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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def overall_accuracy_calc(TP, POP):
 """ Calculate overall accuracy. :param TP: true positive :type TP : dict :param POP: population :type POP:int :return: overall_accuracy as float """

    try:
        overall_accuracy = sum(TP.values()) / POP
        return overall_accuracy
    except Exception:
        return "None"