python全栈系列之---定义一个session类

            #self.get_secure_cookie()
            #The decoded cookie value is returned as a byte string (unlike
            #`get_cookie`).

        import hashlib
        import time
        obj = hashlib.md5()
        obj.update(bytes(str(time.time()), encoding="utf8"))#传入byte类型
        random_str = obj.hexdigest()#返回字符串
        """ Return the digest value as a string of hexadecimal digits. """

import tornado.web

#放在内存 redis  文件  数据库
container={}

#定义一个session类
class Session:
    def __init__(self,handler):
        self.handler=handler
        pass

    def __genarate_random_str(self):
        import hashlib
        import time
        obj = hashlib.md5()
        obj.update(bytes(str(time.time()), encoding="utf8"))#传入byte类型
        random_str = obj.hexdigest()#返回字符串
        return random_str

    def set_value(self,key,value):
        #在container中加入随机字符串
        #加入自定义数据
        #在客户端中写入随机字符串
        random_str=‘‘
        if self.handler.get_cookie(‘py_session‘):
            random_str=self.handler.get_cookie(‘py_session‘)
            if not container.get(random_str,None):
                random_str = self.__genarate_random_str()
        else:
            random_str=self.__genarate_random_str()
        if not container.get(random_str,None):
            container[random_str]={}
        container[random_str][key]=value
        #加入客户端
        self.handler.set_cookie(‘py_session‘,random_str)


    def get_value(self,key):
        #先去获取客户端的随机字符串
        #从container中获取自定义数据
        random_str=self.handler.get_cookie(‘py_session‘,None)
        dict_info=container.get(random_str,None)
        if not dict_info:
            return None
        return dict_info[key]

class IndexHandler(tornado.web.RequestHandler):
    def get(self):
        if self.get_argument(‘u‘,None) in [‘asd‘,‘zxc‘]:
            s = Session(self)
            s.set_value(‘is_login‘,True)
            #self.get_secure_cookie()
            #The decoded cookie value is returned as a byte string (unlike
            #`get_cookie`).

        else:
            self.write("请登录")

class ManagerHandler(tornado.web.RequestHandler):
    def get(self, *args, **kwargs):
        s=Session(self)
        val = s.get_value(‘is_login‘)
        if val:
            self.write("登录成功")
        else:
            self.redirect("/index")


settings ={
    ‘template_path‘:‘views‘,
    ‘static_path‘:‘statics‘,
    ‘cookie_secret‘:‘dafawafawfaw‘,
}

application = tornado.web.Application([
    (r"/index",IndexHandler),
    (r"/manager",ManagerHandler),
],**settings)