Thanks for this nice article. As the tasks you gave in the examples are not codes that make IO operations, they wouldn't work in parallel. Because they do completely CPU intensive jobs and, in fact, they still work synchronously although print the result at once. It would be possible that they could have been working in parallel only if they made some IO operations like reading files or making some network calls.

Could you please give us more technical details and correct me if I'm wrong?

Thanks.