What and how to test with unit tests in django?

Question

Django

Hello.
I am now bringing my project (thematic portal) to the stage of "checking everything so that everything works, correcting errors, polishing". And smart books tell me that I should write unit tests. All my acquaintance with them was previously limited to lectures from the guys from jetbrains (and even then in Java). So the questions are:
1) Is it necessary to write unit tests in django?
2) If you write, then what needs to be covered, and what can be missed.
3) What tools are used to write unit tests for django.
If any of my questions seem idiotic, please let me know as well.

Answer 1

chimera.labs.oreilly.com/books/1234000000754
1 yes
2
you need to test everything
don't need to test django functionality
don't need to test constants
3
Selenium + unittest https://docs.djangoproject.com/en/1.9/topics/testi...