How to use the 'hex' encoding in Python 3.2 or higher?

Yet another way using binascii.hexlify():

>>> import binascii
>>> binascii.hexlify(b'\x12\x34\x56\x78')
b'12345678'

You need to go via the codecs module and the hex_codec codec (or its hex alias if available^*):

codecs.encode(b'\x12', 'hex_codec')

_{* From the documentation: "Changed in version 3.4: Restoration of the aliases for the binary transforms".}