Storing likes and follows informations in different models gives me error: most likely due to a circ-CodePudding

I have two models: Product and User

class Product(models.Model):
    #here are information fields about Product

    likes = models.ManyToManyField(
        User, related_name="product_likes", blank=True)

    object = models.Manager()
    productobjects = ProductObjects()

    def __str__(self):
        return self.name

class User(AbstractBaseUser, PermissionsMixin):
    #here are information fields about User

    followed = models.ManyToManyField(
        Product, related_name="followed_products", blank=True)

    objects = CustomAccountManager()
    object = models.Manager()

    def __str__(self):
        return self.email

Inside Product I need to have a likes filed ManyToMany which store which users liked the product. Inside User I need to have followed field ManyToMany which store which products the user follow.

I have an error: cannot import name 'Product' from partially initialized module 'product.models' (most likely due to a circular import). How can I fix it? Or maybe can I do this differently?

I think the problem is that inside product.models I import: from users.models import User and inside users.models I import: from product.models import Product.

(I am using the likes filed just to GET number of likes, but from followed I need to GET all the products that specified user follow and informations about them)

CodePudding user response：

Your Product model needs to import the User model and vice versa. As a result the imports got stuck in an infinite loop.

You can however use a string literal to specify to what model your ManyToManyField is pointing. For example:

# no import of the models module where you define User

class Product(models.Model):
    #here are information fields about Product

    likes = models.ManyToManyField(
        'app_name.User', related_name="product_likes", blank=True
    )
    # ⋮

Here app_name is the name of the app where you defined the (custom) user model.

Since it is (likely) the user model, you here can use the AUTH_USER_MODEL setting [Django-doc]:

# no import of the models module where you define User
from django.conf import settings

class Product(models.Model):
    #here are information fields about Product

    likes = models.ManyToManyField(
        settings.AUTH_USER_MODEL, related_name="product_likes", blank=True
    )
    # ⋮