def nodata(status_code):
    """Translate NODATA status codes from GnuPG to messages."""
    lookup = {
        '1': 'No armored data.',
        '2': 'Expected a packet but did not find one.',
        '3': 'Invalid packet found, this may indicate a non OpenPGP message.',
        '4': 'Signature expected but not found.' }
    for key, value in lookup.items():
        if str(status_code) == key:
            return value