Do I need to import class on it's own file?-CodePudding

Ok so, I have created 2 model classes for my Django Rest application and am trying to use foreign key to join both models.

Here's my code:

from django.db import models

class Article(models.Model):
    title = models.CharField(max_length=100)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)
    date = models.DateTimeField(auto_now_add=True)



class Author(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(max_length=100)

The thing is, the Article parameter in the ForeignKey has a "Author" is not defined warning. What am I doing wrong here? Should't the classes in the same file all be "imported" already?

Do I really need to import the class in the same file it is being used?

CodePudding user response：

The classes in .py file are load with order from the begining of file. So one way is to change order of class declaration:

class Author(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(max_length=100)


class Article(models.Model):
    title = models.CharField(max_length=100)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)
    date = models.DateTimeField(auto_now_add=True)

Or django models allow us to use psedonames (for complicated relations it's not easy to order classes one after another):

class Article(models.Model):
    title = models.CharField(max_length=100)
    author = models.ForeignKey('Author', on_delete=models.CASCADE)
    date = models.DateTimeField(auto_now_add=True)


class Author(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(max_length=100)

You can remove from . import Author