What's the best way to have value object using Django data model?
Once I dropped the notion of Value Object carried over from JAVA background,
and started to focus on what I really want, I found a simple way to get
this: to custom build a dictionary in views.py, based on the data
coming back from related models.   And then add each dictionary to 
a list bucket and use json dumps prior to rendering JSON feeds.
Our Django data model objects are nicely mapped to database tables.  We want a way to package data from two or more tables into a customized structure, so that we can easily serve it up as JSON feed, having all the attributes and is in the desired format.
It is kind of like "value objects" (POJO) in other environment such as JAVA, providing convenience when packaging and displaying data.   They should be transient and not persisted in database; yet at the same time contains all the necessary attributes and in the original data types (in Django world this is called "_meta").   
Appreciate your reply and suggestions.