colcon build

• build every packages in src

colcon build —packages-select my_py_pkg

colcon-argcomplete.bash should be added to make auto completion.

colcon build —packages-select my_py_pkg —symlink-install

• without re-building, it is simultaneously updated.
• in src, the node_name.py should be executable (chmod +x node_name.py )
• it is good for developing and debuging.
• It is working only for python. not cpp.