Python 在 Django 1.8 或更高版本中填充时出现“模型尚未加载”错误

"Models aren't loaded yet" error while populating in Django 1.8 or later

提问by Atul tyagi

I am using this code to populate my database:

我正在使用此代码填充我的数据库：

import os
def populate():
    python_cat = add_cat('Python')

    add_page(cat=python_cat, 
    title="Official Python Tutorial",
    url="http://docs.python.org/2/tutorial/")

    add_page(cat=python_cat,
    title="How to Think like a Computer Scientist",
    url="http://www.greenteapress.com/thinkpython/")

    add_page(cat=python_cat,
    title="Learn Python in 10 minutes",
    url="http://www.korokithakis.net/tutorials/python/")

    django_cat = add_cat(name="Django")

    add_page(cat=django_cat,
    title="Official Django Tutorial",
    url="http://djangoproject.com/en/1.5/intro/tutorial01/")

    add_page(cat=django_cat,
    title="Django Rocks",
    url="http://www.djangorocks.com/")

    add_page(cat=django_cat,
    title="How to Tango with Django",
    url="htttp://www.tangowithdjango.com/")

    frame_cat = add_cat(name="Other Frameworks")

    add_page(cat=frame_cat, 
    title="Bottle",
    url="http://bottlepy.org/docs/dev/")

    add_page(cat=frame_cat, 
    title="Flask",
    url="http://flask.pocoo.org")

    # Print out what we have added to the user. 
    for c in Category.objects.all():
        for p in Page.objects.filter(category=c):
            print "- {0} - {1}".format(str(c), str(p))

def add_page(cat, title, url, views=0):
    p = Page.objects.get_or_create(category=cat, title=title, url=url, views=views)[0]
    return p

def add_cat(name):
    c = Category.objects.get_or_create(name=name)
    return c

if __name__ == '__main__':
    print "Starting Rango population script..."
    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'p.settings')
    from rango.models import Category, Page
    populate()

On running

正在运行

python c:\python27\p\populate_rango.py

It gives the error:

它给出了错误：

Staring Rango population script...
Traceback (most recent call last):
File "c:\python27\p\populate_rango.py", line 59, in <module>
populate()
File "c:\python27\p\populate_rango.py", line 4, in populate
python_cat = add_cat('Python')
File "c:\python27\p\populate_rango.py", line 52, in add_cat
c = Category.objects.get_or_create(name=name)
File "C:\Python27\Lib\site-packages\django\db\models\manager.py", li
manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "C:\Python27\Lib\site-packages\django\db\models\query.py", line
et_or_create
return self.get(**lookup), False
File "C:\Python27\Lib\site-packages\django\db\models\query.py", line
clone = self.filter(*args, **kwargs)
File "C:\Python27\Lib\site-packages\django\db\models\query.py", line
ilter
return self._filter_or_exclude(False, *args, **kwargs)
File "C:\Python27\Lib\site-packages\django\db\models\query.py", line
filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "C:\Python27\Lib\site-packages\django\db\models\sql\query.py",
in add_q
clause, require_inner = self._add_q(where_part, self.used_aliases)
File "C:\Python27\Lib\site-packages\django\db\models\sql\query.py",
in _add_q
current_negated=current_negated, connector=connector)
File "C:\Python27\Lib\site-packages\django\db\models\sql\query.py",
in build_filter
lookups, parts, reffed_aggregate = self.solve_lookup_type(arg)
File "C:\Python27\Lib\site-packages\django\db\models\sql\query.py",
in solve_lookup_type
_, field, _, lookup_parts = self.names_to_path(lookup_splitted, se
a())
File "C:\Python27\Lib\site-packages\django\db\models\sql\query.py",
in names_to_path
field, model, direct, m2m = opts.get_field_by_name(name)
File "C:\Python27\Lib\site-packages\django\db\models\options.py", li
get_field_by_name
cache = self.init_name_map()
File "C:\Python27\Lib\site-packages\django\db\models\options.py", li
init_name_map
for f, model in self.get_all_related_m2m_objects_with_model():
File "C:\Python27\Lib\site-packages\django\db\models\options.py", li
get_all_related_m2m_objects_with_model
cache = self._fill_related_many_to_many_cache()
File "C:\Python27\Lib\site-packages\django\db\models\options.py", li
_fill_related_many_to_many_cache
for klass in self.apps.get_models():
File "C:\Python27\Lib\site-packages\django\utils\lru_cache.py", line
rapper
result = user_function(*args, **kwds)
File "C:\Python27\Lib\site-packages\django\apps\registry.py", line 1
_models
*self.check_models_ready()
File "C:\Python27\Lib\site-packages\django\apps\registry.py", line 1
ck_models_ready
raise AppRegistryNotReady("Models aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.*

Rest of my files are ok but getting this error. I am following the tutorial from Tango with Djangobook but as the book refers to Django 1.5.4 and i am using Django 1.8, so can anyone help me here?

我的其余文件没问题，但出现此错误。我正在使用 Django书学习Tango的教程，但由于该书指的是 Django 1.5.4，而我使用的是 Django 1.8，所以有人可以在这里帮助我吗？

采纳答案by pdw

I had the same exception with Django 1.7rc2. The solution was to add these lines at the beginning of my program:

我对 Django 1.7rc2 也有同样的例外。解决方案是在我的程序开头添加这些行：

import django
django.setup()

Update: This is now documented for Django 1.8.

更新：现在已为 Django 1.8 记录了这一点。

回答by Nick Spacek

We were getting this error. Our project started with Django 1.4, we went to 1.5 and then to 1.7. Our wsgi.py looked like this:

我们收到了这个错误。我们的项目从 Django 1.4 开始，然后是 1.5，然后是 1.7。我们的 wsgi.py 看起来像这样：

import os
import sys

from django.core.handlers.wsgi import WSGIHandler

os.environ['DJANGO_SETTINGS_MODULE'] = 'myapp.settings'
application = WSGIHandler()

When I updated to the 1.7 style WSGI handler:

当我更新到 1.7 样式的 WSGI 处理程序时：

import os
import sys

from django.core.wsgi import get_wsgi_application

os.environ['DJANGO_SETTINGS_MODULE'] = 'myapp.settings'
application = get_wsgi_application()

Everything works now.

现在一切正常。

回答by novice

well for django 1.9.x :

适用于 django 1.9.x ：

populate_rango.py:

populate_rango.py:

import os
import sys

from django.core.wsgi import get_wsgi_application

os.environ['DJANGO_SETTINGS_MODULE'] = 'tango_with_django_project.settings'
application = get_wsgi_application()

def populate():
    python_cat = add_cat('Python')

    add_page(cat=python_cat,
         title="Official Python Tutorial",
         url="http://docs.python.org/2/tutorial/")

    add_page(cat=python_cat,
        title="How to Think like a Computer Scientist",
        url="http://www.greenteapress.com/thinkpython/")

    add_page(cat=python_cat,
        title="Learn Python in 10 Minutes",
        url="http://www.korokithakis.net/tutorials/python/")

    django_cat = add_cat("Django")

    add_page(cat=django_cat,
        title="Official Django Tutorial",
        url="https://docs.djangoproject.com/en/1.5/intro/tutorial01/")

    add_page(cat=django_cat,
        title="Django Rocks",
        url="http://www.djangorocks.com/")

    add_page(cat=django_cat,
        title="How to Tango with Django",
        url="http://www.tangowithdjango.com/")

    frame_cat = add_cat("Other Frameworks")

    add_page(cat=frame_cat,
        title="Bottle",
        url="http://bottlepy.org/docs/dev/")

    add_page(cat=frame_cat,
        title="Flask",
        url="http://flask.pocoo.org")

    #Print out what we have added to the user.
    for c in Category.objects.all():
        for p in Page.objects.filter(category=c):
            print ("- {0} - {1}".format(str(c), str(p)))

def add_page(cat, title, url, views=0):
    p = Page.objects.get_or_create(category=cat, title=title, url=url, views=views)[0]
    return p

def add_cat(name):
    c = Category.objects.get_or_create(name=name)[0]
    return c

# Start execution here!
if __name__ == '__main__':
    print ("Starting Rango population script...")
    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'tango_with_django_project.settings')
    from rango.models import Category, Page
    populate()