views.py 文件源码

def create_new_stacked_ensemble():
    path = functions.get_path_from_query_string(request)
    req_body = request.get_json()

    with functions.DBContextManager(path) as session:
        if request.method == 'GET':
                return jsonify(
                    list(map(lambda x: x.serialize, session.query(models.StackedEnsemble).all()))
                )

        if request.method == 'POST':
            base_learners = session.query(models.BaseLearner).\
                filter(models.BaseLearner.id.in_(req_body['base_learner_ids'])).all()
            if len(base_learners) != len(req_body['base_learner_ids']):
                raise exceptions.UserError('Not all base learners found')
            for learner in base_learners:
                if learner.job_status != 'finished':
                    raise exceptions.UserError('Not all base learners have finished')

            base_learner_origin = session.query(models.BaseLearnerOrigin).\
                filter_by(id=req_body['base_learner_origin_id']).first()
            if base_learner_origin is None:
                raise exceptions.UserError('Base learner origin {} not '
                                           'found'.format(req_body['base_learner_origin_id']), 404)

            # Retrieve full hyperparameters
            est = base_learner_origin.return_estimator()
            params = functions.import_object_from_string_code\
                (req_body['secondary_learner_hyperparameters_source'], 'params')
            est.set_params(**params)
            hyperparameters = functions.make_serializable(est.get_params())

            stacked_ensembles = session.query(models.StackedEnsemble).\
                filter_by(base_learner_origin_id=req_body['base_learner_origin_id'],
                          secondary_learner_hyperparameters=hyperparameters,
                          base_learner_ids=sorted([bl.id for bl in base_learners])).all()
            if stacked_ensembles:
                raise exceptions.UserError('Stacked ensemble exists')

            stacked_ensemble = models.StackedEnsemble(
                secondary_learner_hyperparameters=hyperparameters,
                base_learners=base_learners,
                base_learner_origin=base_learner_origin,
                job_status='queued'
            )

            session.add(stacked_ensemble)
            session.commit()

            with Connection(get_redis_connection()):
                rqtasks.evaluate_stacked_ensemble.delay(path, stacked_ensemble.id)

            return jsonify(stacked_ensemble.serialize)