TheJust for completeness as nobody else has mentioned it. The third parameter to an array slice is a step. So So reversing a string is as simple as:
some_string[::-1]
Or selecting alternate characters would be:
"H-e-l-l-o- -W-o-r-l-d"[::2] # Outputsoutputs "Hello World"
The ability to step forwards and backwards through the string maintains consistency with being able to array slice from the start or end.