from django.conf import settings
from django.utils import translation


class AdminLocaleMiddleware:

    def process_request(self, request):
        if request.path.startswith('/admin'):
            request.LANG = getattr(settings, 'ADMIN_LANGUAGE_CODE',
                settings.LANGUAGE_CODE)
translation.activate(request.LANG)
request.LANGUAGE_CODE = request.LANG
Изменить локаль для django-admin-tools