flask-session

flask的介绍以及使用

"""
要用flask-session，得先安装 pip install flask-session

最初我们村session是存在cookie中的，session大字典就是cookie中的val

那我门想把session存放到redis中，就必须使用flask-session组件
"""

from flask import Flask, session
from flask_session import RedisSessionInterface
import redis
app = Flask(__name__)
conn = redis.Redis(host='127.0.0.1', port=6379, password='Admin123')
app.secret_key = 'alen is handsome'

#permanent=True,如果这个值为True,表示关闭浏览器，不失效，如果为Fasle,表示关闭浏览器，session就失效
#use_signer 默认是false，即可不需要秘钥，若改为true则需要配置秘钥
# 变成redis接口
app.session_interface = RedisSessionInterface(conn, key_prefix='alen', use_signer=True)


@app.route('/')
def hello_world():
    session['name'] = 'alen'
    return 'Hello World!'


@app.route('/index')
def index():
    print(session['name'])
    return 'ok'


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

flask-session的常规写法

from redis import Redis

from flask import Flask, session
from flask_session import Session

app = Flask(__name__)

app.config['SESSION-TYPE'] = 'redis'  # 配置你的数据库（可以支持其他类型数据库）
app.config['SESSION_TYPE'] = Redis(host='127.0.0.1', port='6379', password='Admin123')  # 把连接写在配置中

Session(app) # Session内部实现了接口连接


@app.route("/")
def index():
    session['name'] = "alen"
    return "ok"


@app.route("/index")
def index1():
    print(session['name'])
    return "ok"

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

flask-session的Session源码

  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