python - How can I format an integer to a two digit hex?

Question

Does anyone know how to get a chr to hex conversion where the output is always two digits?

for example, if my conversion yields 0x1, I need to convert that to 0x01, since I am concatenating a long hex string.

The code that I am using is:

hexStr += hex(ord(byteStr[i]))[2:]

Answer 1

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().