[tune] Support "None" for upload_dir

python/ray/tune/experiment.py

@@ -85,7 +85,7 @@ class Experiment(object):
                  repeat=1,
                  num_samples=1,
                  local_dir=None,
-                 upload_dir="",
+                 upload_dir=None,
                  checkpoint_freq=0,
                  checkpoint_at_end=False,
                  max_failures=3,
@@ -97,7 +97,7 @@ class Experiment(object):
             "trial_resources": trial_resources,
             "num_samples": num_samples,
             "local_dir": local_dir or DEFAULT_RESULTS_DIR,
-            "upload_dir": upload_dir,
+            "upload_dir": upload_dir or "",  # argparse converts None to "null"
             "checkpoint_freq": checkpoint_freq,
             "checkpoint_at_end": checkpoint_at_end,
             "max_failures": max_failures,

python/ray/tune/test/trial_runner_test.py

@@ -185,6 +185,21 @@ class TrainableFunctionApiTest(unittest.TestCase):
             }
         })
 
+    def testUploadDirNone(self):
+        def train(config, reporter):
+            reporter(timesteps_total=1)
+
+        [trial] = run_experiments({
+            "foo": {
+                "run": train,
+                "upload_dir": None,
+                "config": {
+                    "a": "b"
+                },
+            }
+        })
+        self.assertFalse(trial.upload_dir)
+
     def testLogdirStartingWithTilde(self):
         local_dir = '~/ray_results/local_dir'