How to use the py4web.DAL function in py4web

def test_session_in_db(self):
        request.app_name = "myapp"
        db = DAL("sqlite:memory")
        session = Session(secret="a", expiration=10, storage=DBStore(db))
        request.cookies.clear()
        session.on_request()
        session["key"] = "value"
        session.on_success()
        cookie_name = session.local.session_cookie_name

        a, b = str(response._cookies)[len("Set-Cookie: ") :].split(";")[0].split("=", 1)
        request.cookies[a] = b
        request.cookies = response._cookies
        session.local.data.clear()

        session = Session(expiration=10, storage=DBStore(db))
        session.on_request()
        self.assertEqual(session.get("key"), "value")

import multiprocessing
import os
import time
import unittest
import uuid

import mechanize

from py4web import action, DAL, Field, Session, Cache
from py4web.core import bottle, request, error404

os.environ["PY4WEB_APPS_FOLDER"] = os.path.sep.join(
    os.path.normpath(__file__).split(os.path.sep)[:-2]
)

db = DAL("sqlite://storage_%s" % uuid.uuid4(), folder="/tmp/")
db.define_table("thing", Field("name"))
session = Session(secret="my secret")
cache = Cache()

action.app_name = "tests"


@action("index")
@cache.memoize(expiration=1)
@action.uses(db, session)
@action.requires(lambda: True)
def index():
    db.thing.insert(name="test")
    session["number"] = session.get("number", 0) + 1
    return "ok %s %s" % (session["number"], db(db.thing).count())

logger = logging.getLogger("py4web:" + settings.APP_NAME)
formatter = logging.Formatter(
    "%(asctime)s - %(levelname)s - %(filename)s:%(lineno)d - %(message)s"
)
for item in settings.LOGGERS:
    level, filename = item.split(":", 1)
    if filename in ("stdout", "stderr"):
        handler = logging.StreamHandler(getattr(sys, filename))
    else:
        handler = logging.FileHandler(filename)
    handler.setLevel(getattr(logging, level.upper(), "ERROR"))
    handler.setFormatter(formatter)
    logger.addHandler(handler)

# connect to db
db = DAL(settings.DB_URI, folder=settings.DB_FOLDER, pool_size=settings.DB_POOL_SIZE)

# define global objects that may or may not be used by th actions
cache = Cache(size=1000)
T = Translator(settings.T_FOLDER)

# pick the session type that suits you best
if settings.SESSION_TYPE == "cookies":
    session = Session(secret=settings.SESSION_SECRET_KEY)
elif settings.SESSION_TYPE == "redis":
    import redis

    host, port = settings.REDIS_SERVER.split(":")
    # for more options: https://github.com/andymccurdy/redis-py/blob/master/redis/client.py
    conn = redis.Redis(host=host, port=int(port))
    conn.set = lambda k, v, e, cs=conn.set, ct=conn.ttl: (cs(k, v), e and ct(e))
    session = Session(secret=settings.SESSION_SECRET_KEY, storage=conn)

import os
from py4web import action, request, DAL, Field, Session, Cache, user_in

# define session and cache objects
session = Session(secret="some secret")
cache = Cache(size=1000)

# define database and tables
db = DAL(
    "sqlite://storage.db", folder=os.path.join(os.path.dirname(__file__), "databases")
)
db.define_table("todo", Field("info"))
db.commit()

# example index page using session, template and vue.js
@action("index")  # the function below is exposed as a GET action
@action.uses("index.html")  # we use the template index.html to render it
@action.uses(session)  # action needs a session object (read/write cookies)
def index():
    session["counter"] = session.get("counter", 0) + 1
    session["user"] = {"id": 1}  # store a user in session
    return dict(session=session)


# example of GET/POST/DELETE RESTful APIs

import os
from py4web import DAL, Field
db = DAL('sqlite://test', folder=os.path.join(os.path.dirname(__file__), 'databases'))
db.define_table('thing', Field('name'))