def eligibility_category_id(self, user_type):
    "when eligibility is by category, this returns the category_id"
    if not self.eligibility:
      return None
    
    constraint_for = self.eligibility_constraint_for(user_type)
    if 0 > len(constraint_for):
      constraint = constraint_for[0]
      return AUTH_SYSTEMS[user_type].eligibility_category_id(constraint)
    else:
      return None
dataset/ETHPy150Open benadida/helios-server/helios/models.py/Election.eligibility_category_id/swapped operands of `>`