title: how to import ROS .msg files in python which are not part of the usual .msg path?
body: <p>I am using <a href="https://github.com/appie-17/tello_driver" rel="nofollow noreferrer">this</a> driver here for ROS. The driver is inside my ROS catkin workspace (catkin_ws).
  Inside this workspace I have another package from where I want to <code>import TelloStatus</code> which is located in <code>tello_driver/msg/TelloStatus.msg</code></p>
  <p>Usually messages (msg) in ROS are imported this way:</p>
  <p>Examples:</p>
  <pre><code>from geometry_msgs.msg import Twist
  from std_msgs.msg import Empty
  from sensor_msgs.msg import Imu
  </code></pre>
  <p>I think that these files are located at the following path on the system:</p>
  <pre><code>opt/ros/noetic/share
  </code></pre>
  <p>So my question is how can I import <code>TelloStatus</code> which is not part of this path but part of the <code>tello_driver</code> package?</p>
  <p>I tried to import it the following way:</p>
  <pre><code>import sys
  sys.path.append('/home/usr/catkin_ws/src/tello_driver/msg/TelloStatus.msg')
  import TelloStatus
  </code></pre>
  <p>but then I get this error message:</p>
  <pre><code>import TelloStatus
  ModuleNotFoundError: No module named 'TelloStatus'
  </code></pre>
  <p>Thanks for help in advance!</p>