[Python-3000] Support for PEP 3131

[Ka-Ping Yee]

On Fri, 25 May 2007, Blake Winton wrote:
> Jim Jewett wrote:
>  > Arbitrary Unicode identifier opens up the possibility of code that
>  > *looks* like ASCII, but isn't -- so I don't even realize that I missed
>  > something.
>
> You already have that problem.  Right now.  And you've had it for at
> least a year (assuming you installed 2.4.3 when it came out).
>
> All screenshots taken on Python 2.4.3, Mac OSX 10.4 Intel.
>
> http://bwinton.latte.ca/temp/Python/File.png
> http://bwinton.latte.ca/temp/Python/Run.png
> http://bwinton.latte.ca/temp/Python/foo.py

Yes -- you have demonstrated exactly why the default encoding for
Python files should be 7-bit ASCII, and why a coding declaration should
be required to switch to other encodings, to let the reader know that
the file might not contain what it appears to contain.

Your file, like tricky.py, relies on the invisible enabling of UTF-8
by a UTF-8-encoded BOM at the beginning of the file.

Switching to UTF-8 invisibly (or by default) is dangerous; enabling
non-ASCII identifiers by default augments this problem to a whole
new level.  Neither should be the default.


-- ?!ng