[air] Add *path properties to Result and ResultGrid

python/ray/air/checkpoint.py

@@ -246,6 +246,37 @@ def _metadata(self, metadata: _CheckpointMetadata):
         for attr, value in metadata.checkpoint_state.items():
             setattr(self, attr, value)
 
+    @property
+    def path(self) -> Optional[str]:
+        """Return path to checkpoint, if available.
+
+        This will return a URI to cloud storage if this checkpoint is
+        persisted on cloud, or a local path if this checkpoint
+        is persisted on local disk and available on the current node.
+
+        In all other cases, this will return None.
+
+        Example:
+
+            >>> from ray.air import Checkpoint
+            >>> checkpoint = Checkpoint.from_uri("s3://some-bucket/some-location")
+            >>> assert checkpoint.path == "s3://some-bucket/some-location"
+            >>> checkpoint = Checkpoint.from_dict({"data": 1})
+            >>> assert checkpoint.path == None
+
+        Returns:
+            Checkpoint path if this checkpoint is reachable from the current node (e.g.
+            cloud storage or locally available directory).
+
+        """
+        if self._uri:
+            return self._uri
+
+        if self._local_path:
+            return self._local_path
+
+        return None
+
     @property
     def uri(self) -> Optional[str]:
         """Return checkpoint URI, if available.

python/ray/air/result.py

@@ -1,17 +1,19 @@
+import warnings
 from typing import TYPE_CHECKING
 from dataclasses import dataclass
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple
 
 from ray.air.checkpoint import Checkpoint
+from ray.util import log_once
 from ray.util.annotations import PublicAPI
 
 if TYPE_CHECKING:
     import pandas as pd
 
 
-@dataclass
 @PublicAPI(stability="beta")
+@dataclass
 class Result:
     """The final result of a ML training run or a Tune trial.
 
@@ -27,7 +29,6 @@ class Result:
         metrics: The final metrics as reported by an Trainable.
         checkpoint: The final checkpoint of the Trainable.
         error: The execution error of the Trainable run, if the trial finishes in error.
-        log_dir: Directory where the trial logs are saved.
         metrics_dataframe: The full result dataframe of the Trainable.
             The dataframe is indexed by iterations and contains reported
             metrics.
@@ -41,10 +42,27 @@ class Result:
     metrics: Optional[Dict[str, Any]]
     checkpoint: Optional[Checkpoint]
     error: Optional[Exception]
-    log_dir: Optional[Path]
-    metrics_dataframe: Optional["pd.DataFrame"]
-    best_checkpoints: Optional[List[Tuple[Checkpoint, Dict[str, Any]]]]
-    _items_to_repr = ["error", "metrics", "log_dir", "checkpoint"]
+    metrics_dataframe: Optional["pd.DataFrame"] = None
+    best_checkpoints: Optional[List[Tuple[Checkpoint, Dict[str, Any]]]] = None
+    _local_path: Optional[str] = None
+    _remote_path: Optional[str] = None
+    _items_to_repr = ["error", "metrics", "path", "checkpoint"]
+    # Deprecate: raise in 2.5, remove in 2.6
+    log_dir: Optional[Path] = None
+
+    def __post_init__(self):
+        if self.log_dir and log_once("result_log_dir_deprecated"):
+            warnings.warn(
+                "The `Result.log_dir` property is deprecated. "
+                "Use `local_path` instead."
+            )
+            self._local_path = str(self.log_dir)
+
+        # Duplicate for retrieval
+        self.log_dir = Path(self._local_path) if self._local_path else None
+        # Backwards compatibility: Make sure to cast Path to string
+        # Deprecate: Remove this line after 2.6
+        self._local_path = str(self._local_path) if self._local_path else None
 
     @property
     def config(self) -> Optional[Dict[str, Any]]:
@@ -53,11 +71,23 @@ def config(self) -> Optional[Dict[str, Any]]:
             return None
         return self.metrics.get("config", None)
 
+    @property
+    def path(self) -> str:
+        """Path pointing to the result directory on persistent storage.
+
+        This can point to a remote storage location (e.g. S3) or to a local
+        location (path on the head node).
+
+        For instance, if your remote storage path is ``s3://bucket/location``,
+        this will point to ``s3://bucket/location/experiment_name/trial_name``.
+        """
+        return self._remote_path or self._local_path
+
     def _repr(self, indent: int = 0) -> str:
         """Construct the representation with specified number of space indent."""
         from ray.tune.result import AUTO_RESULT_KEYS
 
-        shown_attributes = {k: self.__dict__[k] for k in self._items_to_repr}
+        shown_attributes = {k: getattr(self, k) for k in self._items_to_repr}
         if self.error:
             shown_attributes["error"] = type(self.error).__name__
         else:

python/ray/tune/analysis/experiment_analysis.py

@@ -115,6 +115,26 @@ def __init__(
 
         self._remote_storage_path = remote_storage_path
 
+    @property
+    def _local_path(self) -> str:
+        return str(self._local_experiment_path)
+
+    @property
+    def _remote_path(self) -> Optional[str]:
+        return self._parse_cloud_path(self._local_path)
+
+    @property
+    def experiment_path(self) -> str:
+        """Path pointing to the experiment directory on persistent storage.
+
+        This can point to a remote storage location (e.g. S3) or to a local
+        location (path on the head node).
+
+        For instance, if your remote storage path is ``s3://bucket/location``,
+        this will point to ``s3://bucket/location/experiment_name``.
+        """
+        return self._remote_path or self._local_path
+
     def _parse_cloud_path(self, local_path: str):
         """Convert local path into cloud storage path"""
         if not self._remote_storage_path:

python/ray/tune/experiment/trial.py

@@ -692,7 +692,6 @@ def remote_checkpoint_dir(self) -> Optional[str]:
 
     @property
     def remote_path(self) -> Optional[str]:
-        assert self.local_path, "Trial {}: logdir not initialized.".format(self)
         if not self._remote_experiment_path or not self.relative_logdir:
             return None
         uri = URI(self._remote_experiment_path)

python/ray/tune/result_grid.py

@@ -1,5 +1,4 @@
 import os
-from pathlib import Path
 from typing import Optional, Union
 
 import pandas as pd
@@ -73,6 +72,28 @@ def __init__(
             self._trial_to_result(trial) for trial in self._experiment_analysis.trials
         ]
 
+    @property
+    def _local_path(self) -> str:
+        """Return path pointing to the experiment directory on the local disk."""
+        return self._experiment_analysis._local_path
+
+    @property
+    def _remote_path(self) -> Optional[str]:
+        """Return path pointing to the experiment directory on remote storage."""
+        return self._experiment_analysis._remote_path
+
+    @property
+    def experiment_path(self) -> str:
+        """Path pointing to the experiment directory on persistent storage.
+
+        This can point to a remote storage location (e.g. S3) or to a local
+        location (path on the head node).
+
+        For instance, if your remote storage path is ``s3://bucket/location``,
+        this will point to ``s3://bucket/location/experiment_name``.
+        """
+        return self._remote_path or self._local_path
+
     def get_best_result(
         self,
         metric: Optional[str] = None,
@@ -232,7 +253,8 @@ def _trial_to_result(self, trial: Trial) -> Result:
             checkpoint=checkpoint,
             metrics=trial.last_result.copy(),
             error=self._populate_exception(trial),
-            log_dir=Path(trial.local_path) if trial.local_path else None,
+            _local_path=trial.local_path,
+            _remote_path=trial.remote_path,
             metrics_dataframe=self._experiment_analysis.trial_dataframes.get(
                 trial.local_path
             )

python/ray/tune/tests/test_result_grid.py

@@ -240,15 +240,15 @@ class MockExperimentAnalysis:
         Result(
             metrics={"loss": 1.0},
             checkpoint=Checkpoint(data_dict={"weight": 1.0}),
-            log_dir=Path("./log_1"),
+            _local_path=str(Path("./log_1")),
             error=None,
             metrics_dataframe=None,
             best_checkpoints=None,
         ),
         Result(
             metrics={"loss": 2.0},
             checkpoint=Checkpoint(data_dict={"weight": 2.0}),
-            log_dir=Path("./log_2"),
+            _local_path=str(Path("./log_2")),
             error=RuntimeError(),
             metrics_dataframe=None,
             best_checkpoints=None,
@@ -265,13 +265,13 @@ class MockExperimentAnalysis:
     expected_repr = """ResultGrid<[
   Result(
     metrics={'loss': 1.0},
-    log_dir=PosixPath('log_1'),
+    path='log_1',
     checkpoint=Checkpoint(data_dict={'weight': 1.0})
   ),
   Result(
     error='RuntimeError',
     metrics={'loss': 2.0},
-    log_dir=PosixPath('log_2'),
+    path='log_2',
     checkpoint=Checkpoint(data_dict={'weight': 2.0})
   )
 ]>"""
@@ -412,9 +412,25 @@ def train_func(config):
     for (checkpoint, _) in result_grid[0].best_checkpoints:
         assert checkpoint
         assert "moved_ray_results" in checkpoint._local_path
+        assert checkpoint._local_path.startswith(result_grid._local_path)
+
         checkpoint_data.append(checkpoint.to_dict()["it"])
     assert set(checkpoint_data) == {5, 6}
 
+    # Check local_path property
+    assert Path(result_grid._local_path).parent.name == "moved_ray_results"
+
+    # No upload path, so path should point to local_path
+    assert result_grid._local_path == result_grid.experiment_path
+
+    # Check Result objects
+    for result in result_grid:
+        assert result._local_path.startswith(result_grid._local_path)
+        assert result._local_path == result.path
+        assert result.path.startswith(result_grid.experiment_path)
+        assert result.checkpoint._local_path.startswith(result._local_path)
+        assert result.checkpoint.path.startswith(result.path)
+
 
 def test_result_grid_cloud_path(ray_start_2_cpus, tmpdir):
     # Test that checkpoints returned by ResultGrid point to URI
@@ -429,7 +445,7 @@ def trainable(config):
 
     tuner = tune.Tuner(
         trainable,
-        run_config=air.RunConfig(sync_config=sync_config, local_dir=local_dir),
+        run_config=air.RunConfig(sync_config=sync_config, local_dir=str(local_dir)),
         tune_config=tune.TuneConfig(
             metric="metric",
             mode="max",
@@ -444,6 +460,24 @@ def trainable(config):
         == results._experiment_analysis.best_checkpoint.get_internal_representation()
     )
 
+    # Check .remote_path property
+    assert results._remote_path.startswith("s3://bucket")
+    assert results.experiment_path.startswith("s3://bucket")
+    assert best_checkpoint.uri.startswith(results._remote_path)
+    assert best_checkpoint.path.startswith(results._remote_path)
+
+    # Upload path, so path should point to local_path
+    assert results._remote_path == results.experiment_path
+
+    # Check Result objects
+    for result in results:
+        assert result._local_path.startswith(results._local_path)
+        assert result._remote_path.startswith(results._remote_path)
+        assert result._remote_path == result.path
+        assert result.path.startswith(results.experiment_path)
+        assert result.checkpoint.uri.startswith(result._remote_path)
+        assert result.checkpoint.path.startswith(result.path)
+
 
 if __name__ == "__main__":
     import sys

python/ray/tune/tuner.py

@@ -106,17 +106,19 @@ def get_dataset():
         }
         tuner = Tuner(trainable=trainer, param_space=param_space,
             run_config=RunConfig(name="my_tune_run"))
-        analysis = tuner.fit()
+        results = tuner.fit()
 
     To retry a failed tune run, you can then do
 
     .. code-block:: python
 
-        tuner = Tuner.restore(experiment_checkpoint_dir)
+        tuner = Tuner.restore(results.experiment_path)
         tuner.fit()
 
-    ``experiment_checkpoint_dir`` can be easily located near the end of the
-    console output of your first failed run.
+    ``results.experiment_path`` can be retrieved from the
+    :ref:`ResultGrid object <tune-analysis-docs>`. It can
+    also be easily seen in the log output from your first run.
+
     """
 
     # One of the following is assigned.