class Comment(models.Model):
    post = models.ForeignKey('blog.Post', on_delete=models.CASCADE, related_name='comments')
    author = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(default=timezone.now)
    approved_comment = models.BooleanField(default=False)
​
    def approve(self):
        self.approved_comment = True
        self.save()
​
    def __str__(self):
        return self.text

(myvenv) ~/djangogirls$ python manage.py makemigrations blog
Migrations for 'blog':
  0002_comment.py:
    - Create model Comment

    (myvenv) ~/djangogirls$ python manage.py migrate blog
    Operations to perform:
      Apply all migrations: blog
    Running migrations:
      Rendering model states... DONE
      Applying blog.0002_comment... OK

admin.site.register(Post)

admin.site.register(Comment)

from django.contrib import admin
from .models import Post, Comment
​
admin.site.register(Post)
admin.site.register(Comment)

<hr>
{% for comment in post.comments.all %}
    <div class="comment">
        <div class="date">{{ comment.created_date }}</div>
        <strong>{{ comment.author }}</strong>
        <p>{{ comment.text|linebreaks }}</p>
    </div>
{% empty %}
    <p>No comments here yet :(</p>
{% endfor %}

.comment {
    margin: 20px 0px 20px 20px;
}

<a href="{% url 'post_detail' pk=post.pk %}">Comments: {{ post.comments.count }}</a>

{% extends 'blog/base.html' %}
​
{% block content %}
    {% for post in posts %}
        <div class="post">
            <div class="date">
                {{ post.published_date }}
            </div>
            <h1><a href="{% url 'post_detail' pk=post.pk %}">{{ post.title }}</a></h1>
            <p>{{ post.text|linebreaksbr }}</p>
            <a href="{% url 'post_detail' pk=post.pk %}">Comments: {{ post.comments.count }}</a>
        </div>
    {% endfor %}
{% endblock content %}

class CommentForm(forms.ModelForm):
​
    class Meta:
        model = Comment
        fields = ('author', 'text',)

from .models import Post

from .models import Post, Comment

<a class="btn btn-default" href="{% url 'add_comment_to_post' pk=post.pk %}">Add comment</a>

path('post/<int:pk>/comment/', views.add_comment_to_post, name='add_comment_to_post'),

def add_comment_to_post(request, pk):
    post = get_object_or_404(Post, pk=pk)
    if request.method == "POST":
        form = CommentForm(request.POST)
        if form.is_valid():
            comment = form.save(commit=False)
            comment.post = post
            comment.save()
            return redirect('post_detail', pk=post.pk)
    else:
        form = CommentForm()
    return render(request, 'blog/add_comment_to_post.html', {'form': form})

from .forms import PostForm, CommentForm

{% extends 'blog/base.html' %}
​
{% block content %}
    <h1>New comment</h1>
    <form method="POST" class="post-form">{% csrf_token %}
        {{ form.as_p }}
        <button type="submit" class="save btn btn-default">Send</button>
    </form>
{% endblock %}

{% for comment in post.comments.all %}
    <div class="comment">
        <div class="date">{{ comment.created_date }}</div>
        <strong>{{ comment.author }}</strong>
        <p>{{ comment.text|linebreaks }}</p>
    </div>
{% empty %}
    <p>No comments here yet :(</p>
{% endfor %}

{% for comment in post.comments.all %}
    {% if user.is_authenticated or comment.approved_comment %}
    <div class="comment">
        <div class="date">
            {{ comment.created_date }}
            {% if not comment.approved_comment %}
                <a class="btn btn-default" href="{% url 'comment_remove' pk=comment.pk %}"><span class="glyphicon glyphicon-remove"></span></a>
                <a class="btn btn-default" href="{% url 'comment_approve' pk=comment.pk %}"><span class="glyphicon glyphicon-ok"></span></a>
            {% endif %}
        </div>
        <strong>{{ comment.author }}</strong>
        <p>{{ comment.text|linebreaks }}</p>
    </div>
    {% endif %}
{% empty %}
    <p>No comments here yet :(</p>
{% endfor %}

path('comment/<int:pk>/approve/', views.comment_approve, name='comment_approve'),
path('comment/<int:pk>/remove/', views.comment_remove, name='comment_remove'),

@login_required
def comment_approve(request, pk):
    comment = get_object_or_404(Comment, pk=pk)
    comment.approve()
    return redirect('post_detail', pk=comment.post.pk)
​
@login_required
def comment_remove(request, pk):
    comment = get_object_or_404(Comment, pk=pk)
    comment.delete()
    return redirect('post_detail', pk=comment.post.pk)

from .models import Post, Comment

<a href="{% url 'post_detail' pk=post.pk %}">Comments: {{ post.comments.count }}</a>

<a href="{% url 'post_detail' pk=post.pk %}">Comments: {{ post.approved_comments.count }}</a>

def approved_comments(self):
    return self.comments.filter(approved_comment=True)