv_export_columns = [
        'title',
        'pub_date',
        'author.full_name',
    ]

This adds an action to the change list.

csv_export_columns corresponds to the CsvView.columns attribute. If you want more fine-grained control, you can override csv_export_view_class instead:

from datetime import datetime

from separated.admin import CsvExportModelAdmin
from separated.views import CsvView

class NewsCsvView(CsvView):
    columns = [
        'title',
        'pub_date',
        'author.full_name',
    ]
    output_headers = False

    def get_filename(self, model):
        return '%s-news-export.csv' % datetime.today().strftime('Y-m-d')

class NewsAdmin(CsvExportModelAdmin):
    csv_export_view_class = NewsCsvView

csv_export_columns and csv_export_view_class also exist as methods (get_csv_export_columns and get_csv_export_view_class respectively) if you need change them based on request.

from separated.admin import CsvExportModelAdmin

class NewsAdmin(CsvExportModelAdmin):
    staff_export_columns = (
        'title',
        'pub_date',
        'author.full_name',
    )

    superuser_export_columns = staff_export_columns + (
        'secret_column',
    )

    def get_csv_export_columns(self, request):
        if request.user.is_superuser:
            return self.superuser_export_columns
        else:
            return self.staff_export_columns

Getters

django-separated provides a couple of helpers for normalizing the data that comes off of the model before sending it to the CSV writer. These are all based on a Getter class which handles the different types of accessors.

separated.utils.BooleanGetter

If you have a boolean value that you wish to be transformed into Yes or No, you can use the BooleanGetter:

from separated.utils import BooleanGetter

class UserCsvView(CsvView):
    model = User
    columns = [
        BooleanGetter('is_admin'),
    ]

separated.utils.DisplayGetter

If you have a model field that has choices and you want the human readable display to appear in the CSV, you can use the DisplayGetter:

from separated.utils import BooleanGetter

class User(models.Model):
    favorite_color = models.CharField(max_length=255,
        choices=(
            ('blue', 'Blue'),
            ('green', 'Green'),
            ('red', 'Red'),
        ))

class UserCsvView(CsvView):
    model = User
    columns = [
        DisplayGetter('favorite_color'),
    ]

This will end up using the get_favorite_color_display method that Django automatically adds.