作业 3/16

1、通用文件copy工具实现

with open('users.txt','rb') as f1,open('users1','wb') as f2:
    for i in f1:
        f2.write(i)

2、基于seek控制指针移动，测试r+、w+、a+模式下的读写内容

with open('users.txt','r+',encoding='utf-8') as f1:
    print(f1.read())
    f1.seek(0,0)
    print(f1.read())
with open('users.txt','w+',encoding='utf-8') as f2:
    f2.write('egon/alex')
    f2.seek(0,0)
    print(f2.read())
with open('users.txt','a+',encoding='utf-8') as f3:
    print(f3.read())
    f3.seek(0,0)
    print(f3.read())

3、tail -f access.log程序实现

with open(r'D:python之路users.txt','rb') as f:
    f.seek(0,2)
    while True:
        a = f.tell()
        while True:
            f.seek(a,0)
            l = f.read()
            if l:
                print(l.decode('utf-8'))
                break
            else:
                continue

4、周末作业参考在老师讲解完毕后（下午17：30开始讲解），练习熟练，明早日考就靠他俩
4.1：编写用户登录接口

user = input('请输入账号：')
pwd = input('请输入密码：')
with open('users1','r',encoding='utf-8') as f:
    for line in f:
        user1, pwd1 = line.strip().split(':')
        if user1 == user and pwd1 == pwd:
            print('登陆成功')
            break
    else:
        print('登录失败')

4.2：编写程序实现用户注册后（注册到文件中），可以登录（登录信息来自于文件）

while True:
    user = input('请输入账号：').strip()
    pwd = input('请输入密码：').strip()
    pwd1 = input('确认密码：').strip()
    if user:
        if pwd == pwd1:
            with open('users.txt','a',encoding='utf-8') as f:
                f.write('{}:{}
'.format(user,pwd))
            print('注册成功')
            break
        else:
            print('密码不一致')
    else:
        print('账号不能为空')
tag = True
while tag:
    name = input('请输入账号：').strip()
    pwd5 = input('请输入密码：').strip()
    with open('users.txt','r',encoding='utf-8') as f1:
        for line in f1:
            name1, pwd0 = line.strip().split(':')
            if name == name1 and pwd0 == pwd5:
                print('登陆成功')
                tag = False
                break
        else:
            print('登陆失败')