Greg Ewing writes:
Stephen J. Turnbull wrote:
But even as a separate type, 'ascii' still can't mix with bytes safely,
Yes, it can, because it's also bytes. :-)
To the extent that's safe, you may as well just use str and force encoding with the ascii codec and strict errors (as I suggested earlier). AFAICS, the argument that the visual signal of the special literal syntax helps is bogus. It doesn't help with variables; variables aren't typed in Python. It's still just as possible to type a'äëïöü', although it might make the mistake a little more visible. And in most cases, the use case for this feature will be very stylized, with a very small vocabulary of ASCII puns, written as literals at the point of combination with a bytes object. Anything else I can think of should be handled as text, via conversion to str. I just don't see a use case for an 'ascii' type, vs. coercing str to bytes and raising an error if the str is not all-ASCII.
If you're using the special ascii type at all, rather than an ordinary str, it's precisely because you want to mix it with bytes. Making that part hard would defeat the purpose,
Indeed. Most alleged use cases for "mixing" *should* be made hard to do by operating on bytes directly. Cf. the mixed-encoding log file example.