python - Django 上的 MakeMigration 错误 - ImportError:无法导入名称“UserProfile”
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。为此,
我注册了两个应用程序: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)
解决方案
该问题是由循环导入引起的。请注意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)
并且在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)
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