text: import numpy as np
  from openrec.legacy.utils.evaluators import Evaluator
  
  
  class AUC(Evaluator):
      def __init__(self, name="AUC"):
  
          super(AUC, self).__init__(etype="rank", name=name)
  
      def compute(self, rank_above, negative_num):
  
          return np.mean((negative_num - rank_above) / negative_num)
  