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银行系统

本课属于 Coddy Python 学习旅程的“面向对象编程”单元。第 62 课，共 64 课。

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挑战

困难

在这个挑战中，你将构建一个银行系统，其中包含多种账户类型、交易记录和一个中央银行管理器。

请完成以下文件中的 TODO 项目，实现这个银行系统：

  • transaction.py，用于记录财务活动的 Transaction 类
  • account.py，包含通用功能的抽象基类 Account
  • savingsaccount.py，包含利息和最低余额功能的 SavingsAccount 实现
  • checkingaccount.py，支持透支功能的 CheckingAccount 实现
  • bank.py，用于管理账户和转账的 Bank 类

亲手试试

from transaction import Transaction
from account import Account
from savingsaccount import SavingsAccount
from checkingaccount import CheckingAccount
from bank import Bank

# 覆盖所有场景和边界情况的综合测试用例处理程序
test_case = input()

if test_case == "transaction_class":
    # 测试 Transaction 类
    transaction = Transaction("deposit", 100.50, None)
    print(str(transaction))
    
    transaction = Transaction("withdrawal", 75.25, None)
    print(str(transaction))

elif test_case == "account_deposit":
    # 测试存款功能
    savings = SavingsAccount("S123", "John Doe", 500)
    
    # 正数金额
    success, message = savings.deposit(200)
    print(f"Success: {success}")
    print(f"Message: {message}")
    print(f"Balance: ${savings.get_balance():.2f}")
    
    # 负数金额（应失败）
    success, message = savings.deposit(-50)
    print(f"Success: {success}")
    print(f"Message: {message}")

elif test_case == "savings_withdraw":
    # 测试储蓄账户取款
    savings = SavingsAccount("S123", "John Doe", 500, min_balance=200)
    
    # 有效的取款
    success, message = savings.withdraw(100)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 无效的取款（低于最低余额）
    success, message = savings.withdraw(300)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 负数金额
    success, message = savings.withdraw(-50)
    print(f"Success: {success}")
    print(f"Message: {message}")

elif test_case == "checking_withdraw":
    # 测试支票账户取款
    checking = CheckingAccount("C123", "Jane Smith", 300, overdraft_limit=200)
    
    # 正常取款
    success, message = checking.withdraw(100)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 透支取款
    success, message = checking.withdraw(300)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 超过透支限额
    success, message = checking.withdraw(200)
    print(f"Success: {success}")
    print(f"Message: {message}")

elif test_case == "interest_application":
    # 测试利息计算与入账
    savings = SavingsAccount("S123", "John Doe", 1000, interest_rate=0.05)
    success, message = savings.apply_interest()
    print(f"Success: {success}")
    print(f"Message: {message}")
    print(f"New Balance: ${savings.get_balance():.2f}")
    
    # 检查交易记录
    transactions = savings.get_transaction_history()
    print(f"Transaction count: {len(transactions)}")
    print(f"Last transaction: {transactions[-1]}")

elif test_case == "bank_create_account":
    # 测试银行账户创建
    bank = Bank("Test Bank")
    
    # 创建储蓄账户
    success, message = bank.create_account("savings", "S123", "John Doe", 1000, interest_rate=0.03)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 创建支票账户
    success, message = bank.create_account("checking", "C456", "Jane Smith", 500, overdraft_limit=300)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 使用重复的账号创建账户
    success, message = bank.create_account("savings", "S123", "Another Person", 200)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 使用无效类型创建账户
    success, message = bank.create_account("invalid", "I789", "Test Person", 100)
    print(f"Success: {success}")
    print(f"Message: {message}")

elif test_case == "bank_transfer":
    # 测试银行转账功能
    bank = Bank("Transfer Test Bank")
    
    # 创建两个账户
    bank.create_account("savings", "S123", "John Doe", 1000, min_balance=100)
    bank.create_account("checking", "C456", "Jane Smith", 500)
    
    # 有效转账
    success, message = bank.transfer("S123", "C456", 300)
    print(f"Success: {success}")
    print(f"Message: {message}")
    print(f"Source balance: ${bank.get_account('S123').get_balance():.2f}")
    print(f"Destination balance: ${bank.get_account('C456').get_balance():.2f}")
    
    # 无效转账（转账后余额低于最低余额要求）
    success, message = bank.transfer("S123", "C456", 700)
    print(f"Success: {success}")
    print(f"Message: {message}")
    
    # 无效账户
    success, message = bank.transfer("NONEXISTENT", "C456", 100)
    print(f"Success: {success}")
    print(f"Message: {message}")

elif test_case == "full_banking_workflow":
    # 测试完整流程
    bank = Bank("Full Workflow Bank")
    
    # 创建账户
    bank.create_account("savings", "S123", "John Doe", 1000, interest_rate=0.05, min_balance=200)
    bank.create_account("checking", "C456", "Jane Smith", 500, overdraft_limit=250)
    
    # 存款
    savings = bank.get_account("S123")
    checking = bank.get_account("C456")
    
    savings.deposit(300)
    checking.deposit(200)
    
    # 转账
    bank.transfer("S123", "C456", 400)
    
    # 为储蓄账户计息
    savings.apply_interest()
    
    # 从支票账户透支取款
    checking.withdraw(900)
    
    # 输出最终状态
    print("Final Account States:")
    print(f"Savings (S123): ${savings.get_balance():.2f}")
    print(f"Checking (C456): ${checking.get_balance():.2f}")
    
    print("\nTransaction History (Savings):")
    for transaction in savings.get_transaction_history():
        print(f"- {transaction}")
    
    print("\nTransaction History (Checking):")
    for transaction in checking.get_transaction_history():
        print(f"- {transaction}")

elif test_case == "inheritance_validation_test":
    # 全面验证继承关系
    objects = []
    if 'Transaction' in locals():
        objects.append(Transaction('test_param', 100, None))
    if 'SavingsAccount' in locals():
        objects.append(SavingsAccount('test_param', 'Test User'))  
    if 'CheckingAccount' in locals():
        objects.append(CheckingAccount('test_param', 'Test User'))
    if 'Bank' in locals():
        objects.append(Bank('test_param'))
    
    for obj in objects:
        print(f'{type(obj).__name__}:')
        print(f'  MRO: {[cls.__name__ for cls in type(obj).__mro__]}')
        print()

elif test_case == "method_overriding_test":
    # 测试方法重写的行为
    print('Testing method overriding...')
    # 创建实例并测试重写后的方法
    if 'SavingsAccount' in locals():
        obj = SavingsAccount('test', 'Test User')
        print(f'SavingsAccount methods work correctly')
    if 'CheckingAccount' in locals():
        obj = CheckingAccount('test', 'Test User')
        print(f'CheckingAccount methods work correctly')

elif test_case == "attribute_access_test":
    # 测试属性访问
    print('Testing attribute access...')
    if 'Transaction' in locals():
        obj = Transaction('test', 100, None)
        print(f'Transaction attributes accessible')
    if 'SavingsAccount' in locals():
        obj = SavingsAccount('test', 'Test User')
        print(f'SavingsAccount attributes accessible')
    if 'CheckingAccount' in locals():
        obj = CheckingAccount('test', 'Test User')
        print(f'CheckingAccount attributes accessible')
    if 'Bank' in locals():
        obj = Bank('test')
        print(f'Bank attributes accessible')

elif test_case == "boundary_conditions_test":
    # 测试边界条件和极端值
    print('Running boundary_conditions_test test...')
    print('Test completed successfully')

elif test_case == "error_handling_test":
    # 测试错误处理和异常情况
    print('Running error_handling_test test...')
    print('Test completed successfully')

elif test_case == "polymorphic_behavior_test":
    # 使用不同类型的对象测试多态行为
    print('Running polymorphic_behavior_test test...')
    print('Test completed successfully')

elif test_case == "stress_test":
    # 使用多个对象进行压力测试
    import time
    start_time = time.time()
    
    objects = []
    for i in range(50):
        try:
            objects.append(Transaction(f'test_{i}', 100, None))
        except:
            pass  # 妥善处理创建时的错误
        try:
            objects.append(SavingsAccount(f'test_{i}', f'User_{i}'))
        except:
            pass  # 妥善处理创建时的错误
        try:
            objects.append(CheckingAccount(f'test_{i}', f'User_{i}'))
        except:
            pass  # 妥善处理创建时的错误
        try:
            objects.append(Bank(f'test_{i}'))
        except:
            pass  # 妥善处理创建时的错误
    
    end_time = time.time()
    print(f'Created {len(objects)} objects')
    print(f'Time taken: {end_time - start_time:.4f} seconds')
    print('Stress test completed')

elif test_case == "comprehensive_validation":
    # 全面验证测试
    print('=== Comprehensive Validation Test ===')
    
    # 测试 1：创建基本对象
    print('1. Basic Object Creation:')
    success_count = 0
    classes = ['Transaction', 'SavingsAccount', 'CheckingAccount', 'Bank']
    
    try:
        obj = Transaction('test', 100, None)
        success_count += 1
        print(f'   Transaction: Created successfully')
    except Exception as e:
        print(f'   Transaction: Creation failed - {e}')
    try:
        obj = SavingsAccount('test', 'Test User')
        success_count += 1
        print(f'   SavingsAccount: Created successfully')
    except Exception as e:
        print(f'   SavingsAccount: Creation failed - {e}')
    try:
        obj = CheckingAccount('test', 'Test User')
        success_count += 1
        print(f'   CheckingAccount: Created successfully')
    except Exception as e:
        print(f'   CheckingAccount: Creation failed - {e}')
    try:
        obj = Bank('test')
        success_count += 1
        print(f'   Bank: Created successfully')
    except Exception as e:
        print(f'   Bank: Creation failed - {e}')
    
    print(f'   Successfully created {success_count}/{len(classes)} classes')
    
    print('=== Validation Complete ===')

面向对象编程中的所有课

1OOP 基础

OOP 简介外部文件类与对象self 参数方法属性构造方法 (__init__)回顾：简单计算器

4继承

继承基础super() 函数方法重写多重继承方法解析顺序回顾：员工层次结构

7特殊方法

魔术方法简介运算符重载容器魔术方法回顾：自定义列表

10设计模式第 1 部分

设计模式简介单例模式工厂模式观察者模式策略模式

13最终挑战

在线学习平台银行系统游戏角色开发车辆租赁服务

2装饰器

装饰器简介属性装饰器静态方法装饰器类方法装饰器

5多态

重新认识方法重写鸭子类型抽象类和抽象方法接口设计回顾：形状计算器

8高级面向对象编程概念

组合与继承Mixin静态方法与类方法类装饰器上下文管理器

11设计模式第 2 部分

命令模式适配器模式装饰器模式模板方法模式状态模式组合模式

3类属性

实例变量与类变量属性装饰器私有属性回顾：银行账户管理器

6封装

公有、受保护和私有成员访问修饰符信息隐藏高级属性装饰器回顾：学生记录系统

9高级参数

*args 参数**kwarg 参数

12项目：图书管理

项目概览图书和用户类借阅系统搜索功能管理员界面测试与集成

自己练习： Python 在线编译器