Django INSTALLED_APPS 'polls' vs 'polls.apps.PollsConfig' - django

Question

In every youtube tutorial I'v seen people simply add "app_name" to INSTALLED_APPS list.
Yesterday I started Official Django Tutorial and they suggest "app_name.apps.App_nameConf" notations.
Im guessing official way is a better way and it's not hard to memorize additional syntax, I just wanna be sure. Because stuff works ether way.
Please give me a simple, easy to understand answer so even I could get it. Thanks!

Answer 1

You are right, following official way is a proper way, since the created video tutorials or third party blogs may refer to the older version of the django and such way is deprecated now.
Good luck in your beginnings!

Answer 2

In INSTALLED_APPS one can specify all apps used in this django project app.
However, you can create multiple apps in one project. By default this would result in separate directories name in root project directory.
As all apps are in root project directory - this allows to specify only (their) directory name in INSTALLED_APPS.
On the other hand, we can specify full path to project sub-app AppConfig, not relying on auto-discovering / that sub-app is located in root project directory etc.
Multiple apps in one project?
Yes, multiple apps of one project are usually tightly coupled to this specific project and cannot be used outside of it.
The main idea is separation of concerns - to split the logic into separate sections, each responsible for some part of project app.
When your app starts growing, more different logic is being added to it, models.py / views.py / forms.py etc starts growing, making it difficult to read and understand project structure as a whole.
Even in small project - separating into sub-apps may be very helpful in terms of organizing things.
There are different styles of how to organize your django app, like where should sub-apps directories be located (i.e. in root directory, or in sub-directory with project name), and apps and settings directories can be located not in root project directory. In such cases being able to specify path directly to AppConfig class is nice and also more explicit, which is better than implicit.
default_app_config is mostly used in reusable apps - apps intended to be distributed and used by other people - published to pypi. This allows just add their name in INSTALLED_APPS, not full path to their AppConfig.
You should not use it in your project unless you know that you need it.

Answer 3

The polls.apps.PollsConfig is the newer, more explicit way, and it better allows multiple configurations of the same app.
The reason why polls works is that polls/__init__.py likely has a
default_app_config = 'polls.apps.PollsConfig'
line.

Answer 4

You have to activate your model, and Django needs to know that you have your app installed.
So in settings.py you need to add 'polls.apps.PollsConfig' in INSTALLED_APPS topic because in your app.py file you have likely defined a class PollsConfig:
In settings.py
INSTALLED_APPS = [
'polls.apps.PollsConfig,
'django.contrib.admin',
'<other app...>',
]
In apps.py
class PollsConfig(AppConfig)
name = 'polls'