Included comments in the python section of the tutorial.

follow_joint_trajectory.md

@@ -17,15 +17,15 @@ roslaunch stretch_core stretch_driver.launch
 In a new terminal type the following commands.
 
 ```bash
-cd catkin_ws/src/stretch_ros_turotials/src/
-python3 stow_command.py
+cd catkin_ws/src/stretch_ros_tutorials/src/
+python stow_command.py
 ```
 
 This will send a FollowJointTrajectory command to stow Stretch's arm.
 ### The Code
 
 ```python
-#!/usr/bin/env python3
+#!/usr/bin/env python
 
 import rospy
 from control_msgs.msg import FollowJointTrajectoryGoal
@@ -34,38 +34,48 @@ import hello_helpers.hello_misc as hm
 import time
 
 class StowCommand(hm.HelloNode):
+  '''
+  A class that sends a joint trajectory goal to stow the Stretch's arm.
+  '''
+  def __init__(self):
+    hm.HelloNode.__init__(self)
+
+  def issue_stow_command(self):
+    '''
+    Function that makes an action call and sends stow postion goal.
+    :param self: The self reference.
+    '''
+    stow_point = JointTrajectoryPoint()
+    stow_point.time_from_start = rospy.Duration(0.000)
+    stow_point.positions = [0.2, 0.0, 3.4]
 
-    def __init__(self):
-        hm.HelloNode.__init__(self)
-
-    def issue_stow_command(self):
-        stow_point = JointTrajectoryPoint()
-        stow_point.time_from_start = rospy.Duration(0.000)
-        stow_point.positions = [0.2, 0.0, 3.4]
-
-        trajectory_goal = FollowJointTrajectoryGoal()
-        trajectory_goal.trajectory.joint_names = ['joint_lift', 'wrist_extension', 'joint_wrist_yaw']
-        trajectory_goal.trajectory.points = [stow_point]
-        trajectory_goal.trajectory.header.stamp = rospy.Time(0.0)
-        trajectory_goal.trajectory.header.frame_id = 'base_link'
+    trajectory_goal = FollowJointTrajectoryGoal()
+    trajectory_goal.trajectory.joint_names = ['joint_lift', 'wrist_extension', 'joint_wrist_yaw']
+    trajectory_goal.trajectory.points = [stow_point]
+    trajectory_goal.trajectory.header.stamp = rospy.Time(0.0)
+    trajectory_goal.trajectory.header.frame_id = 'base_link'
 
-        self.trajectory_client.send_goal(trajectory_goal)
-        rospy.loginfo('Sent stow goal = {0}'.format(trajectory_goal))
-        self.trajectory_client.wait_for_result()
+    self.trajectory_client.send_goal(trajectory_goal)
+    rospy.loginfo('Sent stow goal = {0}'.format(trajectory_goal))
+    self.trajectory_client.wait_for_result()
 
-    def main(self):
-        hm.HelloNode.main(self, 'stow_command', 'stow_command', wait_for_first_pointcloud=False)
-        rospy.loginfo('stowing...')
-        self.issue_stow_command()
-        time.sleep(2)
+  def main(self):
+    '''
+    Function that initiates stow_command function.
+    :param self: The self reference.
+    '''
+    hm.HelloNode.main(self, 'stow_command', 'stow_command', wait_for_first_pointcloud=False)
+    rospy.loginfo('stowing...')
+    self.issue_stow_command()
+    time.sleep(2)
 
 
 if __name__ == '__main__':
-    try:
-        node = StowCommand()
-        node.main()
-    except KeyboardInterrupt:
-        rospy.loginfo('interrupt received, so shutting down')
+  try:
+    node = StowCommand()
+    node.main()
+  except KeyboardInterrupt:
+    rospy.loginfo('interrupt received, so shutting down')
 ```
 
 ### The Code Explained
@@ -73,7 +83,7 @@ if __name__ == '__main__':
 Now let's break the code down.
 
 ```python
-#!/usr/bin/env python3
+#!/usr/bin/env python
 ```
 Every Python ROS [Node](http://wiki.ros.org/Nodes) will have this declaration at the top. The first line makes sure your script is executed as a Python script.
 
@@ -156,15 +166,15 @@ roslaunch stretch_core stretch_driver.launch
 In a new terminal type the following commands.
 
 ```bash
-cd catkin_ws/src/stretch_ros_turotials/src/
-python3 multipoint_command.py
+cd catkin_ws/src/stretch_ros_tutorials/src/
+python multipoint_command.py
 ```
 
 This will send a list of JointTrajectoryPoint's to move Stretch's arm.
 
 ### The Code
 ```python
-#!/usr/bin/env python3
+#!/usr/bin/env python
 
 import rospy
 import time
@@ -173,54 +183,64 @@ from trajectory_msgs.msg import JointTrajectoryPoint
 import hello_helpers.hello_misc as hm
 
 class MultiPointCommand(hm.HelloNode):
+  """
+  A class that sends multiple joint trajectory goals to the stretch robot.
+  """
+  def __init__(self):
+    hm.HelloNode.__init__(self)
 
-    def __init__(self):
-        hm.HelloNode.__init__(self)
-
-    def issue_multipoint_command(self):
-      point0 = JointTrajectoryPoint()
-      point0.positions = [0.2, 0.0, 3.4]
-      point0.velocities = [0.2, 0.2, 2.5]
-      point0.accelerations = [1.0, 1.0, 3.5]
+  def issue_multipoint_command(self):
+    """
+    Function that makes an action call and sends multiple joint trajectory goals.
+    :param self: The self reference.
+    """
+    point0 = JointTrajectoryPoint()
+    point0.positions = [0.2, 0.0, 3.4]
+    point0.velocities = [0.2, 0.2, 2.5]
+    point0.accelerations = [1.0, 1.0, 3.5]
 
-      point1 = JointTrajectoryPoint()
-      point1.positions = [0.3, 0.1, 2.0]
+    point1 = JointTrajectoryPoint()
+    point1.positions = [0.3, 0.1, 2.0]
 
-      point2 = JointTrajectoryPoint()
-      point2.positions = [0.5, 0.2, -1.0]
+    point2 = JointTrajectoryPoint()
+    point2.positions = [0.5, 0.2, -1.0]
 
-      point3 = JointTrajectoryPoint()
-      point3.positions = [0.6, 0.3, 0.0]
+    point3 = JointTrajectoryPoint()
+    point3.positions = [0.6, 0.3, 0.0]
 
-      point4 = JointTrajectoryPoint()
-      point4.positions = [0.8, 0.2, 1.0]
+    point4 = JointTrajectoryPoint()
+    point4.positions = [0.8, 0.2, 1.0]
 
-      point5 = JointTrajectoryPoint()
-      point5.positions = [0.5, 0.1, 0.0]
+    point5 = JointTrajectoryPoint()
+    point5.positions = [0.5, 0.1, 0.0]
 
-      trajectory_goal = FollowJointTrajectoryGoal()
-      trajectory_goal.trajectory.joint_names = ['joint_lift', 'wrist_extension', 'joint_wrist_yaw']
-      trajectory_goal.trajectory.points = [point0, point1, point2, point3, point4, point5]
-      trajectory_goal.trajectory.header.stamp = rospy.Time(0.0)
-      trajectory_goal.trajectory.header.frame_id = 'base_link'
-
-      self.trajectory_client.send_goal(trajectory_goal)
-      rospy.loginfo('Sent stow goal = {0}'.format(trajectory_goal))
-      self.trajectory_client.wait_for_result()
+    trajectory_goal = FollowJointTrajectoryGoal()
+    trajectory_goal.trajectory.joint_names = ['joint_lift', 'wrist_extension', 'joint_wrist_yaw']
+    trajectory_goal.trajectory.points = [point0, point1, point2, point3, point4, point5]
+    trajectory_goal.trajectory.header.stamp = rospy.Time(0.0)
+    trajectory_goal.trajectory.header.frame_id = 'base_link'
 
-    def main(self):
-        hm.HelloNode.main(self, 'multipoint_command', 'multipoint_command', wait_for_first_pointcloud=False)
-        rospy.loginfo('issuing multipoint command...')
-        self.issue_multipoint_command()
-        time.sleep(2)
+    self.trajectory_client.send_goal(trajectory_goal)
+    rospy.loginfo('Sent stow goal = {0}'.format(trajectory_goal))
+    self.trajectory_client.wait_for_result()
+
+  def main(self):
+    """
+    Function that initiates the multipoint_command function.
+    :param self: The self reference.
+    """
+    hm.HelloNode.main(self, 'multipoint_command', 'multipoint_command', wait_for_first_pointcloud=False)
+    rospy.loginfo('issuing multipoint command...')
+    self.issue_multipoint_command()
+    time.sleep(2)
 
 
 if __name__ == '__main__':
-    try:
-        node = MultiPointCommand()
-        node.main()
-    except KeyboardInterrupt:
-        rospy.loginfo('interrupt received, so shutting down')
+  try:
+    node = MultiPointCommand()
+    node.main()
+  except KeyboardInterrupt:
+    rospy.loginfo('interrupt received, so shutting down')
 
 ```