Problem executing roslaunch

I am applying the example of basic ros in 5 days on my pc and the following error occurs to me, could you please help me on how I can solve it, thanks
ERROR: cannot launch node of type [simple_pkg/simple.py]: can’t locate node [simple.py] in package [simple_pkg]

Hi Brayan,

This error means that you should make the simple.py file executable by running:

chmod +x simple.py

By the way, is it the ROS Perception course or the ROS Basics course? You have created this post on the Perception course.