Mocking Django App

I'm sure this is completely wrong. I needed a Django model for testing, but I don't have a Django app or even a Django project. I'm developing a Django model reader for Carousel, and so I needed a model to test it out with. Sure I could have created a quick django project, but that seemed silly, and my first instinct was to import django.db.models, make a model and use it, but this raised:

ImproperlyConfigured: Requested setting DEFAULT_INDEX_TABLESPACE, but settings are not
                      configured. You must either define the environment variable
                      DJANGO_SETTINGS_MODULE or call settings.configure() before accessing
                      settings.

Most normal people would turn back now, but instead I imported django.conf.settings and called settings.configure() just like it said to do. Now I got this error:

AppRegistryNotReady: Apps aren't loaded yet.

So now I felt like I was getting somewhere. But where? Googling told me to import django and run setup which I did and that raised:

RuntimeError: Model class __main__.MyModel doesn't declare an explicit app_label and isn't
              in an application in INSTALLED_APPS.

Wow! Normally RuntimeError is a scary warning, like you dumped your core, but this just said I needed to add the app to settings.INSTALLED_APPS, which makes perfect sense, and it also complained that my model wasn't actually part of an app and even explained how to explicitly declare it. Some more Googling and I discovered that app_label is a model option that can be set in class Meta. So I did as told, and it worked!

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from django.db import models from django.conf import settings import django   MYAPP = 'myapp.MyApp' settings.configure() django.setup() settings.INSTALLED_APPS.append(MYAPP)     class MyModel(models.Model):     air_temp = models.FloatField()     latitude = models.FloatField()     longitude = models.FloatField()     timezone = models.FloatField()     pvmodule = models.CharField(max_length=20)       class Meta:         app_label = MYAPP     mymodel = MyModel(air_temp=25.0, latitude=38.0, longitude=-122.0,                   timezone=-8.0, pvmodule='SPR E20-327')   mymodel.__dict__ #{'_state': <django.db.models.base.ModelState at 0x496b2b0>, # 'air_temp': 25.0, # 'id': None, # 'latitude': 38.0, # 'longitude': -122.0, # 'pvmodule': 'SPR E20-327', # 'timezone': -8.0}

Caveats

So I should stop here and point out that that evidently the order of these commands matters, because if I add the fake app to INSTALLED_APPS before calling django.setup() then I get this:

ImportError: No module named myapp

And unfortunately, I just figured this out now, in this post. But this isn't what I originally did. Yes, I'm completely crazy. First I added a fake module called 'myapp' to sys.modules setting it to a mock object, but that didn't work. I got back TypeError: 'Mock' object is not iterable because, as I found out later, there has to be an AppConfig subclass in the app module. But since I didn't know that yet, I did the only logical thing and put the module in a list. What? Yes, did I mention I'm an idiot? This nonsense yielded the following stern warning:

ImproperlyConfigured: The app module [] has no filesystem location, you
                      must configure this app with an AppConfig subclass with a 'path' class
                      attribute.

But this is where I found out about AppConfig in the Django docs which is covered quite nicely. Following the nice directions, I did as told and subclassed AppConfig, added path and also name which I learned from the docs, monkeypatched my mock module with it, and used the dotted name of the app myapp.MyApp now. I felt like I was getting closer, since I only got: AttributeError: __name__ which seemed like a problem with my pretend module. Another monkeypatch and we have my final ludicrously ridiculous hack.

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from django.db import models from django.conf import settings import django from django.apps import AppConfig import sys import mock   class MyApp(AppConfig):     """     Apps subclass ``AppConfig`` and define ``name`` and ``path``     """     path = '.'  # path to app     name = 'myapp'  # name of app     # make a mock module with ``__name__`` and ``MyApp`` member myapp_module = mock.Mock(__name__='myapp', MyApp=MyApp) MYAPP = 'myapp.MyApp'  # full path to app sys.modules['myapp'] = myapp_module  # register module settings.configure() settings.INSTALLED_APPS.append(MYAPP) django.setup()     class MyModel(models.Model):     air_temp = models.FloatField()     latitude = models.FloatField()     longitude = models.FloatField()     timezone = models.FloatField()     pvmodule = models.CharField(max_length=20)       class Meta:         app_label = MYAPP     mymodel = MyModel(air_temp=25.0, latitude=38.0, longitude=-122.0,                   timezone=-8.0, pvmodule='SPR E20-327')   mymodel.__dict__ #{'_state': <django.db.models.base.ModelState at 0x496b2b0>, # 'air_temp': 25.0, # 'id': None, # 'latitude': 38.0, # 'longitude': -122.0, # 'pvmodule': 'SPR E20-327', # 'timezone': -8.0}

Yay?