improve type readability in errors (#469)

Signed-off-by: ijnek <kenjibrameld@gmail.com>
(cherry picked from commit 9c5f6a7)

Author: ijnek

launch_ros/launch_ros/parameter_descriptions.py

@@ -83,7 +83,7 @@ def value_type(self) -> AllowedTypesType:
     def __str__(self) -> Text:
         return (
             'launch_ros.description.ParameterValue'
-            f'(value={self.value}, value_type={self.value_type})'
+            f'(value={self.value}, value_type={self.value_type.__name__})'
         )
 
     def evaluate(self, context: LaunchContext) -> 'EvaluatedParameterValue':
@@ -148,7 +148,7 @@ def value_type(self) -> AllowedTypesType:
     def __str__(self) -> Text:
         return (
             'launch_ros.description.Parameter'
-            f'(name={self.name}, value={self.value}, value_type={self.value_type})'
+            f'(name={self.name}, value={self.value}, value_type={self.value_type.__name__})'
         )
 
     def evaluate(self, context: LaunchContext) -> Tuple[Text, 'EvaluatedParameterValue']:

launch_ros/launch_ros/utilities/evaluate_parameters.py

@@ -104,7 +104,7 @@ def check_sequence_type_is_allowed(sequence):
                         'If the parameter is meant to be a string, try wrapping it in '
                         'launch_ros.parameter_descriptions.ParameterValue'
                         '(value, value_type=str)'.format(
-                            type(yaml_evaluated_value),
+                            type(yaml_evaluated_value).__name__,
                             evaluated_name
                         )
                     )