Düşünce Mezarlığı

from abc import ABCMeta,abstractmethod

class Transaction(metaclass= ABCMeta):
    @abstractmethod
    def execute(self):
        pass
    
class SELECT(Transaction):
    def __init__(self,transaction):
        self.trans= transaction
        
    def execute(self):
        self.trans.SELECT()
        
class INSERT(Transaction):
    def __init__(self,transaction):
        self.trans= transaction
        
    def execute(self):
        self.trans.INSERT()
        
class UPDATE(Transaction):
    def __init__(self,transaction):
        self.trans= transaction
        
    def execute(self):
        self.trans.UPDATE()

class TransactionManager:
    def SELECT(self):
        print("Performing SELECT operation!")
    
    def INSERT(self):
        print("Performing INSERT operation!")
        
    def UPDATE(self):
        print("Performing UPDATE operation!")
        
class TransactionBroker:
    def __init__(self):
        self.__transactionQeueue = []
        
    def requestTransaction(self,transaction):
        self.__transactionQeueue.append(transaction)
        transaction.execute()
        
if __name__ == '__main__':
    traction= TransactionManager()
    tr_select= SELECT(traction)
    tr_insert= INSERT(traction)
    tr_update= UPDATE(traction)
    
    brkr= TransactionBroker()
    brkr.requestTransaction(tr_select)
    brkr.requestTransaction(tr_insert)
    brkr.requestTransaction(tr_update)
    brkr.requestTransaction(tr_select)
    brkr.requestTransaction(tr_insert)