尝试导入python模块时的疯狂行为

我有一些django webapp的问题，我想用Apache mod-wsgi进行部署，我已将它们追溯到这一行（缺少django-tagging模块）：

[Wed Feb 20 13:08:42 2013] [error] [client 172.19.130.50] ImportError: No module named tagging

现在，当我尝试以root身份和apache用户运行pip-python（我使用CENTOS 6）时，这是我的输出：

[root@app1 site-packages]# pip-python freeze | grep tag
django-tagging==0.3.1
django-taggit==0.9.3

已安装标记...

[root@app1 site-packages]# sudo -u apache pip-python freeze | grep tag
django-tagging==0.3.1
django-taggit==0.9.3

Apache用户也这么说！

[root@app1 /]# python
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import tagging
>>>

Ok root可以导入标记！

[root@app1 /]# sudo -u apache python
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import tagging
Traceback (most recent call last):
  File "", line 1, in 
ImportError: No module named tagging
>>>

但是apache用户不能!!!!!我该怎么做才能做到这一点????

我已经对/usr/lib/python2.6/site-packages/对django-tagging的所有权利进行了双倍和三倍检查，它们与我的其他包相同 .

Update 1: 我真的不记得我是如何安装django-tagging模块的 - 但可能是root用户，因为apache无法全局安装模块！

Update 2: 这里's the output of martijn-pieters'的建议：

[root@app1 /]# sudo -u apache python -c 'import sys; print sys.path'
['', '/usr/lib64/python2.6/site-packages/Twisted-12.1.0-py2.6-linux-x86_64.egg', '/usr/lib/python2.6/site-packages/django_cas-2.1.1-py2.6.egg', '/usr/lib64/python26.zip', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info']
[root@app1 /]# python -c 'import sys; print sys.path'
['', '/usr/lib64/python2.6/site-packages/Twisted-12.1.0-py2.6-linux-x86_64.egg', '/usr/lib/python2.6/site-packages/django_cas-2.1.1-py2.6.egg', '/usr/lib64/python26.zip', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info']
[root@app1 /]# sudo -u apache head `which pip-python`
#!/usr/bin/python
# EASY-INSTALL-ENTRY-SCRIPT: 'pip==0.8','console_scripts','pip'
__requires__ = 'pip==0.8'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
    sys.exit(
        load_entry_point('pip==0.8', 'console_scripts', 'pip')()
    )
[root@app1 /]# head `which pip-python`
#!/usr/bin/python
# EASY-INSTALL-ENTRY-SCRIPT: 'pip==0.8','console_scripts','pip'
__requires__ = 'pip==0.8'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
    sys.exit(
        load_entry_point('pip==0.8', 'console_scripts', 'pip')()
    )

完全一样:(

Update 3: 是的，apache用户可以加载其他模块：

[root@app1 /]# sudo -u apache python
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> import twisted
>>> import cairo

Update 4: 我讨厌自己 . 问题是/usr/lib/python2.6/site-packages/tagging/目录的访问权限！他们是drw-r - r--（644）而不是正确的drwxr-xr-x（755）所以apache用户无法进入目录:(

现在一切正常，感谢所有的帮助！