Example model

model.py

from sqlalchemy import Table, Column, Integer, String, ForeignKey
from sqlalchemy.orm import mapper
from database import metadata, db_session

class Team( object ):
    query = db_session.query_property()

    def __init__(self, name=None):
        self.name = name

    def __repr__(self):
        return '<User %r>' % (self.name)

class Package( object ) :
    query = db_session.query_property()

    def __init__ (self, name =None ):
        self.name = name
    
    def __repr__ (self) :
        return '<Package %r>' % (self.name)

teams = Table('teams', metadata,
    Column('id',Integer, primary_key=True),
    Column('name', String(50), unique=True)
)

packages = Table ('packages' , metadata, 
    Column( 'id',Integer,primary_key=True),
    Column( 'name',String(50), unique=True ) ,
    Column( 'teamid',Integer, ForeignKey('teams.id')),
)

mapper(Team, teams)
mapper(Package, packages )