如何覆盖Django中安装的应用程序中定义的模型？

Is it possible to redefine a model used in an INSTALLED_APP without modifying the app in question? For example, django-basic-blog has a Post model which I would like to add a field to. I could edit django-basic-blog directly but for code portability I'd like to build on top of it. I don't want to subclass as I want to preserve all existing references to the Post model. Thanks in advance!Is it possible to redefine a model used in an I