diff --git a/python/obitools3/commands/head.pyx b/python/obitools3/commands/head.pyx
old mode 100644
new mode 100755
index 088e8e6..f40ab1f
--- a/python/obitools3/commands/head.pyx
+++ b/python/obitools3/commands/head.pyx
@@ -65,14 +65,14 @@ def run(config):
 
     # Save command config in View comments
     command_line = " ".join(sys.argv[1:])
-    comments = View.print_config(config, "head", command_line, input_dms_name=[i_dms.name], input_view_name=[i_view.name])
-
+    comments = View.get_config_dict(config, "head", command_line, input_dms_name=[i_dms.name], input_view_name=[i_view.name])
+    
     # Create output view with the line selection
     try:
         o_view = selection.materialize(output_view_name, comments=comments)
     except Exception, e:
         raise RollbackException("obi head error, rollbacking view: "+str(e), o_view)
-
+    
     # TODO DISCUSS if output URI to different DMS, copy view?
 
     # Save command config in DMS comments
diff --git a/python/obitools3/commands/tail.pyx b/python/obitools3/commands/tail.pyx
old mode 100644
new mode 100755
index 25af7af..ae32468
--- a/python/obitools3/commands/tail.pyx
+++ b/python/obitools3/commands/tail.pyx
@@ -65,7 +65,7 @@ def run(config):
 
     # Save command config in View comments
     command_line = " ".join(sys.argv[1:])
-    comments = View.print_config(config, "tail", command_line, input_dms_name=[i_dms.name], input_view_name=[i_view.name])
+    comments = View.get_config_dict(config, "tail", command_line, input_dms_name=[i_dms.name], input_view_name=[i_view.name])
 
     # Create output view with the line selection
     try:
diff --git a/python/obitools3/dms/view/view.pyx b/python/obitools3/dms/view/view.pyx
old mode 100644
new mode 100755
index 2b19bdc..c5c6ac5
--- a/python/obitools3/dms/view/view.pyx
+++ b/python/obitools3/dms/view/view.pyx
@@ -397,6 +397,15 @@ cdef class View(OBIWrapper) :
         # Convert to json string
         comments_json = json.dumps(config_dict)
         return str2bytes(comments_json)
+
+
+    @staticmethod
+    def get_config_dict(dict config, str command_name, str command_line, list input_str=None, list input_dms_name=None, list input_view_name=None):
+        config_dict = View._config_to_dict(config, command_name, command_line, \
+                                           input_str=input_str, input_dms_name=input_dms_name, input_view_name=input_view_name)
+        # Clean virtually empty values
+        config_dict = clean_empty_values_from_object(config_dict, exclude=[View_comments.KEEP_KEYS])
+        return config_dict
         
     
     @OBIWrapper.checkIsActive
@@ -611,7 +620,7 @@ cdef class View_comments(dict):   # Not thread safe
         comments_json = <bytes> view_p.infos.comments
         comments_json_str = bytes2str(comments_json)
         comments_dict = json.loads(comments_json_str)
-        str2bytes_object(comments_dict)
+        comments_dict = str2bytes_object(comments_dict)
         super(View_comments, self).update(comments_dict)
         
     def __getitem__(self, object key):