Change timeout from milliseconds to seconds in ray.wait. (#3706)

* Change timeout from milliseconds to seconds in ray.wait.

* Suppress warning.

* Suppress warning.

* Add prominent warning in API documentation.

python/ray/experimental/api.py

@@ -52,8 +52,8 @@ def wait(object_ids, num_returns=1, timeout=None, worker=None):
             List like of object IDs for objects that may or may not be ready.
             Note that these IDs must be unique.
         num_returns (int): The number of object IDs that should be returned.
-        timeout (int): The maximum amount of time in milliseconds to wait
-            before returning.
+        timeout (float): The maximum amount of time in seconds to wait before
+            returning.
 
     Returns:
         A list of object IDs that are ready and a list of the remaining object
@@ -61,6 +61,11 @@ def wait(object_ids, num_returns=1, timeout=None, worker=None):
     """
     worker = ray.worker.global_worker if worker is None else worker
     if isinstance(object_ids, (tuple, np.ndarray)):
-        return ray.wait(list(object_ids), num_returns, timeout, worker)
+        return ray.wait(
+            list(object_ids),
+            num_returns=num_returns,
+            timeout=timeout,
+            worker=worker)
 
-    return ray.wait(object_ids, num_returns, timeout, worker)
+    return ray.wait(
+        object_ids, num_returns=num_returns, timeout=timeout, worker=worker)