[Python-Dev] Reintroduce or drop completly hex, bz2, rot13, ... codecs

[Nick Coghlan]

On 09/06/10 22:18, Victor Stinner wrote:
> Le mercredi 09 juin 2010 10:41:29, M.-A. Lemburg a écrit :
>> No, .transform() and .untransform() will be interface to same-type
>> codecs, i.e. ones that convert bytes to bytes or str to str. As with
>> .encode()/.decode() these helper methods also implement type safety
>> of the return type.
>
> What about buffer compatible objects like array.array(), memoryview(), etc.?
> Should we use codecs.encode() / codecs.decode() for these types?

There are probably enough subtleties that this is all worth specifying 
in a PEP:

- which codecs from 2.x are to be restored
- the domain each codec operates in (binary data or text)*
- review behaviour of codecs.encode and codecs.decode
- behaviour of the new str, bytes and bytearray (un)transform methods
- whether to add helper methods for reverse codecs (like base64)

The PEP would also serve as a reference back to both this discussion and 
the previous one (which was long enough ago that I've forgotten most of it).

*Some are obvious, such as rot13 being text only, and bz2 being binary 
data only, but others are less clear. hex could be either str->str or 
bytes->bytes, since ''.join(map(chr, seq)) and b''.join(map(ord, seq)) 
allow each of them to be implemented trivially in terms of the other. As 
Antoine pointed out, base64 is really a reverse codec (encode from 
bytes->str, decode from str->bytes), so it still wouldn't be covered by 
the new transformation helper methods.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
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