flask session

1. Flask自带的session功能

from flask import session
import json
app=Flask(__name__,template_folder='templates',static_path='/static/',static_url_path='/static/')
app.debug=True
app.secret_key='sjehfjeefrjewth43u'  #设置session加密
app.config['JSON_AS_ASCII']=False  #指定json编码格式 如果为False 就不使用ascii编码，
app.config['JSONIFY_MIMETYPE'] ="application/json;charset=utf-8" #指定浏览器渲染的文件类型，和解码格式；

@app.route('/login/',methods=['GET','POST'])
def login():
    msg = ''
    if request.method=='POST':
        name=request.values.get('user')
        pwd=request.values.get('pwd')
        if name =='zhanggen' and pwd=='123.com':
            session['user']=name  #设置session的key value
            return redirect('/index/')
        else:
            msg='用户名或者密码错误'
    return render_template('login.html',msg=msg)

@app.route('/index/',methods=['GET','POST'])
def index():
    user_list = ['张根', 'egon', 'eric']
    user=session.get('user')           #获取session
    if user:
        user=['alex','egon','eric']
        return jsonify(user_list)
    else:
        return redirect('/login/')

if __name__ == '__main__':
    app.run()

2.第三方session组件（Session）

安装 pip install flask-session

from flask import session, Flask,request,make_response,render_template,redirect,jsonify,Response

from flask.ext.session import Session #引入第三方session
import json
app=Flask(__name__,template_folder='templates',static_path='/static/',static_url_path='/static/')
app.debug=True
app.secret_key='sjehfjeefrjewth43u'  #设置session加密
app.config['JSON_AS_ASCII']=False  #指定json编码格式 如果为False 就不使用ascii编码，
app.config['JSONIFY_MIMETYPE'] ="application/json;charset=utf-8" #指定浏览器渲染的文件类型，和解码格式；

app.config['SESSION_TYPE']='redis'

from redis import Redis        #引入连接 redis模块
app.config['SESSION_REDIS']=Redis(host='192.168.0.94',port=6379) #连接redis
Session(app)

@app.route('/login/',methods=['GET','POST'])
def login():
    msg = ''
    if request.method=='POST':
        name=request.values.get('user')
        pwd=request.values.get('pwd')
        if name =='zhanggen' and pwd=='123.com':
            session['user']=name  #设置session的key value
            return redirect('/index/')
        else:
            msg='用户名或者密码错误'
    return render_template('login.html',msg=msg)

@app.route('/index/',methods=['GET','POST'])
def index():
    user_list = ['张根', 'egon', 'eric']
    user=session.get('user')           #获取session
    if user:
        user=['alex','egon','eric']
        return jsonify(user_list)
    else:
        return redirect('/login/')

if __name__ == '__main__':
    app.run()

不仅可以把session存放到redis还可放到文件、内存、memcache...

    def _get_interface(self, app):
        config = app.config.copy()
        config.setdefault('SESSION_TYPE', 'null')
        config.setdefault('SESSION_PERMANENT', True)
        config.setdefault('SESSION_USE_SIGNER', False)
        config.setdefault('SESSION_KEY_PREFIX', 'session:')
        config.setdefault('SESSION_REDIS', None)
        config.setdefault('SESSION_MEMCACHED', None)
        config.setdefault('SESSION_FILE_DIR',
                          os.path.join(os.getcwd(), 'flask_session'))
        config.setdefault('SESSION_FILE_THRESHOLD', 500)
        config.setdefault('SESSION_FILE_MODE', 384)
        config.setdefault('SESSION_MONGODB', None)
        config.setdefault('SESSION_MONGODB_DB', 'flask_session')
        config.setdefault('SESSION_MONGODB_COLLECT', 'sessions')
        config.setdefault('SESSION_SQLALCHEMY', None)
        config.setdefault('SESSION_SQLALCHEMY_TABLE', 'sessions')

        if config['SESSION_TYPE'] == 'redis':
            session_interface = RedisSessionInterface(
                config['SESSION_REDIS'], config['SESSION_KEY_PREFIX'],
                config['SESSION_USE_SIGNER'], config['SESSION_PERMANENT'])
        elif config['SESSION_TYPE'] == 'memcached':
            session_interface = MemcachedSessionInterface(
                config['SESSION_MEMCACHED'], config['SESSION_KEY_PREFIX'],
                config['SESSION_USE_SIGNER'], config['SESSION_PERMANENT'])
        elif config['SESSION_TYPE'] == 'filesystem':
            session_interface = FileSystemSessionInterface(
                config['SESSION_FILE_DIR'], config['SESSION_FILE_THRESHOLD'],
                config['SESSION_FILE_MODE'], config['SESSION_KEY_PREFIX'],
                config['SESSION_USE_SIGNER'], config['SESSION_PERMANENT'])
        elif config['SESSION_TYPE'] == 'mongodb':
            session_interface = MongoDBSessionInterface(
                config['SESSION_MONGODB'], config['SESSION_MONGODB_DB'],
                config['SESSION_MONGODB_COLLECT'],
                config['SESSION_KEY_PREFIX'], config['SESSION_USE_SIGNER'],
                config['SESSION_PERMANENT'])
        elif config['SESSION_TYPE'] == 'sqlalchemy':
            session_interface = SqlAlchemySessionInterface(
                app, config['SESSION_SQLALCHEMY'],
                config['SESSION_SQLALCHEMY_TABLE'],
                config['SESSION_KEY_PREFIX'], config['SESSION_USE_SIGNER'],
                config['SESSION_PERMANENT'])
        else:
            session_interface = NullSessionInterface()

        return session_interface

3.自定义session组件

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import uuid
import json
from flask.sessions import SessionInterface
from flask.sessions import SessionMixin
from itsdangerous import Signer, BadSignature, want_bytes


class MySession(dict, SessionMixin):
    def __init__(self, initial=None, sid=None):
        self.sid = sid
        self.initial = initial
        super(MySession, self).__init__(initial or ())

    def __setitem__(self, key, value):
        super(MySession, self).__setitem__(key, value)

    def __getitem__(self, item):
        return super(MySession, self).__getitem__(item)

    def __delitem__(self, key):
        super(MySession, self).__delitem__(key)


class MySessionInterface(SessionInterface):
    session_class = MySession
    container = {}

    def __init__(self):
        import redis
        self.redis = redis.Redis()

    def _generate_sid(self):
        return str(uuid.uuid4())

    def _get_signer(self, app):
        if not app.secret_key:
            return None
        return Signer(app.secret_key, salt='flask-session',
                      key_derivation='hmac')

    def open_session(self, app, request):
        """
        程序刚启动时执行，需要返回一个session对象
        """
        sid = request.cookies.get(app.session_cookie_name)
        if not sid:
            sid = self._generate_sid()
            return self.session_class(sid=sid)

        signer = self._get_signer(app)
        try:
            sid_as_bytes = signer.unsign(sid)
            sid = sid_as_bytes.decode()
        except BadSignature:
            sid = self._generate_sid()
            return self.session_class(sid=sid)

        # session保存在redis中
        # val = self.redis.get(sid)
        # session保存在内存中
        val = self.container.get(sid)

        if val is not None:
            try:
                data = json.loads(val)
                return self.session_class(data, sid=sid)
            except:
                return self.session_class(sid=sid)
        return self.session_class(sid=sid)

    def save_session(self, app, session, response):
        """
        程序结束前执行，可以保存session中所有的值
        如：
            保存到resit
            写入到用户cookie
        """
        domain = self.get_cookie_domain(app)
        path = self.get_cookie_path(app)
        httponly = self.get_cookie_httponly(app)
        secure = self.get_cookie_secure(app)
        expires = self.get_expiration_time(app, session)

        val = json.dumps(dict(session))

        # session保存在redis中
        # self.redis.setex(name=session.sid, value=val, time=app.permanent_session_lifetime)
        # session保存在内存中
        self.container.setdefault(session.sid, val)

        session_id = self._get_signer(app).sign(want_bytes(session.sid))

        response.set_cookie(app.session_cookie_name, session_id,
                            expires=expires, httponly=httponly,
                            domain=domain, path=path, secure=secure)

from flask import Flask
from flask import session
from my_session import MySessionInterface

app = Flask(__name__)

app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
app.session_interface = MySessionInterface()


@app.route('/login/', methods=['GET', "POST"])
def login():
    print(session)
    session['user1'] = 'alex'
    session['user2'] = 'alex'
    del session['user2']

    return "内容"


if __name__ == '__main__':
    app.run()