def crc64(s):
 crcl = 0
 crch = 0
 for c in s:
  shr = ((crch & 255) << 24)
  temp1h = (crch >> 8)
  temp1l = ((crcl >> 8) | shr)
  idx = ((crcl ^ ord(c)) & 255)
  crch = (temp1h ^ _table_h[idx])
  crcl = temp1l
 return ('CRC-%08X%08X' % (crch, crcl))

def crc64 ( s ) : crcl = 0 crch = 0 for c in s : shr = ( ( crch & 255 ) << 24 ) temp1h = ( crch >> 8 ) temp1l = ( ( crcl >> 8 ) | shr ) idx = ( ( crcl ^ ord ( c ) ) & 255 ) crch = ( temp1h ^ _table_h [ idx ] ) crcl = temp1l return ( 'CRC-%08X%08X' % ( crch , crcl ) )
returns the crc64 checksum for a sequence .