1.正常安装、正常导入、正常在模型中使用。

2.在python manage.py syncdb时没有对tagging_tag表的描述。

3.提示异常信息为：

OperationalError at /admin/coltrane/entry/add/

 no such table: tagging_tag

     no such table: tagging_tag
    

>>> import tagging
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "D:\Python26\lib\site-packages\tagging\__init__.py", line 3, in <module>
    from tagging.managers import ModelTaggedItemManager, TagDescriptor
  File "D:\Python26\lib\site-packages\tagging\managers.py", line 5, in <module>
    from django.contrib.contenttypes.models import ContentType
  File "D:\Python26\lib\site-packages\django\contrib\contenttypes\models.py", li
ne 1, in <module>
    from django.db import models
  File "D:\Python26\lib\site-packages\django\db\__init__.py", line 9, in <module
>
    if not settings.DATABASE_ENGINE:
  File "D:\Python26\lib\site-packages\django\utils\functional.py", line 269, in
__getattr__
    self._setup()
  File "D:\Python26\lib\site-packages\django\conf\__init__.py", line 37, in _set
up
    raise ImportError("Settings cannot be imported, because environment variable
 %s is undefined." % ENVIRONMENT_VARIABLE)
ImportError: Settings cannot be imported, because environment variable DJANGO_SE
TTINGS_MODULE is undefined.

http://docs.djangoproject.com/en/dev/ref/templates/api/#configuring-the-template-system-in-standalone-mode

http://hi.baidu.com/withjourney/blog/item/22f072508ca755020cf3e3ff.html

做个记号，再研究。崩溃中……

把tag有关的行注释掉了，然后下载了个sqliteadmin把数据库表里的tags也删除了。

问题解决了：tagging作为一个app，要想应用，需要在INSTALLED_APPSS中加上。

仔细看了一下：http://hi.baidu.com/10428/blog/item/8a9eb50e5b84e5e337d1226a.html

 Using Django Tagging in your applications
 

 -----------------------------------------
 

 

 Once you've installed Django Tagging and want to use it in your Django
 

 applications, do the following:
 

 

 1. Put ``'tagging'`` in your ``INSTALLED_APPS`` setting.
 

 2. Run the command ``manage.py syncdb``.
 

 

 The ``syncdb`` command creates the necessary database tables and
 

 creates permission objects for all installed apps that need them.
 

 

 That's it!