Comment by billmania for From: https://docs.ros.org/api/catkin/html/...Standard ROS practice is to place Python modules under the src/your_package subdirectory, making the top-level module name the same as your package. Python requires that directory to have an __init__.py file, too.Your python library sources are in nodes/ros_moos ; you should move them to src/ros_moos

A few paragraphs earlier in that same document one can find "Standard ROS practice is to place all executable Python programs in a package subdirectory named nodes/ or scripts/." In my project, nodes/ros_moos/auv_status.py is a Python executable program used as a ROS node by roslaunch. Does it belong under nodes or src? nodes/ros_moos/uuv_moos.py is only a Python module and not a ROS node. It's imported by auv_status.py. Must it and its ilk be moved to src/ros_moos and an __init__.py added to src/ros_moos? The following still doesn't make moos_ros.py and uuv_moos.py import-able. ├── nodes │   ├── ros_moos │   │   ├── auv_control.py │   │   ├── auv_status.py │   │   ├── __init__.py │   │   └── moos_test.py │   └── tests ├── package.xml ├── params │   └── auv_params.yaml ├── README.md ├── requirements.txt ├── setup.py └── src └── ros_moos ├── __init__.py ├── moos_ros.py └── uuv_moos.py