我得到一个有趣的例外。
如果我有这样的代码：
{% if page_nr != 0 %}
<a href="{% url 'post:detail' topic.id page_nr|increase:-1 %}">Previous Page</a>
{% endif %}
{%page_not_over_amount page_nr amount_comments limit_amount_comment%}
{% if comment_not_over_amount %}
<a href="{% url 'post:detail' topic.id page_nr|increase:1 %}">Next Page</a>
{% endif %}
我会得到一个例外： 模板渲染期间出错 在模板C：\ Users \ Nutzer \ PycharmProjects \ selfTry \ post \ templates \ post \ comment_block.html中，错误在行 必须是str，而不是int
第22行
<a href="{% url 'post:detail' topic.id page_nr|increase:-1 %}">Previous Page</a>
但是，如果我删除自定义标记，请将代码设为：
{% if page_nr != 0 %}
<a href="{% url 'post:detail' topic.id page_nr|increase:-1 %}">Previous Page</a>
{% endif %}
{% if comment_not_over_amount %}
<a href="{% url 'post:detail' topic.id page_nr|increase:1 %}">Next Page</a>
{% endif %}
异常消失了！ 这是我的自定义标记和过滤条件：
@register.inclusion_tag('post/comment_block.html')
def page_not_over_amount(page_nr, comment_amount, comment_limit):
result = page_nr * comment_limit < comment_amount - comment_limit
return {'comment_not_over_amount': result}
@register.filter(name='increase')
def increase_variable(value, increase):
data = value + increase
return data
@register.inclusion_tag('post/comment_block.html')
def limit_amount_in_a_page(page_nr, topic_id=1, amount=5):
topic = get_object_or_404(Topic,id=topic_id)
comments = Comment.objects.filter(topic=topic)
selected_comments = []
starting_index = page_nr*amount
for index in range(starting_index, starting_index + amount):
if index >= len(comments):
break;
selected_comments.append(comments[index])
return {
'topic': topic,
'page_nr': page_nr,
'selected_comments': selected_comments,
'amount_comments': comments.all().count(),
'limit_amount_comment': amount,
}
其他观点：
def index(request):
all_topics = Topic.objects.all()
context = {
'my_topics': all_topics,
}
return render(request, 'post/index.html', context)
def detail(request, topic_id, page_nr):
topic = get_object_or_404(Topic, id=topic_id)
form = CommentForm()
comments = Comment.objects.filter(topic=topic)
return render(request, 'post/detail.html', {
'topic': topic,
'form': form,
'comments': comments,
'page_nr': int(page_nr),
})
@csrf_protect
def comment(request, topic_id, user_id):
# if this is a POST request we need to process the form data
topic = get_object_or_404(Topic, id=topic_id)
# try:
if request.method == 'POST':
# create a form instance and populate it with data from the request:
form = CommentForm(request.POST)
# check whether it's valid:
if form.is_valid():
# process the data in form.cleaned_data as required
text = form.cleaned_data['comment']
args = {'form': form, 'topic': topic}
# save the data in database
save_comments_into_database(topic, int(user_id), text)
# redirect to a new URL:
return HttpResponseRedirect('../..', args)
# if a GET (or any other method) we'll create a blank form
else:
form = CommentForm()
return render(request, 'post/detail.html', {'form': form, 'topic': topic})
以下是所有追溯：
Environment:
Request Method: GET
Request URL: http://127.0.0.1:8000/post/1/0/
Django Version: 1.11.3
Python Version: 3.6.2
Installed Applications:
['post.apps.PostConfig',
'music.apps.MusicConfig',
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware']
Template error:
In template C:\Users\Nutzer\PycharmProjects\selfTry\post\templates\post\comment_block.html, error at line 22
must be str, not int
Traceback:
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site- packages\django\core\handlers\exception.py" in inner
41. response = get_response(request)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\core\handlers\base.py" in _get_response
187. response = self.process_exception_by_middleware(e, request)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\core\handlers\base.py" in _get_response
185. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\Nutzer\PycharmProjects\selfTry\post\views.py" in detail
27. 'page_nr': int(page_nr),
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\shortcuts.py" in render
30. content = loader.render_to_string(template_name, context, request, using=using)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\loader.py" in render_to_string
68. return template.render(context, request)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\backends\django.py" in render
66. return self.template.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
207. return self._render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in _render
199. return self.nodelist.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
990. bit = node.render_annotated(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
957. return self.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\library.py" in render
245. return t.render(new_context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
209. return self._render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in _render
199. return self.nodelist.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
990. bit = node.render_annotated(context)
ile "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
957. return self.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\library.py" in render
245. return t.render(new_context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
209. return self._render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in _render
199. return self.nodelist.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
990. bit = node.render_annotated(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
957. return self.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\defaulttags.py" in render
322. return nodelist.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
990. bit = node.render_annotated(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
957. return self.render(context)
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\defaulttags.py" in render
441. args = [arg.resolve(context) for arg in self.args]
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\defaulttags.py" in <listcomp>
441. args = [arg.resolve(context) for arg in self.args]
File "C:\Users\Nutzer\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in resolve
736. new_obj = func(obj, *arg_vals)
File "C:\Users\Nutzer\PycharmProjects\selfTry\post\templatetags\post_filters.py" in increase_variable
10. data = value + increase
Exception Type: TypeError at /post/1/0/
Exception Value: must be str, not int
答案 0 :(得分：0)
File "C:\Users\Nutzer\PycharmProjects\selfTry\post\templatetags\post_filters.py" in increase_variable
10. data = value + increase
这是引发TypeError的地方我在page_not_over_amount方法中没有看到这一点，所以你必须手动调试它。
答案 1 :(得分：0)
你必须转换为int
data = int(value) + int(increase)