Database migration tool for SQLAlchemy

Alembic is a database migrations tool written by the author of SQLAlchemy. A migrations tool offers the following functionality: • Can emit ALTER statements to a database in order to change the structure of tables and other constructs • Provides a system whereby "migration scripts" may be constructed; each script indicates a particular series of steps that can "upgrade" a target database to a new version, and optionally a series of steps that can "downgrade" similarly, doing the same steps in reverse. • Allows the scripts to execute in some sequential manner. Documentation and status of Alembic is at https://alembic.sqlalchemy.org/