old_contents: from django.contrib.auth.models import AbstractUser
  from django.core.urlresolvers import reverse
  from django.db import models
  
  class User(AbstractUser):
      obfuscate = models.BooleanField(default=False)
      interest_tags = models.TextField(blank=True)
      specialist_tags = models.TextField(blank=True)
      old_id = models.CharField(max_length=36, blank=True)
      org_id = models.CharField(max_length=36, blank=True, null=True)
      title = models.CharField(max_length=255, blank=True)
      rank = models.CharField(max_length=10)
  
new_contents: from django.contrib.auth.models import AbstractUser
  from django.core.urlresolvers import reverse
  from django.db import models
  
  class User(AbstractUser):
      obfuscate = models.BooleanField(default=False)
      interest_tags = models.TextField(blank=True)
      specialist_tags = models.TextField(blank=True)
      old_id = models.CharField(max_length=36, blank=True)
      org_id = models.CharField(max_length=36, blank=True, null=True)
      title = models.CharField(max_length=255, blank=True)
      rank = models.CharField(max_length=10, default="0")
  
subject: set default rank in user model