Django model "doesn't declare an explicit app_label"

Are you missing putting in your application name into the settings file? The myAppNameConfig is the default class generated at apps.py by the .manage.py createapp myAppName command. Where myAppName is the name of your app.

settings.py

INSTALLED_APPS = [
'myAppName.apps.myAppNameConfig',
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
]

This way, the settings file finds out what you want to call your application. You can change how it looks later in the apps.py file by adding the following code in

myAppName/apps.py

class myAppNameConfig(AppConfig):
    name = 'myAppName'
    verbose_name = 'A Much Better Name'

I had exactly the same error when running tests with PyCharm. I've fixed it by explicitly setting DJANGO_SETTINGS_MODULE environment variable. If you're using PyCharm, just hit Edit Configurations button and choose Environment Variables.

Set the variable to your_project_name.settings and that should fix the thing.

It seems like this error occurs, because PyCharm runs tests with its own manage.py.

I got this one when I used ./manage.py shell then I accidentally imported from the root project level directory

# don't do this
from project.someapp.someModule import something_using_a_model
# do this
from someapp.someModule import something_using_a_model

something_using_a_model()

as a noob using Python3 ,I find it might be an import error instead of a Django error

wrong:

from someModule import someClass

right:

from .someModule import someClass

this happens a few days ago but I really can't reproduce it...I think only people new to Django may encounter this.here's what I remember:

try to register a model in admin.py:

from django.contrib import admin
from user import User
admin.site.register(User)

try to run server, error looks like this

some lines...
File "/path/to/admin.py" ,line 6
tell you there is an import error
some lines...
Model class django.contrib.contenttypes.models.ContentType doesn't declare an explicit app_label

change user to .user ,problem solved