CODEWITHSUNDEEP
pythondjangodjango-modelsdjango-rest-frameworkdjango-views
Hasnain Sikander
Hasnain Sikander

Reputation: 501

how to solve two model circular dependency in django

I have a file in django project models.py:

from django.db import models


class Product(models.Model):
    id = models.IntegerField(unique=True,primary_key=True)
    title = models.CharField(max_length=200)
    description = models.TextField(max_length= 100000)
    price = models.FloatField()
    count = models.IntegerField(default=1)
    file_content = models.ManyToManyField(ProductImage, related_name='file_content', blank=True, null=True)

    offer= models.BooleanField(default=False)

    def __str__(self):
        return self.title

class ProductImage(models.Model):
    property_id = models.ForeignKey(Product,on_delete=models.CASCADE)
    image = models.FileField(upload_to='pics')
    

    def __str__(self):
        return '%s-image' % (self.property_id.title)

It says that ProductImage is not defined, which is clear because it is defined below. If I tries to move it up above like this:


class ProductImage(models.Model):
    property_id = models.ForeignKey(Product,on_delete=models.CASCADE)
    image = models.FileField(upload_to='pics')
    

    def __str__(self):
        return '%s-image' % (self.property_id.title)

 
class Product(models.Model):
    id = models.IntegerField(unique=True,primary_key=True)
    title = models.CharField(max_length=200)
    description = models.TextField(max_length= 100000)
    price = models.FloatField()
    count = models.IntegerField(default=1)
    file_content = models.ManyToManyField(ProductImage, related_name='file_content', blank=True, null=True)

    offer= models.BooleanField(default=False)

    def __str__(self):
        return self.title

Now it says Product is not defined . Can any body tell me the remedy?

What I have done so far? I tried to make a separate file called img.py and class ProductImage wrote there.Then I tried to import it here. Now it says:

Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "c:\users\hussnain\appdata\local\programs\python\python39\lib\threading.py", line 954, in _bootstrap_inner   
    self.run()
  File "c:\users\hussnain\appdata\local\programs\python\python39\lib\threading.py", line 892, in run
    self._target(*self._args, **self._kwargs)
  File "E:\UsamaComputer\env\lib\site-packages\django\utils\autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "E:\UsamaComputer\env\lib\site-packages\django\core\management\commands\runserver.py", line 110, in inner_run
    autoreload.raise_last_exception()
  File "E:\UsamaComputer\env\lib\site-packages\django\utils\autoreload.py", line 87, in raise_last_exception
    raise _exception[1]
  File "E:\UsamaComputer\env\lib\site-packages\django\core\management\__init__.py", line 375, in execute
    autoreload.check_errors(django.setup)()
  File "E:\UsamaComputer\env\lib\site-packages\django\utils\autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "E:\UsamaComputer\env\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "E:\UsamaComputer\env\lib\site-packages\django\apps\registry.py", line 114, in populate
    app_config.import_models()
  File "E:\UsamaComputer\env\lib\site-packages\django\apps\config.py", line 301, in import_models
    self.models_module = import_module(models_module_name)
  File "c:\users\hussnain\appdata\local\programs\python\python39\lib\importlib\__init__.py", line 127, in import_module 
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 790, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "E:\UsamaComputer\backend\frontend\models.py", line 2, in <module>
    from .img import ProductImage
  File "E:\UsamaComputer\backend\frontend\img.py", line 2, in <module>
    from .models import Product
ImportError: cannot import name 'Product' from partially initialized module 'frontend.models' (most likely due to a circular import) (E:\UsamaComputer\backend\frontend\models.py)

means I cannot fool him by making a circular import. can You people help me? One thank for reading and next is for solving it.

Upvotes: 2

Views: 1122

Answers (1)

Nikita Zhuikov
Nikita Zhuikov

Reputation: 1062

Try to do like that

class Product(models.Model):
    id = models.IntegerField(unique=True,primary_key=True)
    title = models.CharField(max_length=200)
    description = models.TextField(max_length= 100000)
    price = models.FloatField()
    count = models.IntegerField(default=1)
    file_content = models.ManyToManyField("ProductImage", related_name='file_content', blank=True, null=True)

    offer= models.BooleanField(default=False)

    def __str__(self):
        return self.title

class ProductImage(models.Model):
    property_id = models.ForeignKey("Product",on_delete=models.CASCADE)
    image = models.FileField(upload_to='pics')

Upvotes: 4

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