[Python-Dev] i18n identifiers (was: Divorcing str and unicode (no more implicit conversions).

["Martin v. Löwis"]

Steve Holden wrote:
> Therefore, if such steps are really going to be considered, I would 
> really like to see them introduced in such a way that no breakage occurs 
> for existing users, even the parochial ones who feel they (and their 
> programs) don't need to understand anything but ASCII.

It is straight-forward to make this feature completely backwards
compatible. Syntactically, it is a pure extension: existing code
will continue to work unmodified, and will continue to have the
same meaning. With the feature, you will be able to write code
that previously produced SyntaxErrors.

Semantically, the only potential incompatibility is that you
might find Unicode strings in __dict__. If purely-ASCII identifiers
are going to be represented by byte strings (as they are now),
no change in meaning for existing code is anticipated.

So it is not necessary to make the feature conditional to preserve
compatibility.

Regards,
Martin