小编Sun*_*mar的帖子

这是我的 models.py 代码。任何人都可以让我知道这段代码有什么问题吗？

 from django.db import models
    from unittest.util import _MAX_LENGTH

    class Album(models.Model):
            artist = models.CharField(_MAX_LENGTH=250)
            album_title = models.CharField(_MAX_LENGTH=500)
            genre = models.CharField(_MAX_LENGTH=100)
            album_logo = models.CharField(_MAX_LENGTH=1000)

    class Song(models.Model):
        album = models.ForeignKey(Album, on_delete = models.CASCADE)
        file_type = models.CharField(_MAX_LENGTH=10)
        song_title = models.CharField(_MAX_LENGTH=250)

运行命令 python manage.py migrations music 时，出现此错误

Traceback (most recent call last):
  File "/home/sunil/workspace/DjangoApp1/manage.py", line 11, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/lib/python2.7/dist-packages/django/core/management/__init__.py", line 354, in execute_from_command_line
    utility.execute()
  File "/usr/lib/python2.7/dist-packages/django/core/management/__init__.py", line 328, in execute
    django.setup()
  File "/usr/lib/python2.7/dist-packages/django/__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/usr/lib/python2.7/dist-packages/django/apps/registry.py", …