DR_init Import Issue

If a dr_init error occurs even after a successful build, please refer to the following information. This document describes a common error related to the DR_init module in the Doosan ROS 2 environment, including the root cause and its resolution.

1. Error Case

When running a Python script such as dance_m1013.py, the following error occurs:

$:~/ros2_ws/src/doosan-robot2/dsr_example2/dsr_example/dsr_example/demo$ python3 dance_m1013.py
ModuleNotFoundError: No module named 'DR_init'

This indicates that Python is unable to locate the DR_init module.

2. Root Cause Analysis

The error is caused by the PYTHONPATH not including the installation path of the DR_init.py file. By default, ROS 2 installs this module inside the install/dsr_common2/lib/dsr_common2/imp/ directory, which is not automatically included in the Python import path.

3. Solution

To resolve the issue, explicitly set the PYTHONPATH environment variable to include the location of DR_init.py.

Step-by-step instructions:

# Step 1: Locate the module
find ~/ros2_ws -name "DR_init.py"

# Step 2: Set the PYTHONPATH
export PYTHONPATH=~/ros2_ws/install/dsr_common2/lib/dsr_common2/imp

# Step 3: Source the changes
source ~/.bashrc

# (Optional) Check if PYTHONPATH is set correctly
echo $PYTHONPATH

# (Optional) Reset PYTHONPATH if needed
unset PYTHONPATH

Note: You can also add the export PYTHONPATH=… line to your ~/.bashrc or ~/.zshrc for persistent usage across terminals.

This should ensure that the Python runtime correctly resolves the DR_init module and prevents import errors.