python - 银行账户类。如何让它更强大/更高效？ (面向对象)

Question

我想让这个程序在不使用全局变量的情况下运行。基本上，如果此人退出并最终变成负数，他们将受到 5 的惩罚。每笔交易出现负数也会导致 5 的惩罚。

假设只有 2 个帐户，该程序似乎运行良好:

account1 = Bankaccount(20)
account2 = Bankaccount(5)

但这就是它的局限性。我怎样才能允许无限帐户？所以我不会局限于这两个全局变量。我希望这是有道理的，假设我必须更改取款功能和 get_fees，但我是 OOP 的新手，所以我被卡住了。感谢您的帮助!

pen = 0
pen2 = 0


class BankAccount:


 def __init__(self, initial_balance):
        """Creates an account with the given balance."""
        self.money = initial_balance

    def deposit(self, amount):
        """Deposits the amount into the account."""
        self.money += amount
        return self.money

    def withdraw(self, amount):
        """
        Withdraws the amount from the account.  Each withdrawal resulting in a
        negative balance also deducts a penalty fee of 5 dollars from the balance.
        """
        global pen, pen2
        penalty = 5

        if self.money - amount < 0:
            self.money -= (amount + penalty)
            if self == account1:
                pen += 5
            elif self == account2:
                pen2 += 5
        else:
            self.money -= amount
        return self.money


    def get_balance(self):
        """Returns the current balance in the account."""
        return self.money

    def get_fees(self):
        """Returns the total fees ever deducted from the account."""
        global pen, pen2
        if self == account1:
            return pen
        elif self == account2:
            return pen2

Answer 1

让惩罚成为一个实例属性，就像money一样:

def __init__(self, initial_balance):
        """Creates an account with the given balance."""
        self.money = initial_balance
        self.penalty = 0

然后，稍后:

def withdraw(self, amount):

    if self.money - amount < 0:
        self.penalty += 5