Python实现购物程序思路及代码

# 简单的购物小程序product_list = [  ['surface pro 4', 7800],  ['dell xps 15', 12000],  ['macbook', 12000],  ['小米6', 2499],  ['iphone7', 4600],  ['坚果Pro', 1499]]shopping_list = []# 判断输入的薪水格式是否正确while True:  salary = input('/n请输入您的薪水：')  if not salary.isdigit():          # 薪水不是数字，结束循环    print('/n输入格式有误！请重新输入...')    continue  breakbalance = salary = int(salary)print('/n-----------欢迎购买------------/n')# 生成带序号的商品列表for index, item in enumerate(product_list):  print(index, item)# 判断输入的序号是否符合要求while True:  while True:    i = input('/n输入您要购买的商品序号，或输入 q 取消购买：')    if i == 'q':                 # 输入 q 退出购买界面      while True:        a = input('/n是否继续购买？(Y/N)：')        if a != 'n' and a != 'N' and a != 'y' and a != 'Y':          print('/n输入格式有误，请重试...')          continue        elif a == 'y' or a == 'Y':         # 继续购买          break        else:                    # 购买完毕          if balance == salary:       # 没有买任何东西            print('/n交易结束，购买失败...')            exit()          else:               # 结算              print('/n您已成功购买以下商品：/n')            for item in shopping_list:              print(item)            print('/n共消费金额 %d 元，余额 %d 元' % (salary - balance, balance))            exit()      continue    if not i.isdigit():             # 序号不是数字，结束循环      print('/n输入格式有误！请重新输入...')      continue    i = int(i)    if i < 0 or i >= len(product_list):  # 序号范围不正确，结束循环      print('/n此商品不存在，请重新输入...')      continue    break  product = product_list[i]  price = int(product[1])  # 判断余额是否充足，够就直接扣款，不够提醒  if price <= balance:    balance -= price    shopping_list.append(product_list[i])    print('/n您已成功购买 %s ，当前余额为 %d 元' %(product, balance))  else:    print('/n购买失败，您的余额不足...')  while True:    a = input('/n是否继续购买？(Y/N)：')    if a != 'n' and a != 'N' and a != 'y' and a != 'Y':      print('/n输入格式有误，请重试...')      continue    break  if a == 'Y' or a == 'y':    continue  else:    breakif balance == salary:  print('/n交易结束，购买失败...')  exit()else:  print('/n您已成功购买以下商品：/n')  for item in shopping_list:    print(item)  print('/n共消费金额 %d 元，余额 %d 元' %(salary-balance, balance))  exit()