[DJ08] Model does not define __str__ method

It is recommended to define an __str__ method within a Model. The __str__ method is used whenever str(model_object) is called. Django uses the str() method as the display value on the Django Admin, otherwise the Admin will only show: [object Object] as the display value.

Don't

class Post:
    title = models.CharField()

Do

class Post:
    title = models.CharField()

    def __str__(self):
        return f'{self.title}'

References

https://docs.djangoproject.com/en/3.0/ref/models/instances/#django.db.models.Model.__str__