code: def get_by_slug(slug):
          '''
          return the category record .
          '''
          rec = TabTag.select().where(TabTag.slug == slug)
          if rec.count() > 0:
              return rec.get()
          return Nonf get_by_slug(slug):
          '''
          return the category record .
          '''
          rec = TabTag.select().where(TabTag.slug == slug)
          if rec.count() > 0:
              return rec.get()
          return None
docs: return the category record .