[tune] implement shim instantiation (#10456)

* Create ray.tune.suggest.create.create_scheduler

* Update __init__.py

* Resolve conflict in __init__.py

* Create ray.tune.schedulers.create.create_scheduler

* Update __init__.py

* Move create_scheduler to tune.schedulers.__init__

* Move create_searcher to tune.suggest.__init__

* Delete tune.suggest.create

* Delete tune.schedulers.create

* Update imports for shim functions in tune.__init__

* Remove shim from tune.suggest.__init__.__all__

* Remove shim from tune.schedulers.__init__.__all__

* Add ShimCreationTest

* Move ShimCreationTest to test_api

* Delete test_shim.py

* Add docstring for ray.tune.create_scheduler

* Add docstring to ray.tune.create_searcher

* Fix typo in ray.tune.create_scheduler docstring

* Fix lint errors in tune.schedulers.__init__

* Fix lint errors in tune.suggest.__init__

* Fix lint errors in tune.suggest.__init__

* Fix lint errors in tune.schedulers.__init__

* Fix imports in test_api

* Fix lint errors in test_api

* Fix kwargs in create_searcher

* Fix kwargs in create_scheduler

* Merge branch 'master' into shim-instantiation

* Update use-case in docs in tune.create_scheduler

* Update use-case in docs in tune.create_searcher

* Remove duplicate pytest run from test_api

* Add check to create_searcher


Co-authored-by: Richard Liaw <rliaw@berkeley.edu>

* Add check to create_scheduler

* lint

* Compare types of instances in test_api

Co-authored-by: Richard Liaw <rliaw@berkeley.edu>

* Add tune.create_searcher to docs

* Fix doc build

* Fix tests

* Add tune.create_scheduler to docs

* Fix tests

* Fix lint errors

* Update Ax search for master

* Fix metric kwarg for Ax in test_api

* Fix doc build

* Fix HyperOptSearch import in test_api

* Fix HyperOptSearch import in create_searcher

Co-authored-by: Richard Liaw <rliaw@berkeley.edu>

python/ray/tune/tests/test_api.py

@@ -14,7 +14,8 @@ from ray import tune
 from ray.tune import (DurableTrainable, Trainable, TuneError, Stopper,
                       EarlyStopping)
 from ray.tune import register_env, register_trainable, run_experiments
-from ray.tune.schedulers import TrialScheduler, FIFOScheduler
+from ray.tune.schedulers import (TrialScheduler, FIFOScheduler,
+                                 AsyncHyperBandScheduler)
 from ray.tune.trial import Trial
 from ray.tune.result import (TIMESTEPS_TOTAL, DONE, HOSTNAME, NODE_IP, PID,
                              EPISODES_TOTAL, TRAINING_ITERATION,
@@ -24,6 +25,8 @@ from ray.tune.logger import Logger
 from ray.tune.experiment import Experiment
 from ray.tune.resources import Resources
 from ray.tune.suggest import grid_search
+from ray.tune.suggest.hyperopt import HyperOptSearch
+from ray.tune.suggest.ax import AxSearch
 from ray.tune.suggest._mock import _MockSuggestionAlgorithm
 from ray.tune.utils import (flatten_dict, get_pinned_object,
                             pin_in_object_store)
@@ -1105,6 +1108,30 @@ class TrainableFunctionApiTest(unittest.TestCase):
             self.assertIn("LOG_STDERR", content)
 
 
+class ShimCreationTest(unittest.TestCase):
+    def testCreateScheduler(self):
+        kwargs = {"metric": "metric_foo", "mode": "min"}
+
+        scheduler = "async_hyperband"
+        shim_scheduler = tune.create_scheduler(scheduler, **kwargs)
+        real_scheduler = AsyncHyperBandScheduler(**kwargs)
+        assert type(shim_scheduler) is type(real_scheduler)
+
+    def testCreateSearcher(self):
+        kwargs = {"metric": "metric_foo", "mode": "min"}
+
+        searcher_ax = "ax"
+        shim_searcher_ax = tune.create_searcher(searcher_ax, **kwargs)
+        real_searcher_ax = AxSearch(space=[], **kwargs)
+        assert type(shim_searcher_ax) is type(real_searcher_ax)
+
+        searcher_hyperopt = "hyperopt"
+        shim_searcher_hyperopt = tune.create_searcher(searcher_hyperopt,
+                                                      **kwargs)
+        real_searcher_hyperopt = HyperOptSearch({}, **kwargs)
+        assert type(shim_searcher_hyperopt) is type(real_searcher_hyperopt)
+
+
 if __name__ == "__main__":
     import pytest
     import sys