code: def overall_accuracy_calc(TP, POP):
      
      try:
          overall_accuracy = sum(TP.values()) / POP
          return overall_accuracy
      except Exception:
          return "None"
docs: Calculate overall accuracy.
  
      :param TP: true positive
      :type TP : dict
      :param POP: population
      :type POP:int
      :return: overall_accuracy as float