Basic django-pytest tests

Even just learning the django and testwriting, so I need a bit of confirmation. I would like to know that the following tests are "correct" spelling of it.

test_view.py

@pytest.mark.django_db
def test_create_form(client):
    form_data = {'title': 'Test Title', 'tags': 'HTML', 'content': 'New Content for lambs'}
    response = client.post(reverse("public:create"), form_data, follow=True)
    assert b'Test Title' in response.content

@pytest.mark.django_db
def test_context_create(client):
   form_data = {'title': 'Test Title', 'tags': 'HTML', 'content': 'New Content for lambs'}
   response = client.post(reverse("public:create"), form_data)
   assert response.context['form'].cleaned_data['title'] == 'Test Title'

@pytest.mark.django_db
def test_TITLE_is_blank(client):
    form_data = {'title': '', 'tags': 'HTML', 'content': 'New Content for lambs'}
    response = client.post(reverse("public:create"), form_data)
    assert response.context['form'].cleaned_data['title'] == ''

@pytest.mark.django_db
def test_CONTENT_is_blank(client):
    form_data = {'title': 'Test Title', 'tags': 'HTML', 'content': ''}
    response = client.post(reverse("public:create"), form_data)
    assert response.context['form'].cleaned_data['content'] == ''

@pytest.mark.django_db
def test_CONTENT_and_TITLE_is_blank(client):
    form_data = {'title': '', 'tags': 'HTML', 'content': ''}
    response = client.post(reverse("public:create"), form_data)
    assert (not response.context['form'].is_valid())

forms.py

class PostForm(ModelForm):

    def __init__(self, *args, **kwargs):
        super(PostForm, self).__init__(*args,**kwargs)

        self.fields['title'].required = False
        self.fields['content'].required = False

    class Meta:
        model = Post
        fields = ['title', 'tags', 'content']

    def clean(self):
        form_data = self.cleaned_data

        if (form_data['title'] is not "") or (form_data['content'] is not ""):
            return form_data
        else:
           self._errors["title"] = ["Two field is empty"]


    def save(self, *args, **kwargs):
        instance = super(PostForm, self).save(commit=False)
        instance.slug = slugify(instance.title)
        instance.save()

        return instance

This is the model

class Post(models.Model):
    title = models.CharField(max_length=200)
    tags = models.ManyToManyField(Tags)
    slug = models.SlugField(max_length=200, blank=True)
    creation_date = models.DateTimeField(auto_now_add=True)
    modify_date = models.DateTimeField(auto_now=True)
    content = models.TextField()

Thank you for your help and advice.