Python - Converting character string to HEXA string

ord(c): Given a string of length one, return an integer representing the Unicode code point of the character when the argument is a unicode object, or the value of the byte when the argument is an 8-bit string.

>>> ord("a")
97
>>> ord("\t")
9

hex(n): Convert an integer number to a hexadecimal string

>>> hex (97)
'0x61'
>>> hex (9)
'0x9'

We do not need first to characters in the hex output.

>>> hex (97)[2:]
'61'
>>> hex (9)[2:]
'9'

zfill(witdh): Return the numeric string left filled with zeros in a string of length width.

>>> hex (97)[2:].zfill (3)
'061'
>>> hex (9)[2:].zfill (2)
'09'

Put of together,

>>> s="\x08\t\x07khr\x00"
>>> "".join ([hex (ord(c))[2:].zfill(2) for c in s])
'0809076b687200'

Reference:
href=http://docs.python.org/library/functions.html