class Content(Base):
    __tablename__ = 'content'
id = sa.Column(sa.Integer, primary_key=True)
description = sa.Column(sa.UnicodeText, nullable=False, server_default='')

@declared_attr
def __table_args__(cls):
    return sa.Index('idx_content', sa.sql.func.to_tsvector('english', cls.
        description), postgresql_using='gin'),
SQLAlchemy with PostgresSQL and Full Text Search