周末作业。二

  写一个购物车，可以注册。登录。购物。支付。充值：

import os
def register():
    tag = True
    while tag:
        name = input('请输入用户名>>:').strip()
        pwe = input('请输入密码>>:').strip()
        with open('ab.txt',mode='a+t',encoding='utf-8') as f:
            f.seek(0)
            for line in f:
                a = line.strip('\n').split(':')
                if name in a:
                    print('用户名已存在')
                    break
            else:
                info = '%s:%s\n'%(name,pwe)
                f.write(info)
                print('注册成功')
                tag = False
def login():
    tag = True
    dic = {}
    while tag:
        name = input('请输入用户名>>:').strip()
        pwe  = input('请输入密码>>:').strip()
        with open('ab.txt',mode='rt',encoding='utf-8') as read_f,\
                open('black.list.txt',mode='a+t',encoding='utf-8') as write_f:
            write_f.seek(0)
            for line in write_f:
                u = line.strip('\n')
                if u == name:
                    print('你已在黑名单内')
                    tag = True
                    break
            else:
                for line in read_f:
                    a = line.strip('\n').split(':')
                    if name == a[0]  and  pwe == a[1]:
                        print('登陆成功')
                        return name
                else:
                    print('密码输入错误')
                    read_f.seek(0)
                    for line in read_f:
                        a = line.strip('\n').split(':')
                        if name in a:
                            if name not in dic:
                                dic[name]=1
                            else:
                                dic[name]+=1
                            if dic[name]==3:
                                write_f.write('%s\n'%(name))
                                tag = False
                                break


def shopping():
    msg_dic={'alex':1,'egon':666,'iphoneX':12899,'mac':14899,}
    good_l=[]
    while True:
        for key,item in msg_dic.items():
            print('{name}     price:  {price}'.format(name=key,price=item))
        choice = input('请输入商品名>>:').strip()
        if not choice  or  choice not in msg_dic:
            print('商品名输入有误，请重新输入')
            continue
        count =input('请输入购买个数>>:').strip()
        if not count.isdigit():
            print('输入有误，请重新输入')
            continue
        count = int(count)
        good_l.extend([choice,msg_dic[choice],count,count*msg_dic[choice]])
        print(good_l)
        return good_l

def pay():
    with open('ab.txt',mode='rt',encoding='utf-8')as read_f,\
        open('cd.txt',mode='wt',encoding='utf-8') as write_f:
        for line in read_f:
            line = line.strip('\n').split(':')
            if name == line[0]:
                line[2]=int(line[2])
                good_l[3]=int(good_l[3])
                data=line[2]-good_l[3]
                if data < 0:
                    print('账户余额不足，请充值')
                    return
                print('购买成功,请继续选择')
                data = str(data)
                line[2] = str(line[2])
                line = ':'.join(line).replace(line[2],data)
                write_f.write('%s\n'%(line))
            else:
                line = ':'.join(line)
                write_f.write('%s\n'%(line))
    os.remove('ab.txt')
    os.rename('cd.txt','ab.txt')

def rec():
    with open('ab.txt',mode='rt',encoding='utf-8')as read_f,\
            open('cd.txt',mode='wt',encoding='utf-8')as write_f:
        for line in read_f:
            a = line.strip('\n').split(':')
            if name == a[0]:
                b = input('请输入你要充值的金额>>:').strip()
                if b.isdigit():
                    b = int(b)
                    if b<=0:
                        print('输入金额有误，请重新输入')
                    else:
                        print('充值成功')
                        a[2]=int(a[2])
                        data = a[2]+b
                        a[2]=str(a[2])
                        data=str(data)
                        a = ':'.join(a).replace(a[2],data)
                        write_f.write('%s\n'%(a))
            else:
                a = ':'.join(a)
                write_f.write('%s\n'%(a))
    os.remove('ab.txt')
    os.rename('cd.txt','ab.txt')

tag = True
while tag:
    print('''欢迎来到小吕通讯专卖店：
    1.注册
    2.登录
    3.退出''')
    choice = input('请选择你要用的功能>>:')
    if choice == '1':
        register()
    elif choice == '2':
        name=login()
        while tag:
            if name:
                print('''请先选择购物再进行支付，要不都报错！
    1.购物车
    2.支付
    3.充值
    4.退出''')
                choice = input('请选择>>:')
                if choice == '1':
                    good_l= shopping()
                elif choice == '2':
                    pay()
                elif choice == '3':
                    rec()
                elif choice == '4':
                    tag = False
    elif choice == '3':
        tag = False