[Python-Dev] PEP 332 revival in coordination with pep 349? [ Was:Re: release plan for 2.5 ?]

[Greg Ewing]

Guido van Rossum wrote:

> The only remaining question is what if anything to do with an
> encoding argment when the first argument is of type str...)

 From what you said earlier about str in 2.x being
interpretable as a unicode string which contains
only ascii, it seems to me that if you say

   bytes(s, encoding)

where s is a str, then by the presence of the encoding
argument you're saying that you want s to be treated as
unicode and encoded using the specified encoding.
So the result should be the same as

   bytes(u, encoding)

where u is a unicode string containing the same code
points as s. This implies that it should be an error
if s contains non-ascii characters.

This interpretation would satisfy the requirement for
a single call signature covering both unicode and
str-used-as-ascii-characters, while providing a
different call signature (without encoding) for
str-used-as-bytes.

-- 
Greg Ewing, Computer Science Dept, +--------------------------------------+
University of Canterbury,	   | Carpe post meridiam!          	  |
Christchurch, New Zealand	   | (I'm not a morning person.)          |
greg.ewing at canterbury.ac.nz	   +--------------------------------------+