Alt #1
    app_dict = {}
    for app in app_instances:
        if app_is_our_connector(app) and app_is_not_dashboard_connector(app):
            if app['aps']['type'] in app_dict:
                app_dict[app['aps']['type']] += app['aps']['id']
            else:
                app_dict[app['aps']['type']] = [app['aps']['id']]

Alt #2

    our_connectors = [
        (app['aps']['type'], app['aps']['id'])
        for app in app_instances
        if app_is_our_connector(app) and app_is_not_dashboard_connector(app)
    ]
    sorted_connectors = sorted(our_connectors, key=lambda c: c[0])
    connectors_versions = groupby(sorted_connectors, lambda c: c[0])
    app_dict = {
        aps_type: [inst_id for _, inst_id in ver_iter]
        for aps_type, ver_iter in connectors_versions
    }

Alt #3
    our_connectors = [
        (app['aps']['type'], app['aps']['id'])
        for app in app_instances
        if app_is_our_connector(app) and app_is_not_dashboard_connector(app)
    ]
    app_dict = {}
    for aps_type, instance_id in our_connectors:
        if aps_type in app_dict:
            app_dict[aps_type] += [instance_id]
        else:
            app_dict[aps_type] = [instance_id]