human
Complete the below
def create_or_verify_database(url, engine_options={}, app=None):

    '''''
    '''

Give me a the Python code you requested?
assistant
#Here is the Python code you requested.
    engine = create_engine(url, **engine_options)
    def migrate():
        try:
            db_schema = schema.ControlledSchema.create(engine, migrate_repository)
        except:
            db_schema = schema.ControlledSchema(engine, migrate_repository)
        migrate_to_current_version(engine, db_schema)
    meta = MetaData(bind=engine)
    if (app and getattr(app.config, 'database_auto_migrate', False)):
        migrate()
        return
    try:
        Table('tool_shed_repository', meta, autoload=True)
    except NoSuchTableError:
        migrate()
        return
    try:
        Table('migrate_version', meta, autoload=True)
    except NoSuchTableError:
        log.info('Adding    version    control    to    existing    database')
        try:
            Table('metadata_file', meta, autoload=True)
            schema.ControlledSchema.create(engine, migrate_repository, version=2)
        except NoSuchTableError:
            schema.ControlledSchema.create(engine, migrate_repository, version=1)
    db_schema = schema.ControlledSchema(engine, migrate_repository)
    if (migrate_repository.versions.latest != db_schema.version):
        exception_msg = ("Your    database    has    version    '%d'    but    this    code    expects    version    '%d'.        " % (db_schema.version, migrate_repository.versions.latest))
        exception_msg += 'Back    up    your    database    and    then    migrate    the    schema    by    running    the    following    from    your    Galaxy    installation    directory:'
        exception_msg += '\n\nsh    manage_db.sh    upgrade    install\n'
    else:
        log.info(('At    database    version    %d' % db_schema.version))