使用 *args 和 **kwargs 在 Django 中进行动态查询

Question

我正在尝试创建一个搜索表单，用户可以在其中选择几个选项来过滤搜索。我收到此错误：

sortedByScore() argument after * must be a sequence, not Q

views.py:

def results(request):
    if request.method != "GET":
        return HttpResponse("request method needs to be GET")
    else:
        bound_search_form = SearchForm(request.GET)
        query = request.GET['query']
        subject = request.GET['subject']
        grade = request.GET['grade']
        order_by = request.GET['order_by']
        kwargs = {}
        args = ()
        if query:
            query_word_list = query.split()
            args = reduce(operator.or_, ((Q(title__contains=x) | Q(content__contains=x)) for x in query_word_list))
        if subject != 'all':
            kwargs["subject"] = subject

        summaries_list = Summary.objects.sortedByScore(*args, **kwargs)
        length = len(summaries_list)

        # pagination
        paginator = Paginator(summaries_list, 4)

        # get page number from GET request
        page_num = request.GET.get('page', 1)

        # get summaries from paginator according to page number
        try:
            summaries = paginator.page(page_num)
        except(EmptyPage, InvalidPage):
            summaries = paginator.page(paginator.num_pages)

        context_dict = {
            'sumAmount': length,
            'summaries': summaries,
            'search_form': bound_search_form,
        }

        return render(request, 'results.html', context_dict)

我的自定义管理器的代码 sortedByScore:

class SummaryManager(models.Manager):
    def sortedByScore(self, *args, **kwargs):
        summaries = self.get_queryset().filter(*args, **kwargs)
        return sorted(summaries, key=lambda summary: summary.get_score(),reverse=True)

Answer 1

您 sortedByScore(*args, **kwargs) 的第一个参数是一个 Q 对象：

args = reduce(operator.or_, ((Q(title__contains=x) | Q(content__contains=x)) for x in query_word_list))

您需要重新定义您的方法以传入不同的参数and/or在方法中执行reduce。

Answer 2

args = reduce(operator.or_, ((Q(title__contains=x) | Q(content__contains=x)) for x in query_word_list))

reduce 将可迭代对象减少为单个对象，因此在这一行之后 args 不是可迭代对象。这将 args 减少为单个 Q 对象，OR 将 query_word_list 中的所有项目放在一起。如果你想使用 * 语法传递它，你需要将它包装在一个可迭代的对象中，即 args = (args,).

使用 *args 和 **kwargs 在 Django 中进行动态查询

Dynamic querys in Django using *args and **kwargs

python

django

django-forms

django-queryset

django-views