django python manage.py runserver RuntimeError: Settings already configured

Question

我对 Django 和 Python 很陌生。我的环境是Win7和Python3.4。现在按照 Django 官网中的教程构建一个 web 应用程序。起初，一切都运行良好，输出都是预期和正确的。但是今天当我重新运行命令"python manage.py runserver" 时，它给了我非常奇怪的错误信息如下。请帮助，非常感谢！

$ python manage.py runserver 
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 312, in execute
    django.setup()
  File "C:\Python34\lib\site-packages\django\__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Python34\lib\site-packages\django\apps\registry.py", line 115, in populate
    app_config.ready()
  File "C:\Python34\lib\site-packages\django\contrib\admin\apps.py", line 22, in ready
    self.module.autodiscover()
  File "C:\Python34\lib\site-packages\django\contrib\admin\__init__.py", line 24, in autodiscover
    autodiscover_modules('admin', register_to=site)
  File "C:\Python34\lib\site-packages\django\utils\module_loading.py", line 74, in autodiscover_modules
    import_module('%s.%s' % (app_config.name, module_to_search))
  File "C:\Python34\lib\importlib\__init__.py", line 109, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 2254, in _gcd_import
  File "<frozen importlib._bootstrap>", line 2237, in _find_and_load
  File "<frozen importlib._bootstrap>", line 2226, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1129, in _exec
  File "<frozen importlib._bootstrap>", line 1471, in exec_module
  File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
  File "D:0\My Cloud Software Eclipse PythonTDD_Django\tdd_django\mysite\polls\admin.py", line 34, in <module>
    settings.configure()
  File "C:\Python34\lib\site-packages\django\conf\__init__.py", line 58, in configure
    raise RuntimeError('Settings already configured.')
RuntimeError: Settings already configured.

Answer 1

来自docs：

If you set DJANGO_SETTINGS_MODULE, access settings values somehow, then call configure(), Django will raise a RuntimeError indicating that settings have already been configured.

Also, it’s an error to call configure() more than once, or to call configure() after any setting has been accessed.

问题是，当您在 mysite.polls.admin 中调用 settings.configure() 时，设置已经配置完毕。抑制错误的一种选择是添加一些完整性检查：

if not settings.configured:
    settings.configure()

django python manage.py runserver RuntimeError: Settings already configured

django python manage.py runserver RuntimeError: Settings already configured

python

django

django-settings

django-dev-server