Base = declarative_base()
class User(Base):
  __tablename__ = 'users1'

  id = Column(Integer, primary_key=True)
  name = Column(String)
  fullname = Column(String)
  password = Column(String)

  def __repr__(self):
    return "<User(name='%s, username = '%s', password='%s')>" %(self.name, self.fullname, self.password)



engine = create_engine('sqlite:///test2.db', echo=True)
Base.metadata.create_all(engine)

Session = sessionmaker(bind=engine)
Session = sessionmaker()
Session.configure(bind=engine)
session = Session()

class Address(Base):
  __tablename__ = 'addresses'
  id = Column(Integer, primary_key=True)
  email_address = Column(String, nullable=False)
  user_id = Column(Integer, ForeignKey('users.id'))
  user = relationship("User", back_populates="addresses")
  def __repr__(self):
    return "<Address(email_address='%s')>" % self.email_address

User.addresses = relationship("Address", order_by=Address.id, back_populates="user")

sqlalchemy.exc.NoForeignKeysError: Could not determine join condition between parent/child tables on relationship User.addresses - there are no foreign keys linking these tables.  Ensure that referencing columns are associated with a ForeignKey or ForeignKeyConstraint, or specify a 'primaryjoin' expression.