You are looking for the chr function.

You seem to be mixing decimal representations of integers and hex representations of integers, so it's not entirely clear what you need. Based on the description you gave, I think one of these snippets shows what you want.

>>> chr(0x65) == '\x65'
True


>>> hex(65)
'0x41'
>>> chr(65) == '\x41'
True

Note that this is quite different from a string containing an integer as hex. If that is what you want, use the hex builtin.

I think you might be mixing up numbers and their representations. 0x01234567 and 19088743 are the exact same thing. "0x01234567" and "19088743" are not (note the quotes).

To go from a string of hexadecimal characters, to an integer, use int(value, 16).

To go from an integer, to a string that represents that number in hex, use hex(value).

>>> a = 0x01234567
>>> b = 19088743
>>> a == b
True
>>> hex(b)
'0x1234567'
>>> int('01234567', 16)
19088743
>>>

You can use string formatting for this purpose:

>>> "0x{:02x}".format(13)
'0x0d'

>>> "0x{:02x}".format(131)
'0x83'

Edit: Your code suggests that you are trying to convert a string to a hexstring representation. There is a much easier way to do this (Python2.x):

>>> "abcd".encode("hex")
'61626364'

An alternative (that also works in Python 3.x) is the function binascii.hexlify().