How can I make this more efficient? And Without using split() and join()

Question

https://code.sololearn.com/cCIL3y9zJnbX/?ref=app

Answer 1

You can do it without split and join, but I bet it will be less efficient

Answer 2

Input: some text in my book
Output: emos txet ni ym koob

Answer 3

If you want to reverse order of letters while keeping words order, than I can't think of doing it without seperating the words at some point. Sorry!