python实现简单的登陆验证

#!/usr/bin/env python
# _*_ coding:utf-8 _*_

'''
login program
if your faild 3th,your will be locked

输入用户名密码
认证成功后显示欢迎信息
输错三次后锁定


用户输入一次密码就写入到日志中去。记录成功或者失败状态。
每次登陆的时候先去看user_lock文件，然后再看login.log 文件
如果login.log文件里在三分钟内登陆一直失败过，那么会算上次数。

user_lock 文件的格式
hansz   2015-10-27 21:31:26.159738

'''
import getpass,datetime, time, os

# 设置锁定时间和错误次数
global error_time
error_time = 3
global count
count = 3

# 定义登陆成功函数
# 打印欢迎信息，并且写入登陆时间到日志中去。
def login_succeed(user_name):
    print "欢迎您，尊敬的 %s" % user_name
    now_time = str(datetime.datetime.now())
    with open("session.log", "a") as f:
        login_info = "%s    login succeed in    %s \n" % (user_name, now_time.split(".")[0])
        f.write(login_info)
    return True

# 定义登陆失败函数
# 每次调用都会传入登陆次数，每次都会减1.
# 超过三次就写入到锁文件中去。
def login_failed(user_name, count):
    count = count - 1
    if count > 0:
        print "(密码输入错误，您还有%d次机会)" % count
        user_passwd = raw_input("请输入密码：")
        if_passwd_ok(user_name, user_passwd, count)
    else:
        print "错误次数超过三次，已锁定账号"
        os.system("sed -i '/%s/d' user_lock" % user_name)
        lock_time = str(datetime.datetime.now())
        with open("user_lock", "a")as f:
            lock_info = "%s %s\n" % (user_name, lock_time.split(".")[0])
            f.write(lock_info)
        with open("session.log", "a")as f:
            faild_info = "%s    are locked in   %s \n " % (user_name, lock_time.split(".")[0])
            f.write(faild_info)

# 把用户和登陆时间写入到锁用户文件中去
def user_lock(user_name, login_time):
    with open("user_lock", "a") as f:
        lock_user = "%s/n" % user_name
        f.write(lock_user)


# 把字符串格式的时间转换为datetime格式
def str_to_date(str_date):
    date_date = datetime.datetime.fromtimestamp(time.mktime(time.strptime(str_date, "%Y-%m-%d %H:%M:%S")))
    return date_date

# 用于比较登陆时间和锁定时间
# 时间超过error_time之后 返回true
def date_compare(str_date_old, str_date_new):
    print "您现在登陆的时间是%s" % str_date_new
    date_date_new = str_to_date(str_date_new)
    date_date_old = str_to_date(str_date_old)
    diff = (date_date_new - date_date_old)
    diff_str = str(diff)
    # print "这个是时间差",int(diff_str.split(":")[0]),int(diff_str.split(":")[1])
    if int(diff_str.split(":")[0]) == 0:
        if int(diff_str.split(":")[1]) >= error_time:
            return True
        else:
            return False
    elif int(diff_str.split(":")[0]) > 0:
        return True
    else:
        return False


# 判断密码是否正确
def if_passwd_ok(user_name, user_passwd, count):
    if count > 0:
        # 从用户列表里面读取用户名和密码
        status0 = 0
        with open("user.list", 'r')as f:
            for i in f.readlines():
                # 如果用户名密码正确
                if i.split()[1] == user_name:
                    if i.split()[2] == user_passwd:
                        login_succeed(user_name)
                        status0 = 1
                        break
                    else:
                        login_failed(user_name, count)
                        status0 = 1
                        break
            if status0 == 0:
                print "没有这个用户"
    else:
        print "账号被锁定啦。"


# 从登陆日志查看是否近三分钟登陆过且登陆失败了
# 判断是否被锁定
def if_lock(user_name, user_passwd, login_time):
    # 读取user_lock 文件
    status1 = 0
    with open("user_lock", 'r') as f:
        content = f.readlines()
        if content == []:
            if_passwd_ok(user_name, user_passwd, count)
        else:
            for i in content:
                # 如果用户名存在在列表当中
                if i.split()[0] == user_name:
                    # 查看写入lock文件时的时间，如果超过三分钟就把他删除，如果没有超过三分钟，就拒绝登陆
                    date_old = "%s %s" % (i.split()[1], i.split()[2])
                    if date_compare(date_old, login_time):
                        if_passwd_ok(user_name, user_passwd, count)
                        # 删除用户。用linux下的sed
                        os.system("sed -i '/%s/d' user_lock" % user_name)

                        status1 = 1
                        break
                    # 删除用户
                    else:
                        print  "您在三分钟之内登录三次错误，已被锁定，请稍后再试。"
                        status1 = 1
                        break
                else:
                    continue
            if status1 == 0:
                if_passwd_ok(user_name, user_passwd, count)


# datetime.datetime.fromtimestamp(time.mktime(time.strptime(stringDate,"%Y-%m-%d %H:%M:%S")))





print "欢迎登陆系统".center(100)
user_name = raw_input("请输入用户名：")
#user_passwd=raw_input("enter your passwd")
user_passwd = getpass.getpass("请输入密码：")
d1 = datetime.datetime.now()
login_time = str(d1).split(".")[0]
if_lock(user_name, user_passwd, login_time)