Skip None Result (#646)

Signed-off-by: jaywang <iwmq@qq.com>
(cherry picked from commit a9def45)

# Conflicts:
#	ros2param/ros2param/verb/list.py

ros2param/ros2param/verb/list.py

@@ -104,3 +104,29 @@ def main(self, *, args):  # noqa: D102
                     print(
                         'Exception while calling service of node '
                         f"'{node_name.full_name}': {e}", file=sys.stderr)
+<<<<<<< HEAD
+=======
+                    continue
+                response = future.result()
+                sorted_names = sorted(response.result.names)
+                if regex_filter is not None:
+                    sorted_names = [name for name in sorted_names if regex_filter.match(name)]
+                if not args.node_name and sorted_names:
+                    print(f'{node_name.full_name}:')
+                # get descriptors for the node if needs to print parameter type
+                name_to_type_map = {}
+                if args.param_type is True:
+                    resp = call_describe_parameters(
+                        node=node, node_name=node_name.full_name,
+                        parameter_names=sorted_names)
+                    for descriptor in resp.descriptors:
+                        name_to_type_map[descriptor.name] = get_parameter_type_string(
+                            descriptor.type)
+
+                for name in sorted_names:
+                    if args.param_type is True:
+                        param_type_str = name_to_type_map[name]
+                        print(f'  {name} (type: {param_type_str})')
+                    else:
+                        print(f'  {name}')
+>>>>>>> a9def45 (Skip None Result (#646))