NNTPHeader.py 文件源码

def __fmt_key(self, key):
        """Formats the hash key for more consistent hits; hence fetching the
        'Message-ID' key should still be fetched even if the user indexes
        with 'message-id'.
        """
        def _fmt(_k):
            return _k.group(1) + _k.group(2).upper()

        if not isinstance(key, basestring):
            # Handle invalid key entries types
            key = str(key)

        key = re.sub(
            # Flip -id to ID (short for Identifier)
            # Flip -crc to CRC (short for Cyclic Redundancy Check)
            r'([_-])((id|crc)([^a-z0-9]|$))',
            _fmt,
            re.sub(r'(^|\s|[_-])(\S)', _fmt, key.strip().lower()),
            flags=re.IGNORECASE,
        )
        if key in VALID_HEADER_ENTRIES or key.startswith(UNKNOWN_PREFIX):
            return key
        return UNKNOWN_PREFIX + key