Django报错：NoReverseMatch: Reverse for 'xxx' not found . 'xxx' is not a valid view function or pattern

最近在学习Django，跟着做一个Django论坛从搭建到部署，教程链接也贴上：【第一部分-django论坛从搭建到部署】一个完整Django入门指南-苍云横渡，做到第三部分时候遇到一个问题，困扰了我很久。经查阅后仍是无果，官方文档也看了依然没有解决问题，后来突然发现了问题，再看看报错的情况，确实就是自己写的时候写错了。先把错误情况贴上：

Internal Server Error: /boards/1/Traceback (most recent call last): File "D:\IDE\Python\Anaconda\lib\site-packages\django\core\handlers\exception.py", line 34, in inner response = get_response(request) File "D:\IDE\Python\Anaconda\lib\site-packages\django\core\handlers\base.py", line 126, in _get_response response = self.process_exception_by_middleware(e, request) File "D:\IDE\Python\Anaconda\lib\site-packages\django\core\handlers\base.py", line 124, in _get_response response = wrapped_callback(request, *callback_args, **callback_kwargs) File "D:\IDE\pycharm\PyCharm Community Edition 2018.1.2\DjangoProjects\myproject\boards\views.py", line 33, in board_topics return render(request, 'topics.html', {'board': board}) File "D:\IDE\Python\Anaconda\lib\site-packages\django\shortcuts.py", line 36, in render content = loader.render_to_string(template_name, context, request, using=using) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\loader.py", line 62, in render_to_string return template.render(context, request) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\backends\django.py", line 61, in render return self.template.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 171, in render return self._render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 163, in _render return self.nodelist.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 937, in render bit = node.render_annotated(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 904, in render_annotated return self.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\loader_tags.py", line 150, in render return compiled_parent._render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 163, in _render return self.nodelist.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 937, in render bit = node.render_annotated(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 904, in render_annotated return self.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\loader_tags.py", line 62, in render result = block.nodelist.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 937, in render bit = node.render_annotated(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 904, in render_annotated return self.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\loader_tags.py", line 62, in render result = block.nodelist.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 937, in render bit = node.render_annotated(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\base.py", line 904, in render_annotated return self.render(context) File "D:\IDE\Python\Anaconda\lib\site-packages\django\template\defaulttags.py", line 442, in render url = reverse(view_name, args=args, kwargs=kwargs, current_app=current_app) File "D:\IDE\Python\Anaconda\lib\site-packages\django\urls\base.py", line 90, in reverse return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)) File "D:\IDE\Python\Anaconda\lib\site-packages\django\urls\resolvers.py", line 622, in _reverse_with_prefix raise NoReverseMatch(msg)django.urls.exceptions.NoReverseMatch: Reverse for 'new_topic' not found. 'new_topic' is not a valid view function or pattern name.[24/Nov/2018 22:54:00] "GET /boards/1/ HTTP/1.1" 500 169427

看起来有点乱，其实关键信息就是最后一句话：

Reverse for 'new_topic' not found . 'new_topic' is not a valid view function or pattern name. 

意思就是new_topic在反析的时候没有被找到，'new_topic' 不是一个有效的视图方法或者模式名。

浏览器报的错也贴上:

urls.py:

view.py:

我注意到其实是urls.py文件中命名空间写错了：

实际上我在view.py文件中定义的方法是new_topic，HTML模板命名也是new_topic.html，所以多加了一个s导致了错误。以后还是需要更加细心。