Install

First install roughage: pip install django-roughage

Assume that your app/models.py looks like this

class Book(models.Model):

    title = models.CharField(max_length=255)

class BookReport(models.Model):

    book = models.ForeignKey(Book)
    grade = models.IntegerField()

Defining seeds.py

Then you define a seeds.py like the following:

from roughage import Seed
from app.models import Book, BookReport

class BookSeed(Seed):

    model = Book

    def querysets(self):
        return [
            Book.objects.filter(id__lt=3)
        ]

class BookReportSeed(Seed):

    model = BookReport

    def trim_app__book(self, queryset):
        return queryset[:2]

Planting and Reaping

Then run

$ ./manage.py plant --seeds=seeds.py --file=dev_dump.json

dev_dump.json will contain all books with id < 3 and the first two book reports attached to those books.

You can now import this into another database with

$ ./manage.py reap dev_dump.json