购物车小程序

# 需求:
# 用户名和密码存放于文件中，格式为：egon|egon123
# 启动程序后，先登录，登录成功则让用户输入工资,然后打印商品列表，失败则重新登录，超过三次则退出程序
# 允许用户根据商品编号购买商品# 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
# 可随时退出，退出时，打印已购买商品和余额

#message.txt里的信息：

#seven|alex|egon
#dict = {'seven':'123', 'alex':'123', 'egon':'123'}

 

import ast
import time

with open('user_message.txt', mode='r+') as f:
    data = f.read()
messages = data.split('|')
# 准备创建字典到程序中
i = 0
dict1 = {}
dic = messages[len(messages) - 1]
dic = dic.strip('\n')
# dic是文件中的字典的数据
# print("dic=%s" % dic)
user_dic_1 = dic.split('=')
a = user_dic_1[len(user_dic_1) - 1].strip()
a = ast.literal_eval(a)
# print('user_dic = %s' % a, type(a))
# a是一个字典，存放了用户和对应的密码
user_count = {}
for k in a.keys():
    user_count[k] = 0
# print("user_count = %s" % user_count)
flag = 0
while flag == 0:
    name = input("请输入用户名：").strip()
    if not name == '':
        if name in a:
            pwd = input("请输入密码：").strip()
            if a[name] == pwd:
                print("登录成功！")
                flag = 1
            else:
                print("密码错误，请重新输入！")
                # 计数
                user_count[name] += 1
                print("该用户已输错%d次" % user_count[name])
                if user_count[name] >= 3:
                    flag = -1
        else:
            print("用户名不存在，请重新输入！")
    else:
        print("未输入数据，请重新输入！")
if flag == -1:
    print("尝试次数过多，已退出程序！")
msg_dic = {
    'apple': 10,
    'tesla': 100000,
    'mac': 3000,
    'Lenovo': 30000,
    'chicken': 10,
}
commodity_name = []
commodity_value = []
# commodity_name是记录商品名的列表
# commodity_value是商品对应的价格
for k in msg_dic:
    commodity_name.append(k)
for i in range(0, len(commodity_name)):
    x = msg_dic.get(commodity_name[i])
    commodity_value.append(x)
# print(commodity_name)
# print(commodity_value)


def print_messages():
    global msg_dic
    print('有如下商品：')
    for j in range(1, len(commodity_name) + 1):
        print("%d.%-8s 价格：%s" % (j, commodity_name[j - 1], commodity_value[j - 1]))
shopping_list = {}


def shopping_list_add(names, quantity):
    global shopping_list
    global commodity_name
    if names in shopping_list:
        shopping_list[names] += quantity
    else:
        shopping_list.setdefault(names, 1)


def show_shopping_list():
    print(shopping_list)

# 已经成功登录
while flag == 1:
    str_money = input("请输入工资：").strip()
    if str_money.isdigit():
        money = int(str_money)
        if money == 0:
            print("没工资怎么买东西啊，重新输入吧...")
        else:
            while flag == 1:
                print_messages()
                user_in = input("请输入要购买的商品编号，输入0可查看已购商品信息，输入-1可退出程序：").strip()
                if user_in == '':
                    print("未输入任何数据，请重新输入！")
                    time.sleep(1)
                    continue
                elif user_in == '-1':
                    user_in = -1
                elif not user_in.isdigit():
                    print("输入有误，请重新输入！")
                    time.sleep(1)
                    continue
                else:
                    user_in = int(user_in)
                # 开始执行编号对应的功能
                if user_in == -1:
                    flag = -1
                    if len(shopping_list) == 0:
                        print("用户未购买任何商品，总共花费是0，剩余金额是%d。" % money)
                    else:
                        print("购买了如下商品：")
                        show_shopping_list()
                        print("余额为%d" % money)
                    print("程序即将退出...")
                    time.sleep(1)
                elif user_in == 0:
                    # 打印已购商品信息
                    if len(shopping_list) == 0:
                        print("未购买任何商品！")
                        time.sleep(1)
                    else:
                        show_shopping_list()
                        time.sleep(1)
                elif 1 <= user_in <= len(commodity_name):
                    # 输入了正确的商品编号
                    user_in -= 1
                    # 购买的商品名
                    buy = commodity_name[user_in]
                    # 检测余额是否足够
                    if money < msg_dic[buy]:
                        print("余额不足！")
                        time.sleep(1)
                    else:
                        money -= commodity_value[user_in]
                        print("买了%s，余额为%d" % (buy, money))
                        # 往购物列表里加信息
                        shopping_list_add(buy, 1)
                        time.sleep(1)
                else:
                    print("输入有误，请重新输入！")
                    time.sleep(1)
    else:
        print("输入有误，请重新输入！")
        time.sleep(1)