Dropbox SDK无法导入？

导入它时，Dropbox SDK遇到了这个奇怪的问题。在服务器上，我收到错误消息

ImportError at /supplier/
No module named client
Request Method: GET
Request URL:    http://localhost:8000/supplier/
Django Version: 1.7.7
Exception Type: ImportError
Exception Value:    
No module named client
Exception Location: /home/yonk/projects/apple/supplier/dropbox_adapter.py in <module>, line 3
Python Executable:  /home/yonk/projects/apple/venv/bin/python
Python Version: 2.7.6
Python Path:    
['/home/yonk/projects/apple',
 '/home/yonk/Desktop/eclipse/plugins/org.python.pydev_3.9.2.201502050007/pysrc',
 '/home/yonk/projects/apple',
 '/home/yonk/projects/apple/venv/lib/python2.7',
 '/home/yonk/projects/apple/venv/lib/python2.7/lib-dynload',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-x86_64-linux-gnu',
 '/usr/lib/python2.7/lib-tk',
 '/home/yonk/projects/apple/venv/local/lib/python2.7/site-packages',
 '/home/yonk/projects/apple/venv/lib/python2.7/plat-x86_64-linux-gnu',
 '/home/yonk/projects/apple/venv/lib/python2.7/lib-tk',
 '/home/yonk/projects/apple/venv/lib/python2.7/lib-old']
Server time:    Sun, 5 Apr 2015 17:51:22 +0000

我的view.py文件如下所示，只需一行即可尝试导入SDK

import dropbox
#EOF

到目前为止的尝试：

• 删除该行import dropbox，错误消失，但这失败了

• 在./manage shell，我能够导入保管箱没有问题。

• 通过pip重新安装保管箱，问题仍然存在

• 运行./manage runserver以及通过WSGI服务器。两者都产生相同的错误。

• 导入其他第三方模块，例如django-facebook，没有错误