如何閱讀和理解django錯誤消息？

Question

我只是在學習django，好吧，對我來說django的最大問題是，如果出現問題，我會得到一個沒有任何信息的巨大追溯什麼是真的出錯了。

我實際上是遵循這個Tutorial的教程步驟。 有沒有解釋如何閱讀和理解django錯誤消息？

例子：

DoesNotExist at /admin/ 

Site matching query does not exist. 

Request Method:  GET 
Request URL: http://localhost:8080/admin/ 
Django Version:  1.4.5 
Exception Type:  DoesNotExist 
Exception Value:  

Site matching query does not exist. 

Exception Location:  /usr/lib/python2.7/dist-packages/django/db/models/query.py in get, line 366 
Python Executable: /usr/bin/python 
Python Version:  2.7.3 
Python Path:  

['/home/ps/src/python/django', 
'/usr/lib/python2.7', 
'/usr/lib/python2.7/plat-linux2', 
'/usr/lib/python2.7/lib-tk', 
'/usr/lib/python2.7/lib-old', 
'/usr/lib/python2.7/lib-dynload', 
'/usr/local/lib/python2.7/dist-packages', 
'/usr/lib/python2.7/dist-packages', 
'/usr/lib/python2.7/dist-packages/PIL', 
'/usr/lib/pymodules/python2.7/gtk-2.0', 
'/usr/lib/python2.7/dist-packages/gst-0.10', 
'/usr/lib/python2.7/dist-packages/gtk-2.0', 
'/usr/lib/pymodules/python2.7'] 

Server time: So, 27 Okt 2013 19:32:52 +0100 


Traceback: 
File "/usr/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response 
    111.       response = callback(request, *callback_args, **callback_kwargs) 
File "/usr/lib/python2.7/dist-packages/django/contrib/admin/sites.py" in wrapper 
    213.     return self.admin_view(view, cacheable)(*args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view 
    91.      response = view_func(request, *args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func 
    89.   response = view_func(request, *args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/contrib/admin/sites.py" in inner 
    195.     return self.login(request) 
File "/usr/lib/python2.7/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func 
    89.   response = view_func(request, *args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/contrib/admin/sites.py" in login 
    326.   return login(request, **defaults) 
File "/usr/lib/python2.7/dist-packages/django/views/decorators/debug.py" in sensitive_post_parameters_wrapper 
    69.    return view(request, *args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view 
    91.      response = view_func(request, *args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func 
    89.   response = view_func(request, *args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/contrib/auth/views.py" in login 
    53.  current_site = get_current_site(request) 
File "/usr/lib/python2.7/dist-packages/django/contrib/sites/models.py" in get_current_site 
    92.   current_site = Site.objects.get_current() 
File "/usr/lib/python2.7/dist-packages/django/contrib/sites/models.py" in get_current 
    25.    current_site = self.get(pk=sid) 
File "/usr/lib/python2.7/dist-packages/django/db/models/manager.py" in get 
    131.   return self.get_query_set().get(*args, **kwargs) 
File "/usr/lib/python2.7/dist-packages/django/db/models/query.py" in get 
    366.      % self.model._meta.object_name) 

Exception Type: DoesNotExist at /admin/ 
Exception Value: Site matching query does not exist. 

這是什麼東西要去嘗試告訴我？ 「/ admin /」中的「DoesNotExist」是什麼？關於「DoesNotExists」的描述僅僅告訴：「一個對象不存在」。

管理員界面肯定是之前的工作，但是我剛剛打在我的應用程序裏面對我的模型，但是從settings.py從我的項目，我會得到的消息刪除我在INSTALLED_APPS的應用程序，甚至後。 我的應用程序本身似乎工作，但管理界面沒有。

現在，谷歌搜索後，我發現我必須註釋掉「django.contrib.sites」後，一切正常。但我不認爲這將是django的方式：每次發生錯誤時，轉到谷歌，傳遞令人困惑的消息，並通過嘗試錯誤找到哪些答案符合我的問題。

我想真正理解什麼是django/python講述什麼是「真正」的問題，而不僅僅是「django深處的錯誤17」。

任何想法如何「讀取」此錯誤消息？

Answer 1

您應該將DEBUG設置爲True。然後你會得到更多的信息錯誤信息，並在回溯中的每個點上使用代碼上下文和局部變量。

就你而言，你缺少Site表（來自django.contrib.sites）中的一個條目，在運行manage.py syncdb時應該創建該條目。