We all recognize that ASCII is very much limited and that the real way to work with strings is Unicode.  However, here our hands are tied by our development process: shlex in 2.x does not support Unicode, adding that support would be a new feature, and 2.7 is closed to new features.  If shlex was supposed to support Unicode, then this would be a bug that could be fixed in 2.7, but it’s not.  All we can do is improve the 2.7 doc to show how to work around that (splitting on bytes and then decoding each chunk, for example).