REPL setup for sqlalchemy

from sqlalchemy import MetaData, create_engine, orm
from sqlalchemy.sql import select

engine = create_engine('postgresql+psycopg2://username:password@localhost:5432/dbname')
Session = orm.sessionmaker(bind=engine)
session = Session()
metadata = MetaData(bind=engine)
metadata.reflect()
table_1 = metadata.tables['table_1']
table_1_column_1 = table_1.columns['column_1']
labelled_column = table_1_column_1.label('my test column')

query = select([labelled_column]).select_from(table_1).order_by(labelled_column)

query = session.query(table_1).select(table_1_column_1)
str(query) # shows the SQL