通过导入外部文件来导入数据：

shop.txt

car    200000
iphone    4999
bicycle    500
cafe    35

##########################################################

python源代码：

#!/usr/bin/env python
# encoding=utf-8
# author:sihaogongyuan
# date:2015-4-9
# filename:shop.py
# desc:shop
####################################
import os
import sys
####################################
os.system('date')
product_list=[]
price_list=[]
shop_list=[]
####################################
f=file('shop.txt','r')
for line in f.readlines():
    new_line=line.split()
    product_list.append(new_line[0])
    price_list.append(int(new_line[1]))
####################################

salary=int(raw_input('\033[32mplease input your salary:\033[0m'))
####################################
while True:
    #pass
    print 'product list:'
    for p in product_list:
        p_index=product_list.index(p)
        p_price=price_list[p_index]
        print p,p_price
    choice=raw_input('please input your choice:')
    f_choice=choice.strip()
    while f_choice.strip=='':
        choice=raw_input('please input your choice:')
        f_choice=choice.strip()
    if f_choice in product_list:
        f_choice_index=product_list.index(f_choice)
        f_choice_price=price_list[f_choice_index]
        if salary>=f_choice_price:
            yes_or_no=raw_input('que ren goumai %s product?yes or no:'%(f_choice))
            if yes_or_no=='yes':
                print '\033[32m%s have add shop_list\033[0m'%(f_choice)
                shop_list.append(f_choice)
                salary=salary-f_choice_price
                print '\033[32m余额是:\033[0m',salary
            else:
                print '\033[32mcancle %s into gouwuche...\033[0m'%(f_choice)
                print '\033[32m余额是:\033[0m',salary
        else:
            if salary<min(price_list):
                print '\033[31mnot buy anything!!!!\033[0m'
                print '\033[32mgouwuche you:\033[0m',shop_list
                print '\033[32m余额是:\033[0m',salary
                sys.exit()
            else:
                print '\033[31m not afford %s,please try other\033[0m'%(f_choice)
                print '\033[32m余额是:\033[0m',salary

    else:
        print '\033[31m what you want is not founed,please try other\033[0m'