django.core.exceptions.ImproperlyConfigured: Requested setting DEFAULT_INDEX_TABLESPACE的解决办法

在python的开发中，遇到了这个错误： 
django.core.exceptions.ImproperlyConfigured: Requested setting DEFAULT_INDEX_TABLESPACE, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings. 
解决方法如下： 
在项目目录打开打开命令行，键入python manage.py shell进入交互模式，执行下列代码即可：

import os,django
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project_name.settings")# project_name 项目名称
django.setup()