相关疑难解决方法(0)

我正在为app创建一个数据迁移Notification,在这里我正在使用Managerapp 的模型引用accounts

Manager = apps.get_model("accounts", "Manager")

它抛出错误:

    self.code(from_state.render(), schema_editor)
  File "/home/notifications/migrations/0004_auto_20150720_0127.py", line 12, in set_notification_setttings
    Manager = apps.get_model("accounts", "Manager")
  File "/home/local/lib/python2.7/site-packages/django/apps/registry.py", line 202, in get_model
    return self.get_app_config(app_label).get_model(model_name.lower())
  File "/home/local/lib/python2.7/site-packages/django/apps/registry.py", line 150, in get_app_config
    raise LookupError("No installed app with label '%s'." % app_label)
LookupError: No installed app with label 'accounts'

虽然从shell我尝试了类似的东西,它的工作原理

>> from django.apps import apps
>> apps.get_app_config('accounts').get_model('Manager'.lower())
>> accounts.models.Manager

关于为什么在迁移的情况下它失败了？