def enforce_hex(addr):
    if ((type(addr) == int) and (addr < 256)):
        return hex(addr).lstrip('0x')
    elif (type(addr) == str):
        return addr.lstrip('0x')
    else:
        raise ValueError('addr must be hex string or int < 256')
def enforce_hex(addr):
    if ((type(addr) == int) and (addr < 256)):
        return hex(addr).lstrip('0x')
    elif (type(addr) == str):
        return addr.lstrip('0x')
    else:
        raise ValueError('addr must be hex string or int < 256')