NoReverseMatch at /blog/ Reverse for 'blog.views.blogpost' not found. 'blog.views.blogpost' is not a

错误：

NoReverseMatch at /blog/Reverse for 'blog.views.blogpost' not found. 'blog.views.blogpost' is not a valid view function or pattern name.Request Method: GETRequest URL:    http://127.0.0.1:8000/blog/Django Version: 1.11.1Exception Type: NoReverseMatchException Value:    Reverse for 'blog.views.blogpost' not found. 'blog.views.blogpost' is not a valid view function or pattern name.

解决措施：

reverse()这又是啥？Django官方文档之Reverse

 return reverse('blog.views.blogpost',                       kwargs={'slug': self.slug, 'post_id': self.id})

reverse()介绍，reverse()用于产生url的最终形式。例如我点开文章，他会生成一大串一大串的 url地址。 类似这样的，http:/blog.csdn.net/weixin_36571185/article/details/73715296。
生成的url最终去了哪里呢？

    #这里面我用到了url反向解析。    def get_absolute_url(self):        return reverse(blog.views.blogpost,                       kwargs={'slug': self.slug, 'post_id': self.id})

最终，他出现在这里》》》》

reverse()用法：

model.py

     def get_absolute_url(self):        return reverse('blogposts'# 要么用昵称blogposts，要么用视图全称                       kwargs={'slug': self.slug, 'post_id': self.id})

    def get_absolute_url(self):        return reverse(blog.views.blogpost,#这是视图全称。                       kwargs={'slug': self.slug, 'post_id': self.id})

url.py

    url(r'^(?P<slug>[-\w\d]+),(?P<post_id>\d+)/$'views.blogpost,name='blogposts'),

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Blog.objects.exclude()是个什么玩意呢？
exclude()是过滤器，相当于sql语句里的where。用来做条件判断的。初次之外还有all(),fillter()。他们返回的都是一个查询集Queryset

filter(**kwargs)
Returns a new QuerySet containing objects that match the given lookup parameters.

exclude(**kwargs)
Returns a new QuerySet containing objects that do not match the given lookupparameters. Thelookup parameters (**kwargs in the above function definitions) should be in the format described in Field lookups below.