formset_example.py

#!/usr/bin/env python
# -*- coding:utf-8 -*-

# Stolen from: https://mlvin.xyz/django-single-file-project.html

import datetime
import inspect
import os
import sys

from types import ModuleType

import django

from django.conf import settings
from django.urls import include, path, reverse
from django.apps import apps, AppConfig
from django.http import HttpResponse

BASE_DIR = os.path.dirname(os.path.abspath(__file__))

# The current name of the file, which will be the name of our app
APP_LABEL, _ = os.path.splitext(os.path.basename(os.path.abspath(__file__)))

# Migrations folder need to be created, and django needs to be told where it is
APP_MIGRATION_MODULE = '%s_migrations' % APP_LABEL
APP_MIGRATION_PATH = os.path.join(BASE_DIR, APP_MIGRATION_MODULE)

# Create the folder and a __init__.py if they don't exist
if not os.path.exists(APP_MIGRATION_PATH):
    os.makedirs(APP_MIGRATION_PATH)
    open(os.path.join(APP_MIGRATION_PATH, '__init__.py'), 'w').close()

# Hack to trick Django into thinking this file is actually a package
sys.modules[APP_LABEL] = sys.modules[__name__]
sys.modules[APP_LABEL].__path__ = [os.path.abspath(__file__)]

settings.configure(
    DEBUG=True,
    ROOT_URLCONF='%s.urls' % APP_LABEL,
    MIDDLEWARE=(),
    INSTALLED_APPS=[APP_LABEL, 'django.contrib.postgres'],
    MIGRATION_MODULES={APP_LABEL: APP_MIGRATION_MODULE},
    SITE_ID=1,
    DATABASES={
        'default': {
            'ENGINE': 'django.db.backends.postgresql',
            'NAME': 'postgres',
            'USER': 'postgres',
            'PASSWORD': '',
            'HOST': '127.0.0.1',
            'PORT': '5432',
        }
    },
    LOGGING={
        'version': 1,
        'disable_existing_loggers': False,
        'formatters': {
            'simple': {
                'format': "%(levelname)s %(message)s",
            },
        },
        'handlers': {
            'console': {
                'level': 'DEBUG',
                'class': 'logging.StreamHandler',
                'formatter': 'simple',
            }
        },
        'loggers': {
            'django.db.backends': {'handlers': ['console'], 'level': 'DEBUG', 'propagate': False},
            'django.db.backends.schema': {'level': 'ERROR'},  # Causes sql logs to duplicate -- really annoying
        }
    },
    STATIC_URL='/static/'
)

django.setup()

# Setup the AppConfig so we don't have to add the app_label to all our models
def get_containing_app_config(module):
    if module == '__main__':
        return apps.get_app_config(APP_LABEL)
    return apps._get_containing_app_config(module)


apps._get_containing_app_config = apps.get_containing_app_config
apps.get_containing_app_config = get_containing_app_config


# Your code below this line
# ##############################################################################

from django.test import TestCase  # noqa: E402 isort:skip
from django.db import models  # noqa: E402 isort:skip
from django import forms # noqa: E402 isort:skip
from django.contrib.postgres.fields import HStoreField
from django.forms import formset_factory
from decimal import Decimal


class Product(models.Model):
    name = models.CharField(max_length=255, blank=False, null=False)


class ProductVariant(models.Model):
    name = models.CharField(max_length=255, blank=False, null=False)
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    attributes = HStoreField()
    price = models.DecimalField(blank=False, null=False, default=0, max_digits=6, decimal_places=2)


class ProductVariantForm(forms.ModelForm):
    class Meta:
        fields = ('name', 'product', 'attributes', 'price')
        model = ProductVariant


ProductVariantFormSet = formset_factory(ProductVariantForm)


urlpatterns = []


class SimpleTestCase(TestCase):

    def setUp(self):
        self.product1 = Product.objects.create(name='Circle')
        self.product2 = Product.objects.create(name='Square')
        self.product3 = Product.objects.create(name='Triangle')

    def test_form(self):
        form = ProductVariantForm(data={'name': 'thing', 'product': self.product1.id, 'attributes': {'a': 1, 'b': 2}, 'price': '100.00'})
        self.assertEqual(True, form.is_valid())
        instance = form.save()

        self.assertEqual('thing', instance.name)
        self.assertEqual('Circle', instance.product.name)
        self.assertEqual({'a': '1', 'b': '2'}, instance.attributes)
        self.assertEqual(Decimal('100.00'), instance.price)

    def test_formset(self):
        data = {
            'form-INITIAL_FORMS': '1',
            'form-TOTAL_FORMS': '3',
            'form-MAX_NUM_FORMS': '1000',
            'form-0-name': 'thing',
            'form-0-product': self.product1.id,
            'form-0-attributes': {'a': 1, 'b': 1},
            'form-0-price': '100.00',
            'form-1-name': 'thing2',
            'form-1-product': self.product2.id,
            'form-1-attributes': {'a': 2, 'b': 2},
            'form-1-price': '200.00',
            'form-2-name': 'thing3',
            'form-2-product': self.product3.id,
            'form-2-attributes': {'a': 3, 'b': 3},
            'form-2-price': '300.00'
        }
        formset = ProductVariantFormSet(data=data)
        self.assertEqual(True, formset.is_valid())
        instances = []
        for form in formset:
            if form.is_valid():
                instances.append(form.save())

        self.assertEqual('thing', instances[0].name)
        self.assertEqual('Circle', instances[0].product.name)
        self.assertEqual({'a': '1', 'b': '1'}, instances[0].attributes)
        self.assertEqual(Decimal('100.00'), instances[0].price)

        self.assertEqual('thing2', instances[1].name)
        self.assertEqual('Square', instances[1].product.name)
        self.assertEqual({'a': '2', 'b': '2'}, instances[1].attributes)
        self.assertEqual(Decimal('200.00'), instances[1].price)

        self.assertEqual('thing3', instances[2].name)
        self.assertEqual('Triangle', instances[2].product.name)
        self.assertEqual({'a': '3', 'b': '3'}, instances[2].attributes)
        self.assertEqual(Decimal('300.00'), instances[2].price)

# Your code above this line
# ##############################################################################


# Used so you can do 'from <name of file>.models import *'
models_module = ModuleType('%s.models' % (APP_LABEL))
tests_module = ModuleType('%s.tests' % (APP_LABEL))
urls_module = ModuleType('%s.urls' % (APP_LABEL))
urls_module.urlpatterns = urlpatterns
for variable_name, value in list(locals().items()):
    # We are only interested in models
    if inspect.isclass(value) and issubclass(value, models.Model):
        setattr(models_module, variable_name, value)
    # We are only interested in tests
    if inspect.isclass(value) and issubclass(value, TestCase):
        setattr(tests_module, variable_name, value)

# Setup the fake modules
sys.modules[models_module.__name__] = models_module
sys.modules[tests_module.__name__] = tests_module
sys.modules[urls_module.__name__] = urls_module
sys.modules[APP_LABEL].models = models_module
sys.modules[APP_LABEL].tests = tests_module
sys.modules[APP_LABEL].urls = urls_module


if __name__ == "__main__":
    # Hack to fix tests
    argv = [arg for arg in sys.argv if not arg.startswith('-')]
    if len(argv) == 2 and argv[1] == 'test':
        sys.argv.append(APP_LABEL)

    from django.core.management import execute_from_command_line
    execute_from_command_line(sys.argv)
else:
    from django.core.wsgi import get_wsgi_application
    get_wsgi_application()

docker run -it --rm python:3.7 bash -xc '
apt update && 
apt install postgresql -y && 
su - postgres -c "/usr/lib/postgresql/11/bin/initdb -D /tmp/db"
su - postgres -c "/usr/lib/postgresql/11/bin/postgres -D /tmp/db" &

curl -L https://gist.githubusercontent.com/kingbuzzman/937a9d207bd937d1b2bb22249ae6bdb2/raw/formset_example.py > formset_example.py
pip install django==2.2 psycopg2==2.8.6
psql -U postgres -d template1 -c "CREATE EXTENSION IF NOT EXISTS hstore;"
python formset_example.py makemigrations
python formset_example.py test
'

Answers stackoverflow question: https://stackoverflow.com/questions/64167862/how-to-create-multiple-objects-with-different-values-at-a-time-in-django