database.py

from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.ext.declarative import declarative_base
import psycopg2 as dbapi2

POSTGRES = {
    'user': 'salil',
    'pw': 'salil',
    'db': 'salil',
    'host': 'localhost',
    'port': '5432',
}

SQLALCHEMY_DATABASE_URI = 'postgresql://%(user)s:\
%(pw)s@%(host)s:%(port)s/%(db)s' % POSTGRES

engine = create_engine(SQLALCHEMY_DATABASE_URI, convert_unicode=True)
db_session = scoped_session(sessionmaker(autocommit=False,
                                         autoflush=False,
                                         bind=engine))
Base = declarative_base()
Base.query = db_session.query_property()
cursor = db_session.connection().connection.cursor()

def init_db():
    # import all modules here that might define models so that
    # they will be registered properly on the metadata.  Otherwise
    # you will have to import them first before calling init_db()
    import models.models
    Base.metadata.create_all(bind=engine)