购物车

goods = [
{"name": "电脑", "price": 1999},
{"name": "鼠标", "price": 10},
{"name": "游艇", "price": 20},
{"name": "美女", "price": 998},
......
]
功能要求：
1、启动程序后，输入用户名密码后，让用户输入工资，然后打印商品列表
2、允许用户根据商品编号购买商品
3、用户选择商品后，检测余额是否够，够就直接扣款，不够就提醒
4、可随时退出，退出时，打印已购买商品和余额
5、在用户使用过程中， 关键输出，如余额，商品已加入购物车等消息，需高亮显示

扩展需求：
1、用户下一次登录后，输入用户名密码，直接回到上次的状态，即上次消费的余额什么的还是那些，再次登录可继续购买
2、允许查询之前的消费记录

3、用户可以添加商品

#!/usr/bin/env python3
#-*- coding:utf-8 -*-
'''
Time:2018/5/4 18:11
File:购物车优化
'''


exit_flag = False

goods = [
{"name": "电脑", "price": 1999},
{"name": "鼠标", "price": 10},
{"name": "游艇", "price": 20},
{"name": "美女", "price": 998},
]

shopping = []
name = input('请输入您的账号：').strip()
f = open('black_file.txt','r',encoding='utf-8')
lock_file = f.read()# 读取黑名单文件
f.close()
if name in  lock_file:# 如果账户在黑名单文件里，账户将被锁定
    print('账户被锁定,请联系管理员！')
    exit()

cont = 0
with open('b.txt', 'r', encoding='utf-8') as f:
        yi = eval(f.read())

while cont < 3:
    if name not in yi['name']:
        print('账号不存在，请注册下你的账号！')
        name1 = input('请输您的账号：').strip()
        passwd1 = input('请输入您的密码：').strip()
        while True:
            salary = input('请输入您的工资：').strip()
            if salary.isdigit():
                salary = int(salary)
                break
            else:
                print('输入错误')
                continue
        lis = {'name': name1, 'passwd': passwd1, 'salary': salary}
        with open('b.txt', 'w', encoding='utf8') as f:
                f.write(str(lis))
                break
    else:
        passwd = input('请输入您的密码：').strip()
        if name == yi['name'] and passwd == yi['passwd']:
            print('欢迎回来33[31;1m%s33[0m,您的余额还有33[31;1m%s33[0m'%(name,yi['salary']))
            shopping_list = input("是否要读取上一次购物历史|y|n|：").strip()
            if shopping_list == 'y':
                with open('a.txt','r',encoding='utf8') as f:
                    f1 = eval(f.read())
                    for i,v in enumerate(f1):
                        print(v['name'],v['price'])
                    shopping1 = input('是否要继续购物|y|n：').strip()
                    if shopping1 == 'y':
                        pass
                    else:
                        exit()
                    break
            elif shopping_list == 'n':
               break
            else:
                print('输入错误！')
                continue
        else:
            print('账号密码错误！')
    cont += 1

if cont == 3:
    print('对不起，密码输错三次，账户被锁定！')
    f = open('black_file.txt', 'a+')
    f.write('%s
' % name)  # 密码输入三次将账户写入到黑名单文件里
    f.close()
    exit()



while not exit_flag:
    print('-----------商品列表-------')
    for i,v in enumerate(goods):
        print(i,v['name'],v['price'])

    choice = input('请输入商品的编号或输入q退出！|a添加商品：').strip()

    if choice.isdigit():
        choice = int(choice)
        if choice >= 0 and choice < len(goods):
            product = goods[choice]
            print(product['price'])
            if  product['price'] <= yi['salary']:
                shopping.append(product)
                yi['salary'] -= product['price']
                with open('b.txt','w',encoding='utf8') as f:
                    f.write(str(yi))
                print('商品33[31;1m%s33[0m已加入购物车，您的余额还有33[31;1m%s元33[0m'%(goods[0]['name'],yi['salary']))
            else:
                print('对不起，您的余额不足，无法购买！')
            # print(shopping)
        else:
            print('商品不存在，请重新输入！')

    elif choice == 'q' or choice == 'Q':
        # print(shopping)
        if len(shopping) > 0:
            print('-----已购买的商品-------')
            print('ID 商品 价格')
            for i,v in enumerate(shopping):
                print('%s.  %s %s'%(i,v['name'],v['price']))
            print('您的余额还剩33[31;1m%s33[0m'%yi['salary'])
            with open('a.txt','w',encoding='utf-8') as f:
                f.write(str(shopping))
            # print(shopping)
            exit_flag = True
    elif choice == 'a':
        print('添加商品')
        print('已有商品')
        for i,v in enumerate(goods):
            print(i,v['name'],v['price'])

        a = input('商品名称：').strip()
        a1 = int(input('商品价格：').strip())
        dic = {'name':a,'price':a1}

        goods.append(dic)

        print('商品已添加完成')
        for i,v in enumerate(goods):
            print(i,v['name'],v['price'])