Django error: "Models aren't loaded yet." - django

Question

I have been making changes to my models and adding new ones (many times). But now when I ran python3 manage.py makemigrations, I suddenly got this error:
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.
I deleted all migrations and the sqlite database file to start from scratch, but I get the same error again. All my models are registered in admin.py.
I'm using Django 2.0.3.
Can someone help me with this?
Here is the full traceback:
Traceback (most recent call last):
File "manage.py", line 15, in <module>
execute_from_command_line(sys.argv)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
utility.execute()
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/core/management/__init__.py", line 347, in execute
django.setup()
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/__init__.py", line 24, in setup
apps.populate(settings.INSTALLED_APPS)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/apps/registry.py", line 112, in populate
app_config.import_models()
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/apps/config.py", line 198, in import_models
self.models_module = import_module(models_module_name)
File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 994, in _gcd_import
File "<frozen importlib._bootstrap>", line 971, in _find_and_load
File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 678, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/mnt/c/git/project3/orders/models.py", line 85, in <module>
class PizzaOrder(models.Model):
File "/mnt/c/git/project3/orders/models.py", line 90, in PizzaOrder
p = Pizza.objects.get(pk=pizza_id)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/query.py", line 394, in get
clone = self.filter(*args, **kwargs)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/query.py", line 836, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/query.py", line 854, in _filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1253, in add_q
clause, _ = self._add_q(q_object, self.used_aliases)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1277, in _add_q
split_subq=split_subq,
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1153, in build_filter
lookups, parts, reffed_expression = self.solve_lookup_type(arg)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1015, in solve_lookup_type
_, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1355, in names_to_path
if field.is_relation and not field.related_model:
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/utils/functional.py", line 36, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/db/models/fields/related.py", line 94, in related_model
apps.check_models_ready()
File "/home/anna/py3_cs50W/lib/python3.6/site-packages/django/apps/registry.py", line 132, in check_models_ready
raise AppRegistryNotReady("Models aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.
Here is my full models.py:
from django.db import models
from django.core.validators import MaxValueValidator, MinValueValidator
from django.contrib.auth.models import User
from django.conf import settings
LARGE = 'L'
SMALL = 'S'
SIZE_CHOICES = ( (SMALL, 'Small'), (LARGE, 'Large'),)
class Dish(models.Model):
PIZZA = 'PIZZA'
SUB = 'SUB'
PASTASALAD = 'PASTASALAD'
PLATTER = 'PLATTER'
TYPE_CHOICES = ( (PIZZA, 'Pizza'), (SUB, 'Sub'), (PASTASALAD, 'PastaSalad'), (PLATTER, 'Platter') )
name = models.CharField(max_length=64, blank=True) # blank makes name optional
type = models.CharField(max_length=64, choices=TYPE_CHOICES, blank=True)
size = models.CharField(max_length=1, choices=SIZE_CHOICES, default=SMALL, blank=True)
price = models.DecimalField(max_digits=6, decimal_places=2, default=None)
def __str__(self):
return f"{self.name} {self.size} - Price: ${self.price}"
class Order(models.Model):
order_id = models.AutoField(primary_key=True)
customer = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.DO_NOTHING, related_name="active_customer")#can ditch rel name
time = models.DateTimeField()
total = models.DecimalField(max_digits=7, decimal_places=2)
def __str__(self):
return f"Order {self.order_id}, customer: {self.customer}. Total: ${self.total} - {self.time}"
class PastaSalad(Dish):
dish = models.OneToOneField(Dish, on_delete=models.CASCADE, related_name="dish_id_pastasalad", parent_link=True)
def __str__(self):
return f"{self.name}, price: ${self.price}"
class Topping(models.Model):
name = models.CharField(max_length=64, primary_key=True)
def __str__(self):
return f"{self.name}"
class Pizza(Dish):
dish = models.OneToOneField(Dish, on_delete=models.CASCADE, related_name="dish_id_pizza", parent_link=True)
REGULAR = 'REGULAR'
SICILIAN = 'SICILIAN'
STYLE_CHOICES = ( (REGULAR, 'Regular'), (SICILIAN, 'Sicilian'),)
style = models.CharField(max_length=64, choices=STYLE_CHOICES, default=REGULAR)
topping_count = models.IntegerField(default=0, validators=[MaxValueValidator(5), MinValueValidator(0)])
def __str__(self):
return f"{self.size} {self.style} pizza with {self.topping_count} toppings: ${self.price}"
class Sub(Dish):
dish = models.OneToOneField(Dish, on_delete=models.CASCADE, related_name="dish_id_sub", parent_link=True)
def __str__(self):
return f"{self.name}, Size: ${self.szie}, Price: ${self.price}"
class PizzaOrder(models.Model):
pizza_id = models.ForeignKey(Pizza, related_name="pizza_id", on_delete=models.DO_NOTHING)
order_id = models.ForeignKey(Order, on_delete=models.CASCADE, related_name="pizza_order_id")
p = Pizza.objects.get(pk=pizza_id)
toppings = []
for i in range (p.topping_count):
str = "topping_"+(i+1)
toppings.append(str)
for t in toppings:
t = models.ForeignKey(Topping)
def __str__(self):
return f"Pizza Order: {self.order_id}, Size & Style: {p.size} {p.style}, Toppings: {p.topping_count}"
class Platter(Dish):
dish = models.OneToOneField(Dish, on_delete=models.CASCADE, related_name="dish_id_platter", parent_link=True)
def __str__(self):
return f"{self.name} price: ${self.price}, size ${self.size}"
class PlatterOrder(models.Model):
order_id = models.ForeignKey(Order, on_delete=models.CASCADE, related_name="platter_to_order_id")
platter_id = models.ForeignKey(Platter, related_name="platter_id")
def __str__(self):
p = Platter.objects.get(pk=platter_id)
return f"Platter Order: {self.order_id}, {p.name}, size: {p.size}"
class SubOrder(models.Model):
sub_id = models.ForeignKey(Sub, related_name="sub_id")
order_id = models.ForeignKey(Order, on_delete=models.CASCADE, related_name="sub_to_order_id")
extra_count = models.IntegerField(default=0, validators=[MaxValueValidator(4), MinValueValidator(0)])
MUSHIES = 'M'
PEPPERS = 'P'
ONIONS = 'O'
XTRCHEESE = 'C'
EXTRA_CHOICES = ((MUSHIES, 'Mushrooms'), (PEPPERS, 'Peppers'), (ONIONS, 'Onions'), (XTRCHEESE, 'Extra Cheese'),)
extra_1 = models.CharField(max_length=1, choices=EXTRA_CHOICES, blank=True)
extra_2 = models.CharField(max_length=1, choices=EXTRA_CHOICES, blank=True)
extra_3 = models.CharField(max_length=1, choices=EXTRA_CHOICES, blank=True)
extra_4 = models.CharField(max_length=1, choices=EXTRA_CHOICES, blank=True)
def __str__(self):
s = Sub.objects.get(pk=sub_id) # LET'S SEE IF THIS WORKS
extras = []
for i in range(extra_count):
str = "extra_"+i
extras.append(str)
return f"Sub Order: {self.order_id}, {s.name}, size: {s.size}. {self.extra_count} Extras: {extras}"
class PastaSaladOrder(models.Model):
order_id = models.ForeignKey(Order, on_delete=models.CASCADE, related_name="pastasalad_to_order_id")
pastasalad_id = models.ForeignKey(PastaSalad, related_name="pastasalad_id")
def __str__(self):
ps = PastaSalad.objects.get(pk=pastasalad_id) # LET'S SEE IF THIS WORKS
return f"Pasta/Salad Order: {self.order_id}, {ps.name}"

Answer 1

Your issue is here in PizzaOrder:
p = Pizza.objects.get(pk=pizza_id)
toppings = []
for i in range (p.topping_count):
str = "topping_"+(i+1)
toppings.append(str)
for t in toppings:
t = models.ForeignKey(Topping)
As the traceback suggests, your model hasn't loaded but you're trying to refer to it with .objects.get(). I think you want to link the Pizzas to the PizzaOrder, if so then you need to set this as a ForeignKey (or other relationship) in the Pizza model. Removing this segment of code should work (although you do have some missing on_delete fields in your ForeignKeys).
The structure of your models seems quite complicated, I think you can do away with the food models and foodOrder models as they probably don't add anything. You could have four models, each with their own choice fields:
Order > Platter > Dish > Topping/Extra
Dish could have a choice field which refers to pizza, pasta, etc. have a price and link to toppings/extras as needed.

Answer 2

adding
import django
django.setup()
works for me
bug i had the dir structure like
settings
|
|- base.py ( common settings for all stage)
|- dev.py
|- local.py
|- production.py
so for that i have to add above setup thing in end of all three files (dev, local, prod)
so its working fine now