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Saving Mr. Banks

Let’s create a service to illustrate making a service with OO models. We can use an example of a banking application.

Create synthetic transaction components

This would include object components like Transaction, Account, and a Bank that uses these components.

# Record and hold transactions (deposits, withdrawals and transfers).

from datetime import datetime

class Transaction:
    def __init__(self, transaction_id, amount, timestamp, transaction_type, account_id):
        self.transaction_id = transaction_id
        self.amount = amount
        self.timestamp = datetime.strptime(timestamp, '%Y-%m-%d %H:%M:%S')
        self.transaction_type = transaction_type
        self.account_id = account_id

    def __str__(self):
        return (f"Transaction(id={self.transaction_id}, amount={self.amount}, "
                f"timestamp={self.timestamp}, type={self.transaction_type}, "
                f"account_id={self.account_id})")

    def __repr__(self):
        return (f"Transaction(transaction_id={self.transaction_id}, amount={self.amount}, "
                f"timestamp={self.timestamp}, type={self.transaction_type}, account_id={self.account_id})")


class Account:
    def __init__(self, account_id):
        self.account_id = account_id
        self.balance = 0.0
        self.transactions =…