优化后的标题：构建简易在线购物车系统的用户登录与购物流程

注释掉的是每天都敲的任务&＃xff0c;下面的是自己没事写的&＃xff0c;特别的简单的&＃xff0c;根据自己学的写的。

# menu &＃61; {
# &＃39;北京&＃39;: {
# &＃39;海淀&＃39;: {
# &＃39;五道口&＃39;: {
# &＃39;soho&＃39;: {},
# &＃39;网易&＃39;: {},
# &＃39;google&＃39;: {}
# },
# &＃39;中关村&＃39;: {
# &＃39;爱奇艺&＃39;: {},
# &＃39;汽车之家&＃39;: {},
# &＃39;youku&＃39;: {},
# },
# &＃39;上地&＃39;: {
# &＃39;百度&＃39;: {},
# },
# },
# &＃39;昌平&＃39;: {
# &＃39;沙河&＃39;: {
# &＃39;老男孩&＃39;: {},
# &＃39;北航&＃39;: {},
# },
# &＃39;天通苑&＃39;: {},
# &＃39;回龙观&＃39;: {},
# },
# &＃39;朝阳&＃39;: {},
# &＃39;东城&＃39;: {},
# },
# &＃39;上海&＃39;: {
# &＃39;闵行&＃39;: {
# "人民广场": {
# &＃39;炸鸡店&＃39;: {}
# }
# },
# &＃39;闸北&＃39;: {
# &＃39;火车战&＃39;: {
# &＃39;携程&＃39;: {}
# }
# },
# &＃39;浦东&＃39;: {},
# },
# &＃39;山东&＃39;: {},
# }
# tag &＃61; True
# while tag:
# menu1 &＃61; menu
# for key in menu1:
# print(key)
# choicel &＃61; input(&＃39;第一层&＃xff1a;>>&＃39;).strip()
#
# if choicel &＃61;&＃61; &＃39;b&＃39;:
# print(&＃39;到顶了&＃xff0c;你得选择下面的&＃xff1a;&＃39;)
# continue
# if choicel &＃61;&＃61; &＃39;q&＃39;:
# tag &＃61; False
# continue
# if choicel not in menu1:
# print(&＃39;输错了&＃39;)
# continue
#
# while tag:
# menu2 &＃61; menu1[choicel]
# for key in menu2:
# print(key)
#
# choicel &＃61; input(&＃39;第二层&＃xff1a;>>&＃39;).strip()
#
# if choicel &＃61;&＃61; &＃39;b&＃39;:
# break
# if choicel &＃61;&＃61; &＃39;q&＃39;:
# tag &＃61; False
# continue
# if choicel not in menu2:
# print(&＃39;输错了&＃39;)
# continue
#
# while tag:
# menu3 &＃61; menu2[choicel]
# for key in menu3:
# print(key)
# choicel &＃61; input(&＃39;第三层&＃xff1a;>>&＃39;).strip()
#
# if choicel &＃61;&＃61; &＃39;b&＃39;:
# break
# if choicel &＃61;&＃61; &＃39;q&＃39;:
# tag &＃61; False
# continue
# if choicel not in menu3:
# print(&＃39;输错了&＃39;)
# continue
#
# while tag:
# menu4 &＃61; menu3[choicel]
# for key in menu4:
# print(key)
# choicel &＃61; input(&＃39;第四层&＃xff1a;>>&＃39;).strip()
# if choicel &＃61;&＃61; &＃39;q&＃39;:
# tag &＃61; False
# continue
# if choicel &＃61;&＃61; &＃39;b&＃39;:
# break
# if choicel not in menu4:
# print(&＃39;输错了&＃39;)
# continue
product_list &＃61; [[&＃39;Iphone7&＃39;, 5800],[&＃39;Coffee&＃39;, 30],[&＃39;疙瘩汤&＃39;, 10],[&＃39;Python Book&＃39;, 99],[&＃39;Bike&＃39;, 199],[&＃39;ViVo X9&＃39;, 2499],
]
name_list &＃61; []
menu_dic &＃61; {}
buy_list &＃61; []
username_pwd &＃61; [{&＃39;xxx&＃39;: &＃39;12&＃39;}, {&＃39;rui&＃39;: &＃39;222&＃39;}]
# pwd &＃61; &＃39;123&＃39;
count &＃61; 0
tag3 &＃61; True
tag2 &＃61; True
tag1 &＃61; True
tag &＃61; True
sum_price &＃61; 0
while tag2:print(&＃39;{:-^20}&＃39;.format(&＃39;>登录<&＃39;))print(&＃39;{:-^20}&＃39;.format(&＃39;>注册<&＃39;))print(&＃39;{:-^20}&＃39;.format(&＃39;如果没有账号请注册&＃39;))choose_login_register &＃61; input("请选择你要进行的操作:>>").strip()if choose_login_register &＃61;&＃61; &＃39;登录&＃39;:while tag1:inp_username &＃61; input(&＃39;请输入用户名:&＃39;).strip()inp_pwd &＃61; input(&＃39;请输入密码:&＃39;).strip()if {inp_username: inp_pwd} in username_pwd:while tag:for i in product_list:x, y &＃61; imenu_dic[x] &＃61; yname_list.append(x)print(f&＃39;商品名&＃xff1a;{x}--&＃xffe5;:{y}&＃39;)print(f&＃39;购物车里面的商品&＃xff1a;{buy_list}&＃39;)choose &＃61; input(&＃39;将你想要的添加到购物车&＃xff1a;>>&＃39;).strip()if choose &＃61;&＃61; &＃39;结算&＃39;:# tag &＃61; Falsebreakif choose in name_list:buy_list.append(choose)else:print(&＃39;请输入正确的商品名&＃39;)continuefor j in buy_list:sum_price &＃61; sum_price &＃43; int(menu_dic[j])print(f&＃39;您需要支付:&＃xffe5;{sum_price}元&＃39;)# zhifubao &＃61; input("请输入您的支付宝账户").strip()tag1 &＃61; Falsecontinueelse:if count &＃61;&＃61; 2:print(&＃39;没次数了&＃39;)breakprint(f&＃39;输入错误&＃xff0c;你还有{2 - count}次机会&＃39;)count &＃43;&＃61; 1elif choose_login_register &＃61;&＃61; &＃39;注册&＃39;:while tag3:username_pwd_cop &＃61; username_pwd.copy()for k in username_pwd:if len(username_pwd_cop) >").strip()for xc_key, xc_value in k.items():if xc_key &＃61;&＃61; user_register:print("已存在用户名&＃xff0c;请重新输入")breakelse:pwd_register &＃61; input("请输入密码:>>").strip()pwd_register_again &＃61; input("请再次输入密码:>>").strip()if pwd_register &＃61;&＃61; pwd_register_again:username_pwd.append({user_register: pwd_register})print(&＃39;注册成功&＃xff01;&＃39;)breakelse:print(&＃39;两次输入不一样&＃39;)continueelif choose_login_register &＃61;&＃61; &＃39;q&＃39;: # 不想登录输入qbreakelse:print("您输入错误的选项辣&＃xff01;")