购物车

import os
print('welcome!!')
product_list = [
    ['商品1',100],
    ['商品2',200],
    ['商品3',300],
    ['商品4',500],
    ['商品5',1000],
    ['商品6',3000],
    ['商品7',5000]]
current_user_info = []
membership_card = {}
shopping_cart = {}
db_file = r'dbfile.txt'
def myregistered():
    print('welcome!')
    member_name = input('please input your member name : ')
    with open(r'dbfile.txt', 'r', encoding='utf-8') as read_db_file:
        for line in read_db_file:
            db_user_info = line.strip('\n').split('|')
            if member_name in db_user_info:
                print("you are already a member!")
                return
    while True :
        password = input('please input your password : ')
        password2 = input('please input your password again: ')
        if password.isdigit() and password2.isdigit()  :
            password = int(password)
            password2 = int(password2)
        else :
            print('please try again !')
            continue
        if password == password2 :
            break
        else :
            continue
    Balance = input('please input how much do you want choice :')
    with open(r'dbfile.txt','a',encoding='utf-8') as write_db_file :
        write_db_file.write('%s|%s|%s\n'%(member_name,password,Balance))
    print('registration success!')
    c = input('Whether to log in now ? y/n')
    if c == 'y' :
        mylogin()
    else :
        pass

def  mylogin():
    n = 1
    while True :
        m_name = input('please input your Member name: ').strip()
        m_pwd = input('please input your password : ').strip()
        if n == 3 :
            print("Too many attempts !")
            b = input('do you want more try ? y/n')
            if b == 'y':
                n = 0
            else:
                print('Welcome to visit next time! ')
                return
        if m_pwd.isdigit():
            m_pwd = int(m_pwd)
        else :
            n += 1
            continue
        with open(r'dbfile.txt','r',encoding='utf-8') as read_db_file:
            for line in read_db_file :
                db_user_info = line.strip('\n').split('|')
        if m_name ==  db_user_info[0] and  m_pwd == int(db_user_info[1]):
            current_user_info.append(m_name)
            current_user_info.append(db_user_info[2])
            print('welcome! \n member name : %s \n Balance : %s '%(current_user_info[0],current_user_info[1]))
            print('login successful!')
            return
        else :
            print('mamber name or password is wrong! please try again!')
            n += 1
            continue
while True:
    print('1.shopping \n2.login \n3.registered\n4.Balance\n5.shopping_cart')
    d = input('make your choice pleace >>:')
    if d.isdigit():
        d = int(d)
        if d == 1:
                for index, product in enumerate(product_list):
                    print(index + 1, product)
                while True:
                        for index, product in enumerate(product_list):
                            print(index + 1, product)
                        choice = input('which one do you want ? >>>: ').strip()
                        if choice.isdigit():
                                choice = int(choice)
                                if choice < len(product_list) and choice >= 0:
                                    pname = product_list[choice - 1][0]
                                    pprice = product_list[choice - 1][1]
                                    if product_list[choice - 1][0] in shopping_cart:
                                        shopping_cart[pname]['count'] += 1
                                    else:
                                        shopping_cart[pname] = {'pprice': pprice, 'count': 1}
                                        # ([product_list[choice-1][0],product_list[choice-1][1],1])
                                    print(shopping_cart)
                        elif choice == 'q':
                            if current_user_info == []:
                                print('please login >> :')
                                mylogin()
                                for index, product in enumerate(product_list):
                                    print(index + 1, product)
                                print('已购买%s'%shopping_cart)
                                continue
                            elif current_user_info != []:
                                print(shopping_cart)
                                x = input('do you want to pay the bill? y/n')
                                if x == 'y' :
                                    t = 0
                                    for key in shopping_cart :
                                        t = t + shopping_cart[key]['count']*shopping_cart[key]['pprice']
                                    print('您一共消费%s'%t)
                                    if t < int(current_user_info[1]) :
                                        current_user_info[1] = int(current_user_info[1]) - t
                                        print('扣款成功，您的余额为%s'%current_user_info[1])
                                        with open(r'dbfile.txt','r',encoding='utf-8') as read_dbfile ,\
                                                open(r'dbfile.swap','w',encoding='utf-8') as write_dbfile:
                                                    for line in read_dbfile:
                                                        if line.startswith(current_user_info[0]):
                                                            l = line.strip('\n').split('|')
                                                            l[-1] = str(current_user_info[1])
                                                            line = '|'.join(l) + '\n'
                                                        write_dbfile.write(line)
                                        os.remove('dbfile.txt')
                                        os.rename('dbfile.swap', 'dbfile.txt')
                                        shopping_cart = {}
                                        continue
                                    else :
                                        print('sorry,钱不够')
                                        print(shopping_cart)
                                else :
                                    print(shopping_cart)
                                    for index, product in enumerate(product_list):
                                        print(index + 1, product)
        elif  d == 2:
            mylogin()
        elif d == 3:
            myregistered()
        elif d == 4:
            if current_user_info != []:
                print('Balance : %s '%current_user_info[1])
            else :
                print('please login !')
                mylogin()
        elif d == 5 :
            print(shopping_cart)
    else :
        print("plecse try again >>:")
        continue

# 必须先注册，后shopping  登陆，登陆时用户不存在没有提示注册