hexstring to string?

[maximilianscherr]

i made a function to convert a hex string containing character to a 
normal string.

it looks like this:

class ConversionHandler:
    def ConvertHexToStr(self, hex):
        letter = 0
        str = ''
        while len(str) < len(hex) / 2:
            nextletter = letter + 2
            str = str + chr(int(hex[letter:nextletter], 16))
            letter = nextletter

        return str

hex looks like: 414243

but why does it not work?