I'm trying to split the models.py
of my app into several files:
My first guess was do this:
myproject/
settings.py
manage.py
urls.py
__init__.py
app1/
views.py
__init__.py
models/
__init__.py
model1.py
model2.py
app2/
views.py
__init__.py
models/
__init__.py
model3.py
model4.py
This doesn't work, then i found this, but in this solution i still have a problem, when i run python manage.py sqlall app1
I got something like:
BEGIN;
CREATE TABLE "product_product" (
"id" serial NOT NULL PRIMARY KEY,
"store_id" integer NOT NULL
)
;
-- The following references should be added but depend on non-existent tables:
-- ALTER TABLE "product_product" ADD CONSTRAINT "store_id_refs_id_3e117eef" FOREIGN KEY ("store_id") REFERENCES "store_store" ("id") DEFERRABLE INITIALLY DEFERRED;
CREATE INDEX "product_product_store_id" ON "product_product" ("store_id");
COMMIT;
I'm not pretty sure about this, but i'm worried aboout the part The following references should be added but depend on non-existent tables:
This is my model1.py file:
from django.db import models
class Store(models.Model):
class Meta:
app_label = "store"
This is my model3.py file:
from django.db import models
from store.models import Store
class Product(models.Model):
store = models.ForeignKey(Store)
class Meta:
app_label = "product"
And apparently works but i got the comment in alter table
and if I try this, same thing happens:
class Product(models.Model):
store = models.ForeignKey('store.Store')
class Meta:
app_label = "product"
So, should I run the alter for references manually? this may bring me problems with south?
from app1.models.model1 import Store
?
For anyone on Django 1.9, it is now supported by the framework without defining the class meta data.
https://docs.djangoproject.com/en/1.9/topics/db/models/#organizing-models-in-a-package
NOTE: For Django 2, it's still the same
The manage.py startapp command creates an application structure that includes a models.py file. If you have many models, organizing them in separate files may be useful. To do so, create a models package. Remove models.py and create a myapp/models/ directory with an __init__.py file and the files to store your models. You must import the models in the __init__.py file.
So, in your case, for a structure like
app1/
views.py
__init__.py
models/
__init__.py
model1.py
model2.py
app2/
views.py
__init__.py
models/
__init__.py
model3.py
model4.py
You only need to do
#myproject/app1/models/__init__.py:
from .model1 import Model1
from .model2 import Model2
#myproject/app2/models/__init__.py:
from .model3 import Model3
from .model4 import Model4
A note against importing all the classes:
Explicitly importing each model rather than using from .models import * has the advantages of not cluttering the namespace, making code more readable, and keeping code analysis tools useful.
I'd do the following:
myproject/
...
app1/
views.py
__init__.py
models.py
submodels/
__init__.py
model1.py
model2.py
app2/
views.py
__init__.py
models.py
submodels/
__init__.py
model3.py
model4.py
Then
#myproject/app1/models.py:
from submodels/model1.py import *
from submodels/model2.py import *
#myproject/app2/models.py:
from submodels/model3.py import *
from submodels/model4.py import *
But, if you don't have a good reason, put model1 and model2 directly in app1/models.py and model3 and model4 in app2/models.py
---second part---
This is app1/submodels/model1.py file:
from django.db import models
class Store(models.Model):
class Meta:
app_label = "store"
Thus correct your model3.py file:
from django.db import models
from app1.models import Store
class Product(models.Model):
store = models.ForeignKey(Store)
class Meta:
app_label = "product"
Edited, in case this comes up again for someone: Check out django-schedule for an example of a project that does just this. https://github.com/thauber/django-schedule/tree/master/schedule/models https://github.com/thauber/django-schedule/
from product.models import Product
: ImportError: No module named models
models.py
file. I recently did this when mine grew to over 15k lines of code. Great writeup though. The process is fairly simple. The main caveat being you have to remember to define an explicit app_label, since Django extracts this from the immediate module by default.
__init__.py
and everything seems to be working okay. I did not have to correct my model files. I'm able to fetch and create objects from the shell and the django admin. I've been trying django for like a week so I'm wondering if the newest version now allows for this to happen?
I've actually come across a tutorial for exactly what you're asking about, you can view it here:
http://paltman.com/breaking-apart-models-in-django/
One key point that's probably relevant - you may want to use the db_table field on the Meta class to point the relocated classes back at their own table.
I can confirm this approach is working in Django 1.3
The relevant link for Django 3 is:
https://docs.djangoproject.com/en/3.2/topics/db/models/#organizing-models-in-a-package
Links to previous versions of documentation are broken. The example there is very succinct:
To do so, create a models package. Remove models.py and create a myapp/models/ directory with an init.py file and the files to store your models. You must import the models in the init.py file.
For example, if you had organic.py and synthetic.py in the models directory:
from .organic import Person
from .synthetic import Robot
Easiest Steps :
Create model folder in your app (Folder name should be model) Delete model.py file from app directory (Backup the file while you delete it) And after create init.py file in model folder And after init.py file in write simple one line And after create model file in your model folder and model file name should be same like as class name,if class name is 'Employee' than model file name should be like 'employee.py' And after in model file define your database table same as write like in model.py file Save it
My Code : from django_adminlte.models.employee import Employee For your : from app_name.models.model_file_name_only import Class_Name_which_define_in_model_file
__init__.py
from django_adminlte.models.employee import Employee
model/employee.py (employee is separate model file)
from django.db import models
class Employee(models.Model):
eid = models.CharField(max_length=20)
ename = models.CharField(max_length=20)
eemail = models.EmailField()
econtact = models.CharField(max_length=15)
class Meta:
db_table = "employee"
# app_label = 'django_adminlte'
def __str__(self):
return self.ename
RuntimeError ModelX doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS.
in django 2.x.
I wrote a script that might be useful.
github.com/victorqribeiro/splitDjangoModels
it split the models in individual files with proper naming and importing; it also create an init file so you can import all your models at once.
let me know if this helps
Success story sharing
models.py
and want to migrate later. In that case, you have to delete your migrations and your database :/ Or to manually solve all errors in all migration files