方案一：

product_list=[('iPhone',5899),('switch',2099),('laptop',12999),('book',30),('coffee',28)
]
shopping_list=[]
while True:salary = input('salary:')if salary.isdigit():salary=int(salary)while True:print('----product_list----')for index,item in enumerate(product_list):print(index,item)print('请选择商品加入购物车')choice=input('>>>')if choice.isdigit() and -1 < int(choice) < len(product_list):if salary >= product_list[int(choice)][1]:shopping_list.append(product_list[int(choice)])print('商品[%s]已加入购物车'% product_list[int(choice)][0])salary=salary-product_list[int(choice)][1]print('您的余额：\033[31;1m%s\033[0m'% salary)else:print('\033[31;1m您的余额不足\033[0m')elif choice == 'q':print('----shopping list----')for i in shopping_list:print(i)print('您的余额：\033[31;1m%s\033[0m' % salary)exit()else:print('\033[31;1m商品[%s]不存在\033[0m'% choice)else:print('\033[31;1m请输入正确的salary!\033[0m')

方案二：

product_list=[('iPhone',5899),('switch',2099),('laptop',12999),('book',30),('coffee',28)
]
shopping_list = []
salary = input("Input your salary:")
if salary.isdigit():salary = int(salary)while True:for index,item in enumerate(product_list):#print(product_list.index(item),item)print(index,item)user_choice = input("选择要买什么>>>:")if user_choice.isdigit():user_choice = int(user_choice)if user_choice < len(product_list) and user_choice >=0:p_item = product_list[user_choice]if p_item[1] <= salary: shopping_list.append(p_item)salary -= p_item[1]print("Added %s into shopping cart,your current balance is \033[31;1m%s\033[0m" %(p_item,salary) )else:print("\033[41;1m你的余额只剩[%s]啦，还买个毛线\033[0m" % salary)else:print("product code [%s] is not exist!"% user_choice)elif user_choice == 'q':print("--------shopping list------")for p in shopping_list:print(p)print("Your current balance:",salary)exit()else:print("invalid option")