Python Transaction Object Sample

class Transaction:
    start_time=None
    def __init__(self,currency,stop_loss,volume):
        self.currency=currency
        self.stop_loss=stop_loss
        self.volume=volume
        self.profitability=None
    def realise(self): #Series of instructions to realise transaction for each Capital way it will be different
        self.transaction_starttime=datetime.datetime.now()
        raise NotImplementedError("Transaction class is only a template. Subclass must implement abstract method")
    def stop(self): #stop transaction in case if profitability changes to an unwanted value parameter stop_loss
        raise NotImplementedError("Transaction class is only a template. Subclass must implement abstract method")
    def prof_watchdog(self): #check if transaction is still profitable on each realising step
        if self.profitability>=self.stop_loss:
            return True
        else:
            return False
    def conclude(self): #Update Balance and transaction history to json file
        duration_time=json.loads(open("UserDedicatedJsonData/TransactionsTime.json", "r").read())

        duration_time[self.__str__()][len(duration_time[self.__str__()])+1]=datetime.timedelta(datetime.datetime.now(),self.transaction_starttime)

        with open('UserDedicatedJsonData/TransactionsTime.json', 'w+') as outfile:
            json.dump(duration_time, outfile)

        self.transaction_starttime=0
        raise NotImplementedError("Transaction class is only a template. Subclass must implement abstract method")
    def update_prof(self):
        raise NotImplementedError("Transaction class is only a template. Subclass must implement abstract method")
    def get_profitability(self):
        return self.profitability

class KrakenBitbayTransaction(Transaction):
    def __init__(self,currency,stop_loss,volume):
        Transaction.__init__(self,currency,stop_loss,volume)
        self.profitability=Count_Circuit_Profitability.count_kraken_bitbay(self.volume,self.currency)
    def __str__(self):
        return "KrakenBitbayTransaction"+str(self.currency)
    def realise(self): #TODO this method is still as pseudocode
        currency_balance=KrakenPrivateMethods.KrakenPrivateAPI.getBalance()['$currency']
        KrakenPrivateMethods.KrakenPrivateAPI.AddBuyOrder(self,
            str(self.currency)+"EUR",HTTP_GET_DATA.kraken_BTCEUR,KrakenPrivateMethods.KrakenPrivateAPI.getBalance())
    def update_prof(self):
        self.profitability=Count_Circuit_Profitability.count_kraken_bitbay(self.volume,self.currency)