未定义“UserManager”PylancereportUndefinedVariable

抱歉，我忘记在代码中包含 `UserManager` 类的定义。请添加以下代码来定义 `UserManager` 类：

class UserManager(BaseUserManager):
    def create_user(self, email, username, password=None):
        if not email:
            raise ValueError('The Email field must be set')
        if not username:
            raise ValueError('The Username field must be set')

        user = self.model(
            email=self.normalize_email(email),
            username=username,
        )

        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_superuser(self, email, username, password=None):
        user = self.create_user(
            email=self.normalize_email(email),
            username=username,
            password=password,
        )
        user.is_staff = True
        user.is_superuser = True
        user.save(using=self._db)
        return user

然后在 `User` 类中添加以下行：

objects = UserManager()

这样，你的代码就可以正常运行了。