Tweaks to saved_model_cli to support empty tag-sets.

Handling of tag sets via string join and split leads to convert an empty list
into a list with empty string. Instead of fixing the get_meta_graph_def to receive
a list of tags instead of a string and move the issue to the caller of it,
get_meta_graph now ignores tags that are empty.

Additionally change print of the tag sets so use '%r' so that it is clear there is
a tag set (i.e. '') instead of printing an empty line.

PiperOrigin-RevId: 286375150
Change-Id: I8b6b17c8c1a30d76bbebfbfffdf064e367e526f9

tensorflow/python/tools/saved_model_cli.py

@@ -62,7 +62,7 @@ def _show_tag_sets(saved_model_dir):
   tag_sets = saved_model_utils.get_saved_model_tag_sets(saved_model_dir)
   print('The given SavedModel contains the following tag-sets:')
   for tag_set in sorted(tag_sets):
-    print(', '.join(sorted(tag_set)))
+    print('%r' % ', '.join(sorted(tag_set)))
 
 
 def _show_signature_def_map_keys(saved_model_dir, tag_set):

tensorflow/python/tools/saved_model_cli_test.py

@@ -244,7 +244,7 @@ Defined Functions:
     with captured_output() as (out, err):
       saved_model_cli.show(args)
     output = out.getvalue().strip()
-    exp_out = 'The given SavedModel contains the following tag-sets:\nserve'
+    exp_out = 'The given SavedModel contains the following tag-sets:\n\'serve\''
     self.assertMultiLineEqual(output, exp_out)
     self.assertEqual(err.getvalue().strip(), '')
 

tensorflow/python/tools/saved_model_utils.py

@@ -83,7 +83,8 @@ def get_saved_model_tag_sets(saved_model_dir):
     saved_model_dir: Directory containing the SavedModel.
 
   Returns:
-    String representation of all tag-sets in the SavedModel.
+    List of all tag-sets in the SavedModel, where a tag-set is represented as a
+    list of strings.
   """
   saved_model = read_saved_model(saved_model_dir)
   all_tags = []
@@ -98,10 +99,11 @@ def get_meta_graph_def(saved_model_dir, tag_set):
   Returns the MetaGraphDef for the given tag-set and SavedModel directory.
 
   Args:
-    saved_model_dir: Directory containing the SavedModel to inspect or execute.
+    saved_model_dir: Directory containing the SavedModel to inspect.
     tag_set: Group of tag(s) of the MetaGraphDef to load, in string format,
-        separated by ','. For tag-set contains multiple tags, all tags must be
-        passed in.
+        separated by ','. The empty string tag is ignored so that passing ''
+        means the empty tag set. For tag-set contains multiple tags, all tags
+        must be passed in.
 
   Raises:
     RuntimeError: An error when the given tag-set does not exist in the
@@ -111,10 +113,11 @@ def get_meta_graph_def(saved_model_dir, tag_set):
     A MetaGraphDef corresponding to the tag-set.
   """
   saved_model = read_saved_model(saved_model_dir)
-  set_of_tags = set(tag_set.split(','))
+  # Note: Discard empty tags so that "" can mean the empty tag set.
+  set_of_tags = set([tag for tag in tag_set.split(",") if tag])
   for meta_graph_def in saved_model.meta_graphs:
     if set(meta_graph_def.meta_info_def.tags) == set_of_tags:
       return meta_graph_def
 
-  raise RuntimeError('MetaGraphDef associated with tag-set ' + tag_set +
-                     ' could not be found in SavedModel')
+  raise RuntimeError("MetaGraphDef associated with tag-set %r could not be"
+                     " found in SavedModel" % tag_set)