python-3.x - Django 上的 MakeMigration 错误 - ImportError : cannot import name 'FieldDoesNotExist' from 'django.db.models'

Question

添加新模型字段并运行 makemigrations 命令后，出现以下错误:
导入错误:无法从 'django.db.models' 导入名称 'FieldDoesNotExist' (/usr/local/lib/python3.7/site-packages/django/db/models/ init .py)
这是我的models.py 的样子:

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

这是我的迁移文件的当前状态，我有两个。
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')),
            ],
        ),
    ]

这是运行 makemigration 命令后的异常回溯:

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)

所以，我不知道究竟是什么导致了这个错误，并被困在这个阶段。任何帮助将不胜感激。

Answer 1

您的版本 django-allauth FieldDoesNotExist 的导入不正确.正确的导入是:

from django.core.exceptions import FieldDoesNotExist

进口自 django.db.models大概在旧版本的 Django 中工作。
进口 was fixed在 django-allauth在 0.41.0 版本中。如果您更新 django-allauth在您的 requirements.txt或 pipenv 它应该可以解决问题。