ROS BASICS IN 5 DAYS
2 - Ros basic
Example 1.6
The results show as in the picture.
How can I fix it?
Hi @6170434021,
check you launch file. XML does not allow whitespace to appear before the XML declaration (the <?xml .... ?> part). Remove this before parsing.
OK, Thank a lot, It works to me
but… I have a new problem.
I came back to try typing “roslaunch my_package my_package_launch_file.launch” again.
It shown "ROS_MASTER_URI=http://master:11311
“ERROR: cannot launch node of type [my_package/simple.py]:
can’t locate node [simple.py] in package [my_package]”
No processes to monitor
shutting down processing monitor…
… shutting down processing monitor complete"
And I try typing “ls -la” and add permissions.
But it still shows “ERROR: cannot launch node of type [my_package/simple.py]: can’t locate node [simple.py] in package [my_package]”
I don’t know what to do… 
thank you for helping me sir.
Is it possible to keep the simple.py file in the wrong place?
try chmod +x for the file
Just humor me and try it with ‘+x’
1 Like
I’m so sorry.
It’s X “X is letter not the numbers shown in the preview”
Did you build your package and source the setup.bash?