Python银行系统模块：创建账户、存款、取款和计算利息

以下是 bank 模块的代码实现：

class Account:
    def __init__(self, account_number, owner_name, balance):
        self.account_number = account_number
        self.owner_name = owner_name
        self.balance = balance

def calculate_interest(balance, rate):
    return balance * rate

class Bank:
    def __init__(self, name):
        self.name = name
        self.accounts = []

    def create_account(self, account_number, owner_name, initial_balance):
        account = Account(account_number, owner_name, initial_balance)
        self.accounts.append(account)

    def get_account(self, account_number):
        for account in self.accounts:
            if account.account_number == account_number:
                return account
        return None

# 主程序
bank = Bank('My Bank')

while True:
    print('请选择操作：')
    print('1. 创建账户')
    print('2. 存款')
    print('3. 取款')
    print('4. 计算利息')
    print('5. 退出')

    choice = input('请输入选项数字：')

    if choice == '1':
        account_number = input('请输入账号：')
        owner_name = input('请输入持有人姓名：')
        initial_balance = float(input('请输入初始余额：'))
        bank.create_account(account_number, owner_name, initial_balance)
        print('账户创建成功！')

    elif choice == '2':
        account_number = input('请输入账号：')
        account = bank.get_account(account_number)
        if account:
            deposit_amount = float(input('请输入存款金额：'))
            account.balance += deposit_amount
            print('存款成功，当前余额为：', account.balance)
        else:
            print('账户不存在！')

    elif choice == '3':
        account_number = input('请输入账号：')
        account = bank.get_account(account_number)
        if account:
            withdrawal_amount = float(input('请输入取款金额：'))
            if withdrawal_amount <= account.balance:
                account.balance -= withdrawal_amount
                print('取款成功，当前余额为：', account.balance)
            else:
                print('余额不足！')
        else:
            print('账户不存在！')

    elif choice == '4':
        account_number = input('请输入账号：')
        account = bank.get_account(account_number)
        if account:
            interest_rate = float(input('请输入利率：'))
            interest = calculate_interest(account.balance, interest_rate)
            print('计算得到的利息为：', interest)
        else:
            print('账户不存在！')

    elif choice == '5':
        print('感谢使用！')
        break

    else:
        print('无效的选项！')

你可以将上述代码保存为一个名为 bank.py 的文件，并在主程序中导入该模块来执行相应的操作。