def crc32(seq):
 try:
  return _crc32(_as_bytes(str(seq)))
 except AttributeError:
  return _crc32(_as_bytes(seq))

def crc32 ( seq ) : try : return _crc32 ( _as_bytes ( str ( seq ) ) ) except AttributeError : return _crc32 ( _as_bytes ( seq ) )
return a crc32 checksum of a file .