import datetime import RegisterDatapoint import pickle with open('registers.pkl', 'rb') as f: datapoints = pickle.load(f) RegisterDatapoint.checkRegisterList(datapoints, reset=True) newDatapoints = [] for dp in datapoints: ndp = type(dp)() for k,v in dp.__dict__.items(): ndp.__dict__[k] = v newDatapoints.append(ndp) RegisterDatapoint.checkRegisterList(newDatapoints, reset=True) with open('registers.pkl', 'wb') as f: pickle.dump(newDatapoints, f)