lst0 = ['购买商品','金额'] lst1 = ['1.','iphone6s','5800'] lst2 = ['2.','mac book','9000'] lst3 = ['3.','coffee','32'] lst4 = ['4.','python book','80'] lst5 = ['5.','bicycle','1500'] c = 1 while 1>0:       salary = input("Salary = ")       if salary.isdigit():           salary = int(salary)           break print(lst1[0],lst1[1],lst1[2]) print(lst2[0],lst2[1],lst2[2]) print(lst3[0],lst3[1],lst3[2]) print(lst4[0],lst4[1],lst4[2]) print(lst5[0],lst5[1],lst5[2]) while 1 > 0:     a = input('>>>:')     if a == 'quit':         d = 0         for i in range(c):             print(lst0[d], lst0[d + 1], end='\n')             d += 2         print('您的余额为：',salary)         print('欢迎下次光临')         break     elif a.isdigit():         a = int(a)         if 0 < a < 6:             if a == 1:                 lst = lst1             elif a == 2:                 lst = lst2             elif a == 3:                 lst = lst3             elif a == 4:                 lst = lst4             elif a == 5:                 lst = lst5             if salary >= int(lst[2]):                 print(lst[1], '已经加入您的购物车，当前余额：', salary - int(lst[2]))                 salary = salary - int(lst[2])                 lst0.append(lst[1])                 lst0.append(lst[2])                 c += 1             else:                 print('余额不足，', salary - int(lst[2]))