Django management command to generate factory-boy boilerplate factory definitions for all the models in a given app. The code is not intended to be usable right off the bat, it just provides a few sane defaults based on the structure of your models.

generate_factories.py

from django.core.management.base import BaseCommand
from django.db.models import get_models, get_app, fields
from django.db.models.fields import related


class Command(BaseCommand):
    help = """Generate factory-boy factories for the given app"""

    def handle(self, *args, **options):
        assert len(args) == 1, 'Must specify app name as first and only argument'

        app = get_app(args[0])
        models = get_models(app)
        app_label = models[0]._meta.app_label

        print("""
import factory
import datetime

import {models} as {app_label}_models

# import other requried factories here
""".format(models=app.__name__, app_label=app_label))

        needed_factories = set()
        created_factories = set()
        for model in models:
            print("""
class {model_name}Factory(factory.django.DjangoModelFactory):
    class Meta:
        model = {app_label}_models.{model_name}

""".format(app_label=app_label, model_name=model.__name__))
            for field in model._meta.fields:
                # skip fields with default values or that can be blank
                if isinstance(field, fields.AutoField):
                    continue
                if field.default != fields.NOT_PROVIDED:
                    print('    # skipped field {0} ({1}) with default value ({2})'.format(
                        field.name, field.__class__.__name__, field.default))
                    continue
                if field.blank or field.null:
                    print('    # skipped blank or nullable field {0} ({1})'.format(
                        field.name, field.__class__.__name__))
                    continue
                args = []
                model_slug = model._meta.verbose_name.replace(' ', '-')
                if field.choices:
                    cls = 'factory.fuzzy.FuzzyChoice'
                    args.append('** need choices **')
                elif isinstance(field, fields.IntegerField):
                    cls = 'factory.fuzzy.FuzzyInteger'
                    args.append('0')
                elif isinstance(field, fields.EmailField):
                    cls = 'factory.Sequence'
                    args.append('lambda n: "{0}-{1}-{{}}@example.com".format(n)'.format(
                        model_slug, field.name))
                elif isinstance(field, fields.CharField) or isinstance(field, fields.TextField):
                    cls = 'factory.Sequence'
                    args.append('lambda n: "{0}-{1}-{{}}".format(n)'.format(model_slug, field.name))
                elif isinstance(field, fields.DateTimeField):
                    cls = 'factory.fuzzy.FuzzyNaiveDateTime'
                    args.append('datetime.datetime.now() - datetime.timedelta(days=365)')
                elif isinstance(field, fields.DateField):
                    cls = 'factory.fuzzy.FuzzyDate'
                    args.append('datetime.date.today() - datetime.timedelta(days=365)')
                elif (isinstance(field, related.ForeignKey) or
                      isinstance(field, related.OneToOneField)):
                    cls = 'factory.SubFactory'
                    rel = field.rel.to.__name__
                    rel_factory = '{0}Factory'.format(rel)
                    needed_factories.add(rel_factory)
                    args.append(rel_factory)
                else:
                    cls = 'factory.UNKNOWN'
                    args.append(field.__class__.__name__)
                print('    {name} = {cls}({args})'.format(
                    name=field.name, cls=cls, args=', '.join(args)))
            created_factories.add('{model_name}Factory'.format(model_name=model.__name__))
            print('')  # two lines between class definitions
        print('# TODO: you also need to create and add imports for the '
              'following related factories: {0}'.format(
                  ', '.join(needed_factories - created_factories)))