MakeMigration Error on Django - ImportError: cannot import name 'UserProfile' [duplicate]-CodePudding

I want to create a back-end server for an online video website with Django. There are user information and video information in the database. I want users to pay attention to each other and collect videos. Users can also upload videos. For this I registered two apps: user and video. And added to INSTALLED_APPS. After I writing models.py, I run python manage.py makemigrations and reported error:

  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "D:\Code\PycharmProjects\djangoProject_dachuang\venv\lib\site-packages\django\core\management\__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "D:\Code\PycharmProjects\djangoProject_dachuang\venv\lib\site-packages\django\core\management\__init__.py", line 395, in execute
    django.setup()
  File "D:\Code\PycharmProjects\djangoProject_dachuang\venv\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "D:\Code\PycharmProjects\djangoProject_dachuang\venv\lib\site-packages\django\apps\registry.py", line 114, in populate
    app_config.import_models()
  File "D:\Code\PycharmProjects\djangoProject_dachuang\venv\lib\site-packages\django\apps\config.py", line 301, in import_models
    self.models_module = import_module(models_module_name)
  File "D:\Program Files\Python36\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "D:\Code\PycharmProjects\djangoProject_dachuang\user\models.py", line 8, in <module>
    from video.models import Video
  File "D:\Code\PycharmProjects\djangoProject_dachuang\video\models.py", line 20, in <module>
    from user.models import UserProfile
ImportError: cannot import name 'UserProfile'

this is user->models.py:

from django.db import models
from video.models import Video


class UserProfile(models.Model):
    openid = models.CharField(max_length=50, unique=True, default='')
    nickname = models.CharField(max_length=50, default='')
    avatar = models.CharField(max_length=255, default='')
    liked_videos = models.ManyToManyField('Video',on_delete=models.CASCADE)
    fans = models.ManyToManyField('self', symmetrical=False)
    liked_users = models.ManyToManyField('self', symmetrical=False)
    created_time = models.DateTimeField(auto_now_add=True)
    updated_time = models.DateTimeField(auto_now_add=True)

this is video->models.py:

from django.db import models
from user.models import UserProfile


class Video(models.Model):
   STATUS_CHOICES = (
       ('0', 'can'),
       ('1', 'can not'),
   )
   title = models.CharField(max_length=100, blank=True, null=True)
   desc = models.CharField(max_length=255, blank=True, null=True)
   classification = models.CharField(max_length=100, blank=True, null=True)
   file = models.FileField(max_length=255, upload_to='videos', blank=True, null=True)
   cover = models.CharField(max_length=255, blank=True, null=True)
   status = models.CharField(max_length=1, choices=STATUS_CHOICES, blank=True, null=True)
   created_user = models.ForeignKey('UserProfile', max_length=255, blank=True, null=True, on_delete=models.CASCADE)
   create_time = models.DateTimeField(auto_now_add=True)
   updated_time = models.DateTimeField(auto_now_add=True)

CodePudding user response：

The issue is caused by circular imports. Please note the changes in users/models.py.

from django.db import models    

class UserProfile(models.Model):
    openid = models.CharField(max_length=50, unique=True, default='')
    nickname = models.CharField(max_length=50, default='')
    avatar = models.CharField(max_length=255, default='')
    liked_videos = models.ManyToManyField('video.Video',on_delete=models.CASCADE)
    fans = models.ManyToManyField('self', symmetrical=False)
    liked_users = models.ManyToManyField('self', symmetrical=False)
    created_time = models.DateTimeField(auto_now_add=True)
    updated_time = models.DateTimeField(auto_now_add=True)

and in video/models.py

from django.db import models    

class Video(models.Model):
   STATUS_CHOICES = (
       ('0', 'can'),
       ('1', 'can not'),
   )
   title = models.CharField(max_length=100, blank=True, null=True)
   desc = models.CharField(max_length=255, blank=True, null=True)
   classification = models.CharField(max_length=100, blank=True, null=True)
   file = models.FileField(max_length=255, upload_to='videos', blank=True, null=True)
   cover = models.CharField(max_length=255, blank=True, null=True)
   status = models.CharField(max_length=1, choices=STATUS_CHOICES, blank=True, null=True)
   created_user = models.ForeignKey('users.UserProfile', max_length=255, blank=True, null=True, on_delete=models.CASCADE)
   create_time = models.DateTimeField(auto_now_add=True)
   updated_time = models.DateTimeField(auto_now_add=True)