Manager isn't available; User has been swapped for 'pet.Person'

Question

I\'m been using the default user model in django for quite a abit and I realize , if I need to further enhance it , I would have to create my own custom User Model in django

Answer 1

Important caveat to update the above solutions... If you're facing this kind of problem, you've probably tried various solutions around the web telling you to add AUTH_USER_MODEL = users.CustomUser to settings.py and then to add the following code to views.py forms.py and any other file that calls User:

from django.contrib.auth import get_user_model
User = get_user_model()

And then you scratch your head when you get the error:

Manager isn't available; 'auth.User' has been swapped for 'users.User'

Anytime your code references User such as:

User.objects.get()

Cause you know you already put objects = UserManager() in your custom user class (UserManager being the name of your custom manager that extends BaseUserManager).

Well as it turns out doing:

User = get_user_model() # somewhere at the top of your .py file
# followed by
User.objects.get() # in a function/method of that same file

Is NOT equivalent to:

get_user_model().objects.get() # without the need for User = get_user_model() anywhere

Perhaps not intuitive, but it turns out that that in python, executing User = get_user_model() once at the time of import does not then result in User being defined across subsequent calls (i.e. it does not turn User into a "constant" of sorts which you might expect if you're coming from a C/C++ background; meaning that the execution of User = get_user_model() occurs at the time of imports, but is then de-referenced before subsequent called to class or function/method in that file).

So to sum up, in all files that reference the User class (e.g. calling functions or variables such as User.objects.get() User.objects.all() User.DoesNotExist etc...):

# Add the following import line
from django.contrib.auth import get_user_model

# Replace all references to User with get_user_model() such as...
user = get_user_model().objects.get(pk=uid)
# instead of  user = User.objects.get(pk=uid)
# or
queryset = get_user_model().objects.all()
# instead of queryset = User.objects.all()
# etc...

Hope this helps save others some time...