models.py

from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

from tornado.options import options


def get_engine(memo=[]):
    if len(memo) == 0:
        memo.append(
            create_engine(options.database_url)
        )
    return memo[0]


def get_session(memo=[]):
    if len(memo) == 0:
        memo.append(
            sessionmaker(bind=get_engine())
        )
    return memo[0]()

Base = declarative_base()


class User(Base):
    __tablename__ = 'user'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    email = Column(String)