hex - python encode()

Question

Has hex codec been excluded from python 3.3? When I write the code

>>> s="Hallo"
>>> s.encode('hex')
Traceback (most recent call last):
  File "<pyshell#24>", line 1, in <module>
    s.encode('hex')
LookupError: unknown encoding: hex

What does that mean? I know about binascii.hexlify() but still .encode() method is nice! Any suggestion?

Answer 1

No, using encode() to hexlify isn't nice.

The way you use the hex codec worked in Python 2 because you can call encode() on 8-bit strings in Python 2, ie you can encode something that is already encoded. That doesn't make sense. encode() is for encoding Unicode strings into 8-bit strings, not for encoding 8-bit strings as 8-bit strings.

In Python 3 you can't call encode() on 8-bit strings anymore, so the hex codec became pointless and was removed.

Although you theoretically could have a hex codec and use it like this:

>>> import codecs
>>> hexlify = codecs.getencoder('hex')
>>> hexlify(b'Blaah')[0]
b'426c616168'

Using binascii is easier and nicer:

>>> import binascii
>>> binascii.hexlify(b'Blaah')
b'426c616168'