在 Django 1.8 或更高版本中填充时出现“模型尚未加载”错误

Posted 2023-02-24

【中文标题】在 Django 1.8 或更高版本中填充时出现“模型尚未加载”错误

【英文标题】："Models aren't loaded yet" error while populating in Django 1.8 or later

【发布时间】：2014-10-04 08:40:26

【问题描述】：

我正在使用此代码来填充我的数据库：

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()

正在运行

python c:\python27\p\populate_rango.py

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.*

我的其余文件都可以，但出现此错误。我正在遵循 Tango with Django 书中的教程，但由于这本书指的是 Django 1.5.4，而我使用的是 Django 1.8，所以任何人都可以在这里帮助我吗？

【问题讨论】：

没有理由使用“Django 1.8”。 1.7还没有出来。您应该使用稳定版 1.6 或可能 1.7 候选版本。

我在 Django 1.7 final 中遇到了这个问题。接受的答案修复了它。

【参考方案1】：

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()

更新：This is now documented for Django 1.8.

【讨论】：

如果你在 Django 执行 python manage.py 后遇到这个错误，试试这个：***.com/q/25537905/540717

即使另一个模型已经在该包中工作，但后来我导入另一个模型突然发生加载尚未。你的答案解决了..谢谢..

对于unittest 和run.py 脚本也非常有用！ （可能在设置 PYTHONPATH 之后。）

在设置 DJANGO_SETTINGS_MODULE 的环境变量后添加。否则会产生配置不正确的错误。

docs.djangoproject.com/en/1.8/topics/settings/…docs.djangoproject.com/en/1.8/topics/settings/…的 setup() 的 Django 文档

【参考方案2】：

我们遇到了这个错误。我们的项目从 Django 1.4 开始，我们到 1.5，然后到 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()

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()

现在一切正常。

【讨论】：

当我升级到 django 1.8 时为我工作。谢谢+1

【参考方案3】：

非常适合 django 1.9.x：

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()