How do I create as assoc record with SQLAlchemy in Pylons?

I've got a User model and a Ledger model with a many-to-many relationship. SQLAlchemy has created my database tables correctly, so I'm pretty sure it's got the right mappings. I can create a new record in each table, but I can't figure out how to associate them. How do I do it?

My table definitions:

user_table = sa.Table('user', meta.metadata,
    sa.Column('id', types.Integer,
        sa.Sequence('user_seq_id', optional=True), primary_key=True),
    sa.Column('username', types.Unicode(255), nullable=False, unique=True),
    sa.Column('password', types.Unicode(255), nullable=False),
    sa.Column('salt', types.Unicode(255), nullable=False)
    )
userledger_table = sa.Table('userledger', meta.metadata,
    sa.Column('id', types.Integer,
        sa.Sequence('user_seq_id', optional=True), primary_key=True),
    sa.Column('user_id', types.Integer(), sa.ForeignKey('user.id')),
    sa.Column('ledger_id', types.Integer(), sa.ForeignKey('ledger.id')),
    )
ledger_table = sa.Table('ledger', meta.metadata,
    sa.Column('id', types.Integer,
        sa.Sequence('ledger_seq_id', optional=True), primary_key=True),
    sa.Column('name', types.Unicode(255), nullable=False),
    )

Mappings:

orm.mapper(User, user_table);
orm.mapper(Ledger, ledger_table, properties={
    'users':orm.relation(User, seconda开发者_运维技巧ry=userledger_table)
    })

I found my answer in this tutorial.

ledger = model.Ledger()
ledger.name = name
ledger.users.append(user)
meta.Session.add(ledger)
meta.Session.commit()