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

Tue Feb 14 01:49:55 CET 2006

On Feb 13, 2006, at 7:09 PM, Guido van Rossum wrote:
> On 2/13/06, Michael Foord <fuzzyman at voidspace.org.uk> wrote:
>> Sorry - I meant for the unicode to bytes case. A default encoding 
>> that
>> behaves differently to the current to implicit encodes/decodes 
>> would be
>> confusing IMHO.
>> And I am in agreement with you there (I think only Phillip argued 
> otherwise).
>>> I agree that string to bytes shouldn't change the value of the bytes.
>> It's a deal then.
>> Can the owner of PEP 332 update the PEP to record these decisions?

So, in python2.X, you have:
- bytes("\x80"), you get a bytestring with a single byte of value 
0x80 (when no encoding is specified, and the object is a str, it 
doesn't try to encode it at all).
- bytes("\x80", encoding="latin-1"), you get an error, because 
encoding "\x80" into latin-1 implicitly decodes it into a unicode 
object first, via the system-wide default: ascii.
- bytes(u"\x80"), you get an error, because the default encoding for 
a unicode string is ascii.
- bytes(u"\x80", encoding="latin-1"), you get a bytestring with a 
single byte of value 0x80.
In py3k, when the str object is eliminated, then what do you have? 
Perhaps
- bytes("\x80"), you get an error, encoding is required. There is no 
such thing as "default encoding" anymore, as there's no str object.
- bytes("\x80", encoding="latin-1"), you get a bytestring with a 
single byte of value 0x80.
James