The "kind" field is one of [uninitialized, Latin-1, UCS-2, UCS-4]. I'm not sure how it would pick UTF-8. (In memory usage, the Python way is strictly worse: a

The "kind" field is one of [uninitialized, Latin-1, UCS-2, UCS-4]. I'm not sure how it would pick UTF-8. (In memory usage, the Python way is strictly worse: adding one 4-byte character to an ASCII string forces the entire string to be upgraded to UCS-4. The advantage of the Python way is O(1) access to codepoints, but that's an operation that rarely comes up in practice, when dealing with Unicode strings.) I'm not sure how that would be compatible with Python, either. Either you're giving up string[index], or you're causing this one subscript operation to take O(n) time, or you need a new index type just for strings (which is what Swift does). None of these seem very 'Pythonic'. EDIT: Apparently recent versions of pypy solve this by computing their own index into your string, which seems like it would be terrible for memory usage, but I look forward to their blog post about it.