>String slicing with numbered indices is used all the time.

Ok, so it (EDIT FOR YOUR BENEFIT: I'm talking about slicing strings with rune indices here, not slicing in general. Array slicing is a useful language feature, and, uh, it's not unique to Python or anything) is not just a language wart, but a fertile source of pointless inefficiency in everyday Python code, glad to know.

>This might explain why my comments seem like heresy to you.

You aren't challenging my beliefs or anything, I'm just trying to make you see that you don't understand how UTF-8 string operations work very well. If you did, you'd understand that Python is doing the exact same thing as Go here, but in a less efficient manner.