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djangodjango-migrationsdjango-apps

django makemigration throw error on sub app

I created an app inside my application "inventory_management" by django-admin startapp testing The project directory is shown below where emporium_apparel is my main project and testing is my sub app

when I run python manage.py makemigrations

it gives

Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\mhashirhassan22\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "C:\Users\mhashirhassan22\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\core\management\__init__.py", line 377, in execute
    django.setup()
  File "C:\Users\mhashirhassan22\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\mhashirhassan22\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\apps\registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
  File "C:\Users\mhashirhassan22\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\apps\config.py", line 90, in create
    module = import_module(entry)
  File "C:\Users\mhashirhassan22\AppData\Local\Programs\Python\Python38-32\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 973, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'testing'

enter image description here

Solution

  • If an application is nested and can not be imported from the Python path than you must write a complete path in INSTALLED_APPS, e.g. inventory_management.testing in your case. The name of application will be only the last part, e.g. testing. That is used in default tables names and also in migrations. It is similar to "django.contrib.admin" that is in INSTALLED_APPS, but the short app name is "admin". That name must be unique in your project.

    The name "testing" seems very general and it could be a problem. If you encounter a name conflict with another packages that have an application named "testing", you can fix it by another name by advanced configuration of the project with apps module, without changing anything in any application.

    Django is more general and there is no concept of "sub application". Any application can depend on another application regardless whether it is inside its directory or not.