如何将 django 管理更改列表导出为 csv

Question

I want to export my changelist (fields in list_display ) as csv. I used the code from https://books.agiliq.com/projects/django-admin-cookbook/en/latest/export.html But it creates csv for the model fields. But in my case, I want to export changelist as csv, not the model fields. Also, note that most of the fields in changelist( list_display ) are calculated fields in Admin.

This is my code

class ExportCsvMixin:

    def export_as_csv(self, request, queryset):

        meta = queryset.model._meta
        field_names = [field.name for field in meta.fields]

        response = HttpResponse(content_type='text/csv')
        response['Content-Disposition'] = 'attachment; filename={}.csv'.format(meta)
        writer = csv.writer(response)

        writer.writerow(field_names)
        for obj in queryset:
            row = writer.writerow([getattr(obj, field) for field in field_names])

        return response

    export_as_csv.short_description = "Export Selected"


class MyAdmin(admin.ModelAdmin, ExportCsvMixin):
    list_display = ('field1',
                    'field2'
           )
    list_filter = ('field2')
    actions = ["export_as_csv"]

    def field1(self, obj):
        <return logic here>

    def field2(self, obj):
        <return logic here>

NOTE:

1. field1 and field2 are calculated fields, and not model fields.
2. My model is a proxy model. But I don't think it would any difference in this case.

I want the csv to contain data for field1 and field2 only, as they are in my changelist. May be the trick would be to somehow point the queryset to that of changelist. but how do that ? Or if someone can suggest some other solution or even api to achieve this goal?

Answer 1

I had the same issue and I managed to hack it this way.

• I looked into the ModelAdmin base class and I found the function responsible for handling actions methods, it's called response_action , I looked into it and changed the queryset it return what I need.

Let say you have a query set that return 'field1' and 'field2'.

Here is how I edited the function to return a custom queryset:

def response_action(self, request, queryset):
        """
        Handle an admin action. This is called if a request is POSTed to the
        changelist; it returns an HttpResponse if the action was handled, and
        None otherwise.
        """

        # There can be multiple action forms on the page (at the top
        # and bottom of the change list, for example). Get the action
        # whose button was pushed.
        try:
            action_index = int(request.POST.get('index', 0))
        except ValueError:
            action_index = 0

        # Construct the action form.
        data = request.POST.copy()
        data.pop(admin.helpers.ACTION_CHECKBOX_NAME, None)
        data.pop("index", None)

        # Use the action whose button was pushed
        try:
            data.update({'action': data.getlist('action')[action_index]})
        except IndexError:
            # If we didn't get an action from the chosen form that's invalid
            # POST data, so by deleting action it'll fail the validation check
            # below. So no need to do anything here
            pass

        action_form = self.action_form(data, auto_id=None)
        action_form.fields['action'].choices = self.get_action_choices(request)

        # If the form's valid we can handle the action.
        if action_form.is_valid():
            action = action_form.cleaned_data['action']
            select_across = action_form.cleaned_data['select_across']
            func = self.get_actions(request)[action][0]

            # Get the list of selected PKs. If nothing's selected, we can't
            # perform an action on it, so bail. Except we want to perform
            # the action explicitly on all objects.
            selected = request.POST.getlist(admin.helpers.ACTION_CHECKBOX_NAME)
            if not selected and not select_across:
                # Reminder that something needs to be selected or nothing will
                # happen
                msg = _("Items must be selected in order to perform "
                        "actions on them. No items have been changed.")
                self.message_user(request, msg, messages.WARNING)
                return None

            if not select_across:
                ##### change this line with your queryset that return field one and two
                queryset = 'your_queryset_with_field'

            response = func(self, request, queryset)

            # Actions may return an HttpResponse-like object, which will be
            # used as the response from the POST. If not, we'll be a good
            # little HTTP citizen and redirect back to the changelist page.
            if isinstance(response, HttpResponseBase):
                return response
            else:
                return HttpResponseRedirect(request.get_full_path())
        else:
            msg = _("No action selected.")
            self.message_user(request, msg, messages.WARNING)
            return None

Check in this function the part I command with ##### redefine that function in the class that inherits from the model admin class

The function returns a custom queryset , now you can edit your export_as_csv_function according to that.

def export_as_csv(self, request, queryset):

        field_names = ["field_one", "field_two"]

        response = HttpResponse(content_type='text/csv')
        response['Content-Disposition'] = 'attachment; filename={}.csv'.format(
            'working_hours')
        writer = csv.writer(response)

        writer.writerow(field_names)
        for obj in queryset:
            writer.writerow([obj.get(field) for field in field_names])

        return response

That it and you can go and download your CSV with the customs field.

I hope it's not too late and this helps other folks with the same issue.