为什么是"Models aren't loaded yet"？

Question

我正在尝试使用自定义用户安装 django-registration-redux。

我已将其包含在我的 settings.py 中：

AUTH_USER_MODEL = 'app.customUser'

注册表在目录中../registration/forms.py:

from __future__ import unicode_literals


from django import forms
from django.utils.translation import ugettext_lazy as _
from django.contrib.auth.forms import UserCreationForm

from .users import UserModel, UsernameField

User = UserModel()


class RegistrationForm(UserCreationForm):

    required_css_class = 'required'
    email = forms.EmailField(label=_("E-mail"))

    class Meta:
        model = customUser
        fields = ('email')

另外，models.py有以下内容：

from __future__ import unicode_literals
from django.db import models

# Create your models here.

import datetime
import hashlib
import random
import re

from django.conf import settings
from django.core.mail import EmailMultiAlternatives
from django.db import models
from django.template import RequestContext, TemplateDoesNotExist
from django.template.loader import render_to_string
from django.utils.translation import ugettext_lazy as _
from django.utils.encoding import python_2_unicode_compatible
from django.utils.timezone import now as datetime_now
from django.utils import six

from .users import UserModel, UserModelString


from django.contrib.auth.models import BaseUserManager, AbstractBaseUser
from django.contrib.auth.admin import UserAdmin


class customUserManager(BaseUserManager):
    def create_user(self, email, password=None):
        """
        Creates and saves a User with the given email, date of
    birth and password.
        """
        if not email:
            raise ValueError('Users must have an email address')

        user = self.model(
            email=self.normalize_email(email),
        )

        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_superuser(self, email, password):
        """
        Creates and saves a superuser with the given email, date of
    birth and password.
        """
        user = self.create_user(email,
            password=password,
        )
        user.is_active = True
        user.is_admin = True
        user.save(using=self._db)
        return user

class customUser(AbstractBaseUser):
    email = models.EmailField(verbose_name='email address', max_length=255, unique=True)
    first_name = models.CharField(max_length=50, null=True)
    middle_name = models.CharField(max_length=50, null=True)
    last_name = models.CharField(max_length=50, null=True)
    is_active = models.BooleanField(default=False)
    is_admin = models.BooleanField(default=False)

    objects = customUserManager()

    USERNAME_FIELD = 'email'


class customUserAdmin(UserAdmin):
    # The forms to add and change user instances
    #form = UserChangeForm
    #add_form = RegisterationForm

class RegistrationManager(models.Manager):
    """
    """

这是回溯：

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
utility.execute()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 312, in execute
django.setup()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
apps.populate(settings.INSTALLED_APPS)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
app_config.import_models(all_models)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/apps/config.py", line 198, in import_models
self.models_module = import_module(models_module_name)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
  File "/Users/Desktop/app/sites/models.py", line 21, in <module>
from .users import UserModel, UserModelString
  File "/Users/Desktop/app/sites/users.py", line 4, in <module>
UserModel = get_user_model()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/contrib/auth/__init__.py", line 150, in get_user_model
return django_apps.get_model(settings.AUTH_USER_MODEL)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/apps/registry.py", line 199, in get_model
self.check_models_ready()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/apps/registry.py", line 131, in check_models_ready
raise AppRegistryNotReady("Models aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.

如果我在 users.py 中删除 get_user_model 中的 ()，我会收到此错误：

users.py

from django.conf import settings
from django.contrib.auth import get_user_model

UserModel = get_user_model

def UserModelString():
    try:
        return settings.AUTH_USER_MODEL
    except AttributeError:
        return 'auth.User'


def UsernameField():
    return getattr(UserModel(), 'USERNAME_FIELD', 'email')

错误：

File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/contrib/auth/__init__.py", line 155, in get_user_model
"AUTH_USER_MODEL refers to model '%s' that has not been installed" % settings.AUTH_USER_MODEL
django.core.exceptions.ImproperlyConfigured: AUTH_USER_MODEL refers to model 'app.customUser' that has not been installed

Answer 1

这里是 get_user_model 函数的文档，可能会有帮助。

Generally speaking, you should reference the User model with the AUTH_USER_MODEL setting in code that is executed at import time. get_user_model() only works once Django has imported all models.

问题出在文件 ../registration/forms.py:

User = UserModel()

UserModel 在导入时执行，这是错误的并引发异常“模型尚未加载”。在需要的地方直接在表单 methods/functions 中使用 UserModel()。看几个例子here.

希望这对您有所帮助。

为什么是"Models aren't loaded yet"？

Why are "Models aren't loaded yet"?

python

django

django-apps