from sqlalchemy import create_engine

from sqlalchemy.orm import sessionmaker

engine = create_engine('sqlite:///:memory:', echo=True)

def createDatabase():

    Base.metadata.create_all(engine)

Session = sessionmaker(bind=engine)

class WithSession():

    def __init__(self,autocommit=False):

        self.autocommit=autocommit

    def __enter__(self):

        self.conn = engine.connect()

        self.session = Session(bind=self.conn)

        return self.session

    def __exit__(self,exc_type, exc_value, traceback):

        if exc_type is None:

            if self.autocommit:

                self.session.commit()

        else:

            self.session.rollback()

        self.session.close()

        self.conn.close()