Use imperative mood in constructor docstrings. (ros2#103)

* Use imperative mood in constructor docstrings.

Fixes D401 in pycodestyle 5.0.0 and flake8.

Signed-off-by: Steven! Ragnarök <steven@nuclearsandwich.com>

* Use imperative mood in docstring.

Signed-off-by: Steven! Ragnarök <steven@nuclearsandwich.com>

* Use imperative mood in docstrings.

Signed-off-by: Steven! Ragnarök <steven@nuclearsandwich.com>

launch_ros/examples/lifecycle_pub_sub_launch.py

@@ -32,7 +32,7 @@
 
 
 def main(argv=sys.argv[1:]):
-    """Main."""
+    """Run lifecycle nodes via launch."""
     ld = launch.LaunchDescription()
 
     # Prepare the talker node.

launch_ros/examples/pub_sub_launch.py

@@ -28,7 +28,7 @@
 
 
 def main(argv=sys.argv[1:]):
-    """Main."""
+    """Run demo nodes via launch."""
     ld = LaunchDescription([
         launch_ros.actions.Node(
             package='demo_nodes_cpp', node_executable='talker', output='screen',

launch_ros/launch_ros/actions/push_ros_namespace.py

@@ -44,7 +44,7 @@ def __init__(
         namespace: SomeSubstitutionsType,
         **kwargs
     ) -> None:
-        """Constructor."""
+        """Create a PushRosNamespace action."""
         super().__init__(**kwargs)
         self.__namespace = normalize_to_list_of_substitutions(namespace)
 

launch_ros/launch_ros/default_launch_description.py

@@ -29,7 +29,7 @@ class ROSSpecificLaunchStartup(launch.actions.OpaqueFunction):
     """Does ROS specific launch startup."""
 
     def __init__(self, rclpy_context=None):
-        """Constructor."""
+        """Create a ROSSpecificLaunchStartup opaque function."""
         super().__init__(function=self._function)
         self.__shutting_down = False
         self.__rclpy_context = rclpy_context

launch_ros/launch_ros/event_handlers/on_state_transition.py

@@ -42,7 +42,7 @@ def __init__(
         **kwargs
     ) -> None:
         """
-        Constructor.
+        Create an OnStateTransition event handler.
 
         There are several matching options, each of which is compared with the
         event and must match it to have the handler handle the event.

launch_ros/launch_ros/events/lifecycle/change_state.py

@@ -71,7 +71,7 @@ def __init__(
         transition_id: int
     ) -> None:
         """
-        Constructor.
+        Create a ChangeState event.
 
         :param: lifecycle_node_matcher is a callable which returns True if the
             given lifecycle node should be affected by this event.

launch_ros/launch_ros/events/lifecycle/state_transition.py

@@ -37,7 +37,7 @@ def __init__(
         msg: lifecycle_msgs.msg.TransitionEvent
     ) -> None:
         """
-        Constructor.
+        Create a StateTransition event.
 
         :param: action the instance of class::`LifecycleNode` that generated this event
         :param: msg the instance of the ROS message TransitionEvent that generated this event

launch_ros/launch_ros/substitutions/executable_in_package.py

@@ -46,7 +46,7 @@ class ExecutableInPackage(FindPackagePrefix):
     """
 
     def __init__(self, executable: SomeSubstitutionsType, package: SomeSubstitutionsType) -> None:
-        """Constructor."""
+        """Create an ExecutableInPackage substitution."""
         super().__init__(package)
         self.__executable = normalize_to_list_of_substitutions(executable)
 

launch_ros/launch_ros/substitutions/find_package.py

@@ -40,7 +40,7 @@ def __init__(
         self,
         package: SomeSubstitutionsType,
     ) -> None:
-        """Constructor."""
+        """Create a FindPackage substitution."""
         super().__init__()
         self.__package = normalize_to_list_of_substitutions(package)
 

ros2launch/ros2launch/api/api.py

@@ -34,7 +34,7 @@ class MultipleLaunchFilesError(Exception):
     """Exception raised when multiple candidate launch files are found in a package."""
 
     def __init__(self, msg, paths):
-        """Constructor."""
+        """Create a MultipleLaunchFilesError."""
         super().__init__(msg)
         self.paths = paths
 
@@ -168,7 +168,7 @@ class LaunchFileNameCompleter:
     """Callable returning a list of launch file names within a package's share directory."""
 
     def __init__(self, *, package_name_key=None):
-        """Constructor."""
+        """Create LaunchFileNameCompleter."""
         self.package_name_key = 'package_name' if package_name_key is None else package_name_key
 
     def __call__(self, prefix, parsed_args, **kwargs):