Create a valid mac-address from an string

snmp_calls.py

def create_valid_mac_address(mac_address):
    mac_address = mac_address.replace("-", "")
    if len(mac_address) != 12:
        raise InvalidMacAddressStringException("The String of the MAC-Address does not contain enough characters")
    if not all(c in string.hexdigits for c in mac_address):
        wrong_chars = ""
        for c in mac_address:
            if c not in string.hexdigits:
                wrong_chars += "#%s#" % c
            else:
                wrong_chars += c

        raise InvalidMacAddressStringException("The String contains characters, that are not hexadecimal: %s" % wrong_chars)
    else:
        mac_address = '-'.join(a+b for a,b in zip(mac_address[::2], mac_address[1::2]))
        mac_address = mac_address.upper()

        return mac_address