用函数完成登录注册以及购物车的功能。
1，启动程序，用户可选择四个选项：登录，注册，购物，退出。
2，用户注册，用户名不能重复，注册成功之后，用户名密码记录到文件中
用户名的要求是只能含有字母数字不能含有特殊字符。
密码的要求是长度不能超过14个字符。
3，用户登录，用户名密码从文件中读取，进行三次验证，验证不成功则退出整个程序。
4，用户登录成功之后才能选择购物功能进行购物，购物功能：
购物车的要求：
1，将购物车封装到一个函数中。
2，在上周的基础上，可以实现充值的拓展，以及其他相关拓展。
3，用户选择退出购物车时，将已购买的商品记录到一个文件中，将未付钱的但加入购物车的商品记录到一个文件中。
4,每个用户专属两个文件，一个文件（文件名：登录的用户名_buy_goods）存储已购买的商品，另一个文件（文件名：登录的用户名_want_buy）存储加入购物车但没有购买的文件。(升级功能)
5,给购物车增加两个功能：1，可查看已购买的商品。2可查看上次退出时加入购物车未购买的商品。(升级功能)
6，对于第5题的第二个功能可以进行购买商品并追加到已购买的文件中。(升级功能)
5，退出则是退出整个程序。
def regist():
flag = True
while flag:
username = input('Please input your regist name(only characters or digits): ').strip()
if username.isalnum():
with open('Regist Information', encoding='utf-8', mode='r+') as f:
lis = f.readlines()
for i in lis:
if username == i.split('|')[0].strip():
print('Username is already exist,enter another one!')
else:
password = input('Input your password,lenth of the password is less than 15:')
if len(password) < 15:
f.write('{:<20} | {:<20}\n'.format(username, password))
print('Success Regist!')
flag = False
break
else:
print('Lenth of password is less than 15,enter your password again!')
else:
print('Username only contains characters or digits, please enter another username!')
def login():
n = 0
flag = True
while flag and n < 3:
username = input('Please input your username:').strip()
password = input('Please input your password:').strip()
with open('Regist Information', encoding='utf-8', mode='r') as f:
lis = f.readlines()
for i in lis:
if username == i.split('|')[0].strip() and password == i.split('|')[1].strip():
print('Successful Login!')
flag = False
return username
else:
print('Wrong username or password,please enter again!')
n += 1
def shop_car():
goods = [{"name": "Dior Lipstick Colour 999", "price": 280},
{"name": "Mac Blush Colour 054", "price": 220},
{"name": "Urbandecay Eyeshadow Naked 3", "price": 370},
{"name": "Mac Blush Colour 584", "price": 140},
{"name": "Makeup Forever Brush 846", "price": 110},
{"name": "Chennal Perfume 864", "price": 590},
{"name": "Lancon Perfume Rose", "price": 650}]
dic_money = {'余额': 0}
print('欢迎光临，您现有余额为: {}元'.format(dic_money['余额']))
money = float(input('请输入你要充值的金额: ').strip())
dic_money['余额'] = dic_money['余额'] + money
print('您充值之后现有余额为: {}元'.format(dic_money['余额']))
print('商品列表'.center(20, '-'))
for i in range(len(goods)):
print(i + 1, '\t', goods[i]['name'], '\t', goods[i]['price'])
print('b 购物车结算')
print('-' * 20)
goods_price = {}
for i in range(len(goods)):
goods_price[(goods[i]['name'])] = goods[i]['price']
shop_carc = {}
shop_carp = {}
shop_list = []
while 1:
n = input('input your choice(1- {}) or input q(Q) to quit: '.format(len(goods))).strip()
command = n
if n.isdigit():
if int(n) <= len(goods): # 打印商品名称及商品价格,并将此商品，添加到购物车，用户还可继续添加商品
shop_name = goods[int(n) - 1]['name']
shop_price = goods[int(n) - 1]['price']
print('您本次选择的商品名称：{}，价格：{}元'.format(shop_name, shop_price))
shop_list.append(shop_name)
shop_carc[shop_name] = shop_list.count(shop_name)
shop_carp[shop_name] = shop_carc[shop_name] * goods_price[shop_name]
print('\n' + '------您已选择的各商品清单-------' + '\n')
for item in shop_carc.items():
if shop_carc[item[0]] > 0:
print('名称--{} , 总数量--{}，总价格--{}元'.format(item[0], shop_carc[item[0]], shop_carp[item[0]]))
else:
print('输入有误，请重新输入')
else:
if command.lower() == 'y': # 依次显示用户购物车里面的商品，数量及单价
print('您最终购买的商品'.center(20, '-'))
for key in shop_carc.keys():
print('商品：{}，数量：{}，价格：{}元'.format(key, shop_carc[key], shop_carp[key]) + '\n')
print('-' * 30)
break
elif command.lower() == 'q':
break
else:
print('输入有误，请重新输入')
import os
while 1:
choice = input('Please input your choice（login:l(L), regist:r(R)').strip()
if choice.upper() == 'L':
username = login()
filenames = os.walk(r'D:\userIfo')[2]
buy_goods = buy[0]
want_buy_goods =
if '{}_buy_goods'.format(username) not in filenames:
with open('{}_buy_goods'.format(username), encoding='utf-8', mode='w') as f:
f.write('{}\n'.format(buy_goods))
else:
with open('{}_buy_goods'.format(username), encoding='utf-8', mode='a+') as f:
f.write('{}\n'.format(buy_goods))
if '{}_buy_goods'.format(username) not in filenames:
with open('{}_want_buy'.format(username), encoding='utf-8', mode='w') as f:
f.write('{}\n'.format(want_buy_goods))
else:
with open('{}_want_buy'.format(username), encoding='utf-8', mode='a+') as f:
f.write('{}\n'.format(want_buy_goods))
choice2 = input('Please input your choice(buy:b（B），quit:q(Q）').strip()
if choice.upper() == 'B':
pass
elif choice.upper() == 'Q':
break
else:
print('Wrong input，Please enter the right choice!')
elif choice.upper() == 'R': # 注册功能
regist()
else: print('Wrong input，please input right choice')