对象表单没有属性 'has_header'

我是新的b。 django. 我有一个新闻应用程序，一个显示每个新闻的页面的视图：

def news_page/request, news_id/:

 news = News.objects.get/pk=news_id/

 tags = news.tags.all//

 category = news.category

 comments = news.comment_set.all//

 form = add_comment/request, news.id/

 return render/request, 'news/news_page.html', {'form': form, 'news': news, 'tags': tags, 'category': category, 'user': request.user, 'comments': comments}/

我创建了一个评论的应用程序：
models.py:

class Comment/models.Model/:

 author = models.ForeignKey/User/

 comment_body = models.CharField/max_length=500/

 news = models.ForeignKey/News/

 pub_date = models.DateTineField/default = datetime.datetime.now///

forms.py:

class AddCommentForm/ModelForm/:

 comment_body = forms.CharField/widget=forms.Textarea/



 class Meta//:

 model = Comment

 exclude = /'author', 'news','pub_date',/

我会尝试实现一个函数 comments.view add_comment, 哪种用途 news_page view /更高/ :

def add_comment/request, news_id/:

 news = News.objects.get/pk=news_id/

 if request.method == 'POST':

 form = AddCommentForm/request.POST/

 if form.is_valid:

 comment = form.save/commit=False/

 comment.author = request.user

 comment.news = news

 comment.save//

 else:

 form = AddCommentForm//

 return form

但我有一个错误 'AddCommentForm' 对象没有属性 'has_header' . 我认为这是因为在演示中 add_comment 不是 HttpResponse. 我该如何重写代码来工作？
调试关于错误的消息

Internal Server Error: /news/15/comment/

Traceback /most recent call last/:

 File "C:\Python27\myproject\djcode\first_venv\venv\lib\site-packages\django\core\handlers\base.py"

, line 187, in get_response

 response = middleware_method/request, response/

 File "C:\Python27\myproject\djcode\first_venv\venv\lib\site-packages\django\contrib\sessions\middl

eware.py", line 26, in process_response

 patch_vary_headers/response, /'Cookie',//

 File "C:\Python27\myproject\djcode\first_venv\venv\lib\site-packages\django\utils\cache.py", line

142, in patch_vary_headers

 if response.has_header/'Vary'/:

AttributeError: 'AddCommentForm' object has no attribute 'has_header'

谢！