Django上的MakeMigration错误-ImportError：无法导入名称'UserProfile'[重复]答案

【问题标题】：MakeMigration Error on Django - ImportError: cannot import name 'UserProfile' [duplicate]Django上的MakeMigration错误-ImportError：无法导入名称'UserProfile'[重复]
【发布时间】：2021-11-18 06:25:21
【问题描述】：

我想用 Django 为一个在线视频网站创建一个后端服务器。数据库中有用户信息和视频信息。我希望用户互相关注并收集视频。用户还可以上传视频。为了这 我注册了两个应用：用户和视频。并添加到 INSTALLED_APPS。写完models.py后，运行python manage.py makemigrations报错：

  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'

这是用户->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)

这是视频->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)

【问题讨论】：

您有一个必须解决的循环导入。
还没解决。同样的错误
@WangYi 请说明你是如何更新代码的。
删除循环导入...在user.models 你有：from video.models import Video 在video.models 你有from user.models import UserProfile...
这是circular imports 故障。每个人都成功地解决了我的问题。非常感谢

标签： python django

【解决方案1】：

问题是由circular imports 引起的。请注意users/models.py的变化。

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)

在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)

【讨论】：