Python, separate file handling

[Dirk.nl]

Cyrille thanks for your answer !!
I got confused about the <New Program> selection in <More>.
To me a new program is a really new program, you can select the newly created programs, indicated by a check mark. Then I thought; if I go to Num only this indicated program will be imported and run. Turns out everything is imported and run !
If I want to learn Python step by step with small programs, I will have to delete the previous one each time or copy the Python app a lot.
How are they going to do this in the classroom anytime soon (with small programs), without having to deal with HPPL?

Regards, Dirk