models.py

class Student(AbstractBaseUser):
    email = models.EmailField(
        verbose_name='email address',
        max_length=255
    )

    phone = models.CharField(max_length=11)
    phone_confirmed = models.BooleanField(default=False)
    name = models.CharField(max_length=20)
    second_name = models.CharField(max_length=20)
    patronymic = models.CharField(max_length=20)
    code = models.CharField(max_length=15, unique=True, db_index=True)
    gang = models.ForeignKey(Gang, null=True)
    is_warden = models.BooleanField(default=False)
    
    # ...