def migrate_app(migrations, target_name=None, merge=False, fake=False, db_dry_run=False, yes=False, verbosity=0, load_initial_data=False, skip=False, database=DEFAULT_DB_ALIAS, delete_ghosts=False, ignore_ghosts=False, interactive=False):
    app_label = migrations.app_label()

    verbosity = int(verbosity)
    # Fire off the pre-migrate signal
    pre_migrate.send(None, app=app_label, verbosity=verbosity, interactive=verbosity, db=database)
    
    # If there aren't any, quit quizically
    if not migrations:
        print("? You have no migrations for the '%s' app. You might want some." % app_label)
        return
    
    # Load the entire dependency graph
    Migrations.calculate_dependencies()
    
    # Check there's no strange ones in the database
    applied_all = MigrationHistory.objects.filter(applied__isnull=False).order_by('applied').using(database)
    applied = applied_all.filter(app_name=app_label).using(database)
    south.db.db = south.db.dbs[database]
    Migrations.invalidate_all_modules()
    
    south.db.db.debug = (verbosity > 1)

    if target_name == 'current-1':
        if applied.count() > 1:
            previous_migration = applied[applied.count() - 2]
            if verbosity:
                print('previous_migration: %s (applied: %s)' % (previous_migration.migration, previous_migration.applied))
            target_name = previous_migration.migration
        else:
            if verbosity:
                print('previous_migration: zero')
            target_name = 'zero'
    elif target_name == 'current+1':
        try:
            first_unapplied_migration = get_unapplied_migrations(migrations, applied).next()
            target_name = first_unapplied_migration.name()
        except __HOLE__:
            target_name = None
    
    applied_all = check_migration_histories(applied_all, delete_ghosts, ignore_ghosts)
    
    # Guess the target_name
    target = migrations.guess_migration(target_name)
    if verbosity:
        if target_name not in ('zero', None) and target.name() != target_name:
            print(" - Soft matched migration %s to %s." % (target_name,
                                                           target.name()))
        print("Running migrations for %s:" % app_label)
    
    # Get the forwards and reverse dependencies for this target
    direction, problems, workplan = get_direction(target, applied_all, migrations,
                                                  verbosity, interactive)
    if problems and not (merge or skip):
        raise exceptions.InconsistentMigrationHistory(problems)
    
    # Perform the migration
    migrator = get_migrator(direction, db_dry_run, fake, load_initial_data)
    if migrator:
        migrator.print_title(target)
        success = migrator.migrate_many(target, workplan, database)
        # Finally, fire off the post-migrate signal
        if success:
            post_migrate.send(None, app=app_label, verbosity=verbosity, interactive=verbosity, db=database)
    else:
        if verbosity:
            # Say there's nothing.
            print('- Nothing to migrate.')
        # If we have initial data enabled, and we're at the most recent
        # migration, do initial data.
        # Note: We use a fake Forwards() migrator here. It's never used really.
        if load_initial_data:
            migrator = LoadInitialDataMigrator(migrator=Forwards(verbosity=verbosity))
            migrator.load_initial_data(target, db=database)
        # Send signal.
        post_migrate.send(None, app=app_label, verbosity=verbosity, interactive=verbosity, db=database)
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/South-1.0.2/south/migration/__init__.py/migrate_app