mimir_blogpost_requestlocals.py

from sqlalchemy import engine_from_config
from sqlalchemy.orm import sessionmaker
from zope.sqlalchemy import register
import transaction
# https://github.com/inklesspen/mimir/blob/fee47910e149094a339a26297324d61568dbadf3/mimir/models/__init__.py#L259-L278

def create_session(request):
    sessionmaker = request.registry['db_sessionmaker']
    session = sessionmaker()
    register(session, transaction_manager=request.tm)
    return session


def pyramid_tm_hook(request=None):
    return transaction.TransactionManager()


def includeme(config):
    config.add_settings({'tm.manager_hook': pyramid_tm_hook})
    settings = config.get_settings()
    config.include('pyramid_tm')
    engine = engine_from_config(settings, 'sqlalchemy.')
    maker = sessionmaker()
    maker.configure(bind=engine)
    config.registry['db_sessionmaker'] = maker
    config.add_request_method(create_session, 'db_session', reify=True)