title: Filtering querysets for nested models
body: <p>I'm making a News App API and I want to create an APIView with comments for a speicific Post that also lets users posting comments for the specific post.</p>
  
  <p>These are my models (simplified):</p>
  
  <p>Post:</p>
  
  <pre><code>class Post(models.Model):
      title = models.CharField(max_length=250)
      text = models.TextField()
  </code></pre>
  
  <p>Comment:</p>
  
  <pre><code>class Comment(models.Model):
      post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name='comments')
      author = models.CharField(max_length=200)
      text = models.TextField()
  </code></pre>
  
  <p>And view:</p>
  
  <pre><code>class CommentList(generics.ListCreateAPIView):
      queryset = Comment.objects.filter(post=???)  
      serializer_class = CommentSerializer
  </code></pre>
  
  <p>EDIT: I would also like my url path to look like this (or similar):</p>
  
  <pre><code>urlpatterns = [
  ...
      path('posts/&lt;int:pk&gt;/comments/', CommentList.as_view())
  ] 
  </code></pre>
  
  <p>My questions:</p>
  
  <ol>
  <li>How do I create a list of comments for an instance of Post?</li>
  <li>Is it the correct approach or should I try something else?</li>
  </ol>