django-separated 1.1.0

Serializer

separated.utils.ColumnSerializer

You can use the ColumnSerializer to generate CSV. It accepts a column definition, and returns a callable that you can use to serialize to CSV.

from separated.utils import ColumnSerializer

serialize_books = ColumnSerializer([
    ('title', 'Title'),
    ('pub_date', 'Publication Date'),
    ('isbn', 'ISBN'),
])
with open('/tmp/books.csv', 'wb') as f:
    books = Book.objects.all()
    serialize_books(books, file=f)

The column definition is an iterable of 2-tuples where the first item is an accessor to get the value off of an object and the second item is the column header.

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()

You can even stretch across relationships:

• 'author'

• 'author.name'

• 'author.book_count'

• 'author.user.username'

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

serialize_books = ColumnSerializer([
    'title',  # Header will be 'Title'
    'pub_date',  # Header will be 'Pub date'
])

You can mix and match the two styles as well.

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

Views

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

class UserCsvView(CsvView):
    model = User

class UserCsvView(CsvView):
    model = False
    output_headers = False

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

class MyWeirdCsvView(CsvResponseMixin, MyWeirdBaseListView):
    pass

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.

from separated.utils import BooleanGetter

user_serializer = ColumnSerializer([
    BooleanGetter('is_admin'),
])

from separated.utils import BooleanGetter

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

user_serializer = ColumnSerializer([
    DisplayGetter('favorite_color'),
])