__init__.py

from sqlalchemy import engine_from_config
from .models import SipkdDBSession, SipkdBase

def main(global_config, **settings):
    url = 'sipkd.url' in settings and settings['sipkd.url'] and 'sipkd.' or 'sqlalchemy.'
    engine = engine_from_config(settings, url)
    SipkdDBSession.configure(bind=engine)
    SipkdBase.metadata.bind = engine