知识点： 文件读，写操作，if 判断， for 循环
salary = input(“输入你的工资：”)
bought_list = []
product_list = {}
with open(“product_list”,”r”,encoding=”utf-8″) as f1:
for item in f1:
p_name,p_price = item.strip().split(‘:’)
product_list[p_name]=int(p_price)
print(product_list)
if salary.isdigit():
salary = int(salary)
while true:
user_choice = input(“please input product which you want:”)
if user_choice in product_list.keys():
if product_list[user_choice]