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MakeMigration Error on Django - ImportError: cannot import name 'FieldDoesNotExist' from 'django.db.models'


I got the following error after adding a new model field and running the makemigrations command:

ImportError: cannot import name 'FieldDoesNotExist' from 'django.db.models' (/usr/local/lib/python3.7/site-packages/django/db/models/init.py)

this is what my models.py looks like:

import uuid
from django.contrib.auth import get_user_model
from django.db import models
from django.urls import reverse

# Create your models here.
class Book(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    title = models.CharField(max_length=200)
    author = models.CharField(max_length=200)
    price = models.DecimalField(max_digits=6, decimal_places=2)
    cover = models.ImageField(upload_to='covers/', blank=True) # New Field

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse('book_detail', args=[str(self.id)])

class Review(models.Model):
    book = models.ForeignKey(Book, on_delete=models.CASCADE, related_name='reviews')
    review = models.CharField(max_length=255)
    author = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)

    def __str__(self):
        return self.review

This is the current state of my migrations files, I have two. 0001_initial.py

# Generated by Django 3.0.8 on 2020-08-01 13:11

from django.db import migrations, models
import uuid


class Migration(migrations.Migration):

    initial = True

    dependencies = [
    ]

    operations = [
        migrations.CreateModel(
            name='Book',
            fields=[
                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
                ('title', models.CharField(max_length=200)),
                ('author', models.CharField(max_length=200)),
                ('price', models.DecimalField(decimal_places=2, max_digits=6)),
            ],
        ),
    ]

0002_review.py

# Generated by Django 3.0.8 on 2020-08-06 11:21

from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion


class Migration(migrations.Migration):

    dependencies = [
        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
        ('books', '0001_initial'),
    ]

    operations = [
        migrations.CreateModel(
            name='Review',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('review', models.CharField(max_length=255)),
                ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
                ('book', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='reviews', to='books.Book')),
            ],
        ),
    ]

This is the exception traceback after running makemigration command:

Exception in thread django-main-thread:
web_1  | Traceback (most recent call last):
web_1  |   File "/usr/local/lib/python3.7/threading.py", line 926, in _bootstrap_inner
web_1  |     self.run()
web_1  |   File "/usr/local/lib/python3.7/threading.py", line 870, in run
web_1  |     self._target(*self._args, **self._kwargs)
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/utils/autoreload.py", line 53, in wrapper
web_1  |     fn(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 110, in inner_run
web_1  |     autoreload.raise_last_exception()
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/utils/autoreload.py", line 76, in raise_last_exception
web_1  |     raise _exception[1]
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/core/management/__init__.py", line 357, in execute
web_1  |     autoreload.check_errors(django.setup)()
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/utils/autoreload.py", line 53, in wrapper
web_1  |     fn(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/__init__.py", line 24, in setup
web_1  |     apps.populate(settings.INSTALLED_APPS)
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/apps/registry.py", line 114, in populate
web_1  |     app_config.import_models()
web_1  |   File "/usr/local/lib/python3.7/site-packages/django/apps/config.py", line 211, in import_models
web_1  |     self.models_module = import_module(models_module_name)
web_1  |   File "/usr/local/lib/python3.7/importlib/__init__.py", line 127, in import_module
web_1  |     return _bootstrap._gcd_import(name[level:], package, level)
web_1  |   File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
web_1  |   File "<frozen importlib._bootstrap>", line 983, in _find_and_load
web_1  |   File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
web_1  |   File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
web_1  |   File "<frozen importlib._bootstrap_external>", line 728, in exec_module
web_1  |   File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
web_1  |   File "/usr/local/lib/python3.7/site-packages/allauth/account/models.py", line 14, in <module>
web_1  |     from .adapter import get_adapter
web_1  |   File "/usr/local/lib/python3.7/site-packages/allauth/account/adapter.py", line 31, in <module>
web_1  |     from ..utils import (
web_1  |   File "/usr/local/lib/python3.7/site-packages/allauth/utils.py", line 15, in <module>
web_1  |     from django.db.models import FieldDoesNotExist, FileField
web_1  | ImportError: cannot import name 'FieldDoesNotExist' from 'django.db.models' (/usr/local/lib/python3.7/site-packages/django/db/models/__init__.py)

So, I do not know what exactly caused this error and am stuck at this stage. Any help would be greatly appreciated.


Solution

  • Your version of django-allauth has the incorrect import for FieldDoesNotExist. The correct import is:

    from django.core.exceptions import FieldDoesNotExist
    

    The import from django.db.models presumably worked in older versions of Django.

    The import was fixed in django-allauth in version 0.41.0. If you update django-allauth in your requirements.txt or pipenv it should fix the problem.