[Python-Dev] Reintroduce or drop completly hex, bz2, rot13, ... codecs (original) (raw)

M.-A. Lemburg mal at egenix.com
Wed Jun 9 13:53:08 CEST 2010

Antoine Pitrou wrote:

On Wed, 09 Jun 2010 10:41:29 +0200 "M.-A. Lemburg" <mal at egenix.com> wrote:

The above example will read: >>> b'abc'.transform("hex") b'616263' >>> b'616263'.untranform("hex") b'abc' This doesn't look right to me. Hex-encoded "data" is really text (it's a textual representation of binary, and isn't often used as an opaque binary transport encoding).

Then we'd need new .encode() and .decode() methods, so that we could write:

 >>> b'abc'.encode("hex")
 '616263'
 >>> '616263'.decode("hex")
 b'abc'

The reason is that we don't have helper methods for the directions encoding: bytes->str and decoding: str->bytes.

We do in Python2, so perhaps adding those back as well would be a possibility, but I don't want to strain all this too much.

It's always possible to use:

codecs.encode(b'abc') and codecs.decode('616263')

instead.

Of course, this is not necessarily so for all codecs. For base64-encoded data, for example, it is debatable whether you want it as ASCII bytes or unicode text.

Since there are multiple ways of choosing types, I would like to use the ones that Python2 already chose, if possible.

The only one I'm not sure about is 'rot13': this is an encoding that is only defined for text and works by creating mangled text, so str->str appears to be more correct than str->bytes (which we have in Python2).

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