Python - 购物车代码 (账户登陆，用户个人清单存取，重要信息高亮显示)

• 需要掌握open函数。
• 清单存取时，需要注意编码问题，直接在读取和存储时加上encoding = 'utf - 8' 可以解决gbk - unicode转化时出现的乱码问题。

# _*_coding:utf-8_*_

import os

FILE_PATH = 'save.txt'

# Database
div = {
    'user1': {'password': '123'},
    'user2': {'password': '123'},
    'user3': {'password': '123'},
}
goods = [
    {"name": "电脑", "price": 1999},
    {"name": "鼠标", "price": 10},
    {"name": "游艇", "price": 20},
    {"name": "美女", "price": 998},
]

# 读取用户购买信息 save_cart->exist [username as keys]
save_cart = {}
if os.path.exists(FILE_PATH):
    with open(FILE_PATH, mode="r", encoding='utf-8') as f:
        for line in f.readlines():
            save_cart.update(eval(line.strip()))

# login loop name->exist
while True:
    name = input("登录用户名:").strip()
    if name == 'q':
        exit('Bye.')
    if name not in div:
        print("用户名错误")
    if name in div:
        password = input("请输入密码:").strip()
        if password == div[name]['password']:
            print("欢迎回来，%s！" % name)
            break
        else:
            print("密码错误")

# money->exist lst->exist
a = save_cart.get(name)
if a is not None:
    money = a.get('m')
    lst = a.get('ls')
    print('-------已购买-------')
    print('您的余额为￥', money)
    for index, p in enumerate(lst):
        print('%s. %s %s' % (index, p[0], p[1]))
else:
    money = int(input('Please input your salary:'))
    lst = []

#shopping loop
while True:
    print("--------商品列表---------")
    for index, p in enumerate(goods):
        print("%s. %s %s" % (index, p.get('name'), p.get('price')))
    choice = input("输入想买的商品编号:")
    if choice.isdigit():
        choice = int(choice)
        if choice >= 0 and choice < len(goods):
            if money > goods[choice].get('price'):
                money -= goods[choice].get('price')
                lst.append([goods[choice]['name'], goods[choice]['price']])
                print("Added product \033[31;1m%s,￥%s\033[0m into shopping cart." % (
                goods[choice].get('name'), goods[choice].get('price')))
            else:
                print("余额不足。")
        else:
            print("商品不存在")
    elif choice == 'q':
        if len(lst) > 0:
            print("-------你已购买以下商品-------")
            for index, p in enumerate(lst):
                print("%s. %s ￥%s" % (index, p[0], p[1]))
            print("你的余额为：\033[31;1m%s\033[0m" % money)
        break
    elif choice == 'd':
        if len(lst) > 0:
            print("-------你已购买以下商品-------")
            for index, p in enumerate(lst):
                print("%s. %s ￥%s" % (index, p[0], p[1]))
        print("你的余额为：\033[31;1m%s\033[0m" % money)

# save 2 file
with open(FILE_PATH, mode='w', encoding='utf-8') as f:
    save_cart.update({name: {'m': money, 'ls': lst}})
    # {'user1': {'m': 0, 'ls': []}}
    f.write(str(save_cart))