def get_preserved_filters(self, request):
        match = request.resolver_match
        if self.preserve_filters and match:
            opts = self.model._meta
            current_url = '%s:%s' % (match.app_name, match.url_name)
            changelist_url = 'admin:%s_%s_changelist' % (opts.app_label, opts.model_name)
            if current_url == changelist_url:
                preserved_filters = request.GET.urlencode()
            else:
                preserved_filters = request.GET.get('_changelist_filters')

            if preserved_filters:
                return urlencode({'_changelist_filters': preserved_filters})
        return ''
Returns the preserved filters querystring.
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/contrib/admin/options.py/ModelAdmin.get_preserved_filters