What could be wrong here (small code in the topic)?

Question

Django

Answer 1

It seems you missed
Then you declare a variable post
Here is an example: tutorial.djangogirls.org/ru/django_forms/index.html

Answer 2

Just change post to form

Answer 3

The post variable does not exist. You first need to define it, and only then save or add new parameters.
For example after if:
post = form

Answer 4

well, it's not just necessary to change post to form. there you need to understand what is going on. The author doesn't seem to understand. for example, if the form is not valid, what will happen to you? Or is this the topic of the next question?