Q:

where I should print my results

I'm talking about good practies, expetially in C/C++ or Python field ( but my question is not based on a specific programming language).
When I want to print a result, where I should put my printf or cout or print?
If this result is computed by a function and then it is returned to main, I should print it in the main or not?
Should the main be free from console output?

A:

If this result is computed by a function and then it is returned to
  main, I should print it in the main or not?

Yes, print it on main. In your case I think you can just do the print of the function like: print(functionWithReturnType());
You can also define a variable equal to the function type, and define it equal to the value that the function return, in case you want to use that value more than once.

Should the main be free from console output?

No. You should allways put the console output in main.

