python – Django 1.9：在`django.setup()`中我应该避免导入模型吗？

将我的应用程序移植到django 1.9,我得到了可怕的django.core.exceptions.AppRegistryNotReady：尚未加载应用程序

基本上我的堆栈跟踪是：

  manage.py
    execute_from_command_line(sys.argv)
  django/core/management:352, in execute_from_command_line
    utility.execute()
  django/core/management/__init__.py:326, in execute
    django.setup()
  django/__init__.py:18, in setup
    apps.populate(settings.INSTALLED_APPS)
  django/apps/registry.py:85, in populate
    app_config = AppConfig.create(entry)
  django/apps/config.py:90, in create
    module = import_module(entry)
  python2.7/importlib/__init__.py:37, in import_module
    __import__(name)
  myapp/mylib/__init__.py:52, in <module>
    from django.contrib.contenttypes.models import ContentType   #<= The important part
  django/contrib/contenttypes/models.py:159, in <module>
    class ContentType(models.Model):
  django/db/models/base.py:94, in __new__
    app_config = apps.get_containing_app_config(module)
  django/apps/registry.p:239, in get_containing_app_config
    self.check_apps_ready()
  django/apps/registry.py:124, in check_apps_ready
    raise AppRegistryNotReady("Apps aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.

我的主要问题在这里：

我应该在我的django应用程序的__init__.py中导入我的模型吗？

它似乎触发了django.models.ModelBase元类,它在创建模型之前检查应用程序是否准备就绪.

最佳答案

Should I import my models in the __init__.py of my django apps ?

不,您不得在任何已安装的应用程序的__init__.py文件中导入任何模型.这在1.9中已不再可能.

从release notes：

All models need to be defined inside an installed application or
declare an explicit app_label. Furthermore, it isn’t possible to
import them before their application is loaded. In particular, it
isn’t possible to import models inside the root package of an
application.