App'category'不提供模型'category'

Question

Django == 3.0.6

Github： https://github.com/Kifsif/pcask

├── pcask
│   ├── category
│   │   ├── admin.py
│   │   ├── apps.py
│   │   ├── models.py
│   │   ├── tests.py
│   │   └── views.py
│   └── post
│       ├── admin.py
│       ├── apps.py
│       ├── models.py
│       ├── tests.py
│       └── views.py

/ category / models.py

class Category(CommentMixin,
               TitleMixin,
               SlugMixin,
               models.Model):
    pass

from category.models import Category

/ post / models.py

class Post(TitleMixin,
           SlugMixin,
           DescriptionMixin,
           models.Model):
    ...
    category = models.ForeignKey(Category,
                                 on_delete=models.PROTECT,
                                 related_name='blog_posts')

数据库已删除并重新创建。所有迁移均已删除。在settings.py中添加了“ post”和“ category”。

进行迁移时：

(venv) michael@michael:~/PycharmProjects/pcask/pcask$ python manage.py makemigrations
Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/core/management/base.py", line 328, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/core/management/base.py", line 369, in execute
    output = self.handle(*args, **options)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/core/management/base.py", line 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/core/management/commands/makemigrations.py", line 168, in handle
    migration_name=self.migration_name,
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/db/migrations/autodetector.py", line 43, in changes
    changes = self._detect_changes(convert_apps, graph)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/db/migrations/autodetector.py", line 129, in _detect_changes
    self.new_apps = self.to_state.apps
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/utils/functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/db/migrations/state.py", line 209, in apps
    return StateApps(self.real_apps, self.models)
  File "/home/michael/PycharmProjects/pcask/venv/lib/python3.6/site-packages/django/db/migrations/state.py", line 279, in __init__
    raise ValueError("\n".join(error.msg for error in errors))
ValueError: The field post.Post.category was declared with a lazy reference to 'category.category', but app 'category' doesn't provide model 'category'.

您能帮我了解这里发生了什么吗？

Answer 1

为了使python了解目录是包，应在其中添加__init__.py。

├── pcask
├── __init__.py
│   ├── category
├── |   ├── __init__.py
│   │   ├── admin.py
│   │   ├── apps.py
│   │   ├── models.py
│   │   ├── tests.py
│   │   └── views.py
│   └── post
├── |   ├── __init__.py
│       ├── admin.py
│       ├── apps.py
│       ├── models.py
│       ├── tests.py
│       └── views.py