1. class bank_account: #创建一个class，叫bank_account
2. def __init__(self, name, account_number, balance): #初始化name，account_number，和balance
3. #self代表当前的实例
4. self.name = name
5. self.account_number = account_number
6. self.balance = balance
7. def make_deposit(self, deposit): #一个银行账户存钱的个方法，有一个参数，deposit，代表存钱数量
8. self.balance = self.balance + deposit #余额等于余额加上存钱的数量
9. print('Add $',deposit,'to the balance')
10.print('The balance now is', self.balance)
11.def make_withdrawal(self, withdrawal): #一个银行账户取钱的一个方法，有一个参数，withdrawal，代表取钱的数量
12. self.balance = self.balance - withdrawal #余额等于余额减去取钱的数量
13. if self.balance < 0: #如果钱不够了，就...
14. print('Not enough money')
15. self.balance = self.balance + withdrawal #把取过的钱再加到余额里，并且告诉银行账户的主人钱不够
16. else:
17. print('Subtract $', withdrawal, 'from the balance')
18. print('The balance now is', self.balance)
19. def display_balance(self): #一个银行账户看余额的一个方法
20. print('The balance is', self.balance)
21.
22.class saving_account(bank_account): #创建一个class，叫saving_account，是bank_account的子类
23. def __init__(self, name, account_number, balance, interest): #初始化name，account_number，balance，和interest
24. bank_account.__init__(self, name, account_number, balance) #调用父类的初始化函数，name，account_number，和balance
25. self.interest = interest
26.def get_balance(self, year): #一个存款账户看几年之后余额的一个方法
27. b = self.balance * ( 1 + self.interest )**year #复利公式，**是次方
28. print('The balance in', year, 'years, will be $', b)
29.
30.candy_account = saving_account('candy', '1112234', 10, 0.1) #创建一个saving_account，叫candy_account
31.
32.withdrawal_deposit_balance = str(input('Do you want to make withdrawal, make deposit, check balance, or check future balance?')) #问账户持有人要存钱，取钱，看现在的余额，还是看未来的余额
33.inputting = True
34.while inputting:
35. if withdrawal_deposit_balance == 'check balance': #如果账户持有者想要存钱，就...
36.candy_account.display_balance() #调用看现在的余额的方法
37.inputting = False
38.elif withdrawal_deposit_balance == 'withdrawal' or withdrawal_deposit_balance == 'make withdrawal': #如果账户持有者想要取钱，就...
39.dollars = float(input('How many dollars do you want to make withdrawal?')) #问账户持有者要取多少钱
40. candy_account.make_withdrawal(dollars) #调用取钱的方法
41. inputting = False
42.elif withdrawal_deposit_balance == 'deposit' or withdrawal_deposit_balance == 'make deposit': #如果账户持有者想要看现在的余额，就...
43. dollars = float(input('How many dollars do you want to make deposit')) #问账户持有者要存多少钱
44.candy_account.make_deposit(dollars) #调用存钱的方法
45.inputting = False
46. elif withdrawal_deposit_balance == 'future balance' or withdrawal_deposit_balance == 'check future balance': #如果账户持有者想要看未来的余额，就...
47. years = float(input('Which year do you want to check on? Please give the number of years after this year')) #问账户持有者又看几年之后的余额
48. candy_account.get_balance(years) #看未来的余额调用的方法
49. inputting = False
50. else:
51. print('Please enter make withdrawal, make deposit, check balance, or check future balance') #如果哪个都不是的话，就让账户持有者从新写一遍
