code: def enr_at_fpr(fg_vals, bg_vals, fpr=0.01):
      
      pos = np.array(fg_vals)
      neg = np.array(bg_vals)
      s = scoreatpercentile(neg, 100 - fpr * 100)
      neg_matches = float(len(neg[neg >= s]))
      if neg_matches == 0:
          return float("inf")
      return len(pos[pos >= s]) / neg_matches * len(neg) / float(len(pos))
docs: Computes the enrichment at a specific FPR (default 1%).
  
      Parameters
      ----------
      fg_vals : array_like
          The list of values for the positive set.
  
      bg_vals : array_like
          The list of values for the negative set.
      
      fpr : float, optional
          The FPR (between 0.0 and 1.0).
      
      Returns
      -------
      enrichment : float
          The enrichment at the specified FPR.