Как написать тесты модели пропбера в python с django?

Question

Для текущего школьного проекта я и мои друзья разработали небольшое приложение для поиска книг в Python с Django. Фактически мы почти закончили, но есть проблемы с написанием тестов. Будем рады услышать, как вы подойдете к тестам. Они могут быть максимально простыми.

book.py:

from django.db import models
import pdb


class Book:

    def __init__(self, book_element):
        self.book_information = self.create_book(book_element)

        # some instance variabless are missing try fixing it maybe use forms

    def create_book(self, book_element):
        info = book_element["volumeInfo"]

        title = info.get("title")
        publisher = info.get("publisher, Nicht vorhanden")
        author = info.get("authors, Nicht vorhanden.")

        imageTrue = info["readingModes"].get("image")

        if imageTrue == True:
            image = info["imageLinks"].get("thumbnail")
        else:
            image = "Nicht vorhanden"

        published_Date = info.get("publishedDate, Nicht vorhanden.")
        page_Count = info.get("pageCount, Nicht vorhanden.")
        categorie = info.get("categories, Nicht vorhanden")

        book_information = {
            "title": title,
            "author": author,
            "publisher": publisher,
            "publishedDate": published_Date,
            "pageCount": page_Count,
            "image": image,
            "categorie": categorie
        }

        return book_information

book_api.py:

from django.db import models
from .book import Book
import requests
import pdb


class Book_Api:

    def __init__(self, search):
        self.show_books = self.process_data(search)

    # try using private methods and what about class methods

    def process_data(self, search):
        json_respose = self.__fetch_data(search)
        books_list = []
        for book in json_respose["items"]:
            book_obj = Book(book)
            books_list.append(book_obj)

        return books_list

    def __fetch_data(self, book_search):
        key = "AIzaSyA02bYtu7X4pdwRlmOlp0HrouGGwue0qaY"
        filter = "partial"
        printType = "books"
        language = "de"
        url = "https://www.googleapis.com/books/v1/volumes?q=intitle:{}&filter={}&printType={}&maxResults=10&projection=full&langRestrict={}&keyes&key={}"
        data = requests.get(url.format(
            book_search, filter, printType, language, key)).json()
        return data