models.py

from sqlalchemy import Table, Column, Integer, String, ForeignKey
from sqlalchemy.orm import mapper
from database import metadata, db_session , Base
from sqlalchemy.ext.declarative import declarative_base


class Team( Base ):
    __tablename__='teams'
    id = Column (Integer, primary_key = True)
    name = Column(String(50))
    addresses = relationship ( "Package",backref="team",primaryjoin = Team.id == Package.teamid )
  

class Package(Base):
    __tablename__='packages'

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