old_contents: from django.db import models
  
  
  class SkillTree(models.Model):
      name = models.CharField(max_length=128, blank=False)
  
      def __unicode__(self):
          return self.name
  
  
  class SkillTreeBranch(models.Model):
      name = models.CharField(max_length=128, blank=False)
      skill_tree = models.ForeignKey(SkillTree)
  
      def __unicode__(self):
          return self.name
  
  
  class Skill(models.Model):
      name = models.CharField(max_length=128, blank=False)
      point_req = models.IntegerField(blank=True, default=1)
      other_req = models.CharField(max_length=128, blank=True, null=True)
      skill_tree_branch = models.ForeignKey(SkillTreeBranch)
  
      def __unicode__(self):
          return self.name
  
  
  class SkillLevel(models.Model):
      level = models.IntegerField(blank=True, default=1)
      text = models.CharField(max_length=255, blank=False)
      pre_req = models.ForeignKey("self")
      skill = models.ForeignKey(Skill)
  
      def __unicode__(self):
          return "{0} {1}".format(self.skill.name, self.level)
  
new_contents: from django.db import models
  
  
  class SkillTree(models.Model):
      name = models.CharField(max_length=128, blank=False)
  
      def __unicode__(self):
          return self.name
  
  
  class SkillTreeBranch(models.Model):
      name = models.CharField(max_length=128, blank=False)
      skill_tree = models.ForeignKey(SkillTree)
  
      def __unicode__(self):
          return self.name
  
  
  class Skill(models.Model):
      name = models.CharField(max_length=128, blank=False)
      point_req = models.IntegerField(blank=True, default=1)
      other_req = models.CharField(max_length=128, blank=True, null=True)
      pre_req = models.ForeignKey("self")
      skill_tree_branch = models.ForeignKey(SkillTreeBranch)
  
      def __unicode__(self):
          return self.name
  
  
  class SkillLevel(models.Model):
      level = models.IntegerField(blank=True, default=1)
      cost = models.IntegerField(blank=True, default=1)
      text = models.CharField(max_length=255, blank=False)
      skill = models.ForeignKey(Skill)
  
      def __unicode__(self):
          return "{0} {1}".format(self.skill.name, self.level)
  
subject: adjust prereqs