Alright, but don't leave us hanging: what does Python3 use for (2) that you say I was badly off on? (Or, in actuality, never thought about or meant to make claims about.) Now we still can't make good choices for performance!

https://stackoverflow.com/questions/1838170/what-is-internal... says Python3.3 picks either a one-, two-, or four-byte representation depending on which is the smallest one that can represent all characters in a string. If you have one character in the string that requires >2 bytes to represent, it'll make every character take 4 bytes in memory such that you can have O(1) lookups on arbitrary offsets. The more you know :)