Thanks for your comment.
1) I did some research and as result tweaked the set example. Thanks for the remark though.
2) Using While 1 is not something significant as already stated. But at least have an advantage over While True.
3) I also tested F-string in linking many strings and the difference was not significant compared to + and join(). Considering that and the fact that f-string is more Pythonic, I think it's a good option.