Improve `distributed.get_rank()` API docstring (#63296)

Summary:
See discussion in https://pytorch.slack.com/archives/CBHSWPNM7/p1628792389008600

Pull Request resolved: https://github.com/pytorch/pytorch/pull/63296

Reviewed By: cbalioglu

Differential Revision: D30332042

Pulled By: mrshenli

fbshipit-source-id: 3a642fda2e106fd35b67709ed2adb60e408854c2

diff --git a/torch/distributed/distributed_c10d.py b/torch/distributed/distributed_c10d.py
index fac096e..302114e 100644 (file)
--- a/torch/distributed/distributed_c10d.py
+++ b/torch/distributed/distributed_c10d.py
@@ -800,7 +800,8 @@ def destroy_process_group(group=None):
 
 def get_rank(group=None):
     """
-    Returns the rank of current process group
+    Returns the rank of the current process in the provided ``group`` or the
+    default group if none was provided.
 
     Rank is a unique identifier assigned to each process within a distributed
     process group. They are always consecutive integers ranging from 0 to