"Export to CSV" action for django admin

actions.py

import unicodecsv
from django.http import HttpResponse

def export_as_csv_action(description="Export selected objects as CSV file",
                         fields=None, exclude=None, header=True):
    """
    This function returns an export csv action
    'fields' and 'exclude' work like in django ModelForm
    'header' is whether or not to output the column names as the first row
    """
    def export_as_csv(modeladmin, request, queryset):
        opts = modeladmin.model._meta
        
        if not fields:
            field_names = [field.name for field in opts.fields]
        else:
            field_names = fields

        response = HttpResponse(mimetype='text/csv')
        response['Content-Disposition'] = 'attachment; filename=%s.csv' % unicode(opts).replace('.', '_')

        writer = unicodecsv.writer(response, encoding='utf-8')
        if header:
            writer.writerow(field_names)
        for obj in queryset:
            row = [getattr(obj, field)() if callable(getattr(obj, field)) else getattr(obj, field) for field in field_names]
            writer.writerow(row)
        return response
    export_as_csv.short_description = description
    return export_as_csv

admin.py

from django.contrib import admin
from repsf.map.models import Location
from django.http import HttpResponse, HttpResponseForbidden
from actions import export_as_csv_action

class SpamAdmin(admin.ModelAdmin):
	list_display = ['wink','nudge']
	actions = [export_as_csv_action("CSV Export", fields=['wink','nudge'])]
	
admin.site.register(Location, LocationAdmin)

in newer version of python and httpResponse, it should be

        response = HttpResponse(content_type='text/csv')
        response['Content-Disposition'] = 'attachment; filename=%s.csv' % str(opts).replace('.', '_')

This is great. Does the exclude argument do anything though?

Could the exclude argument be used like this?

if not fields:
    field_names = [field.name for field in meta.fields]
else:
    field_names = fields

if exclude:
    exclude_names = exclude.split() if isinstance(exclude, str) else exclude  # exclude could be a string
    field_names = [x for x in field_names if x not in list(exclude_names)]

Here exclude could be passed in as a list, a tuple, or a string.

*Corrected an error - must assign exclude to a new variable 'exclude_names', or local variable referenced before assignment error will be thrown

Amazing job on this one

Sometimes it can be useful to follow foreign keys If that is what you need you can use:

def rgetattr(obj, attr, *args):
    def _getattr(obj, attr):
        return getattr(obj, attr, *args)
    return functools.reduce(_getattr, [obj] + attr.split('__'))

Just import functools and be careful not to go too deep Django docs for the QuerySet API.