def _get_nibbles(char):
 try:
  (x, y) = hex(ord(char))[2:]
 except:
  x = '0'
  y = hex(ord(char))[2:]
 return (x, y)

def _get_nibbles ( char ) : try : ( x , y ) = hex ( ord ( char ) ) [ 2 : ] except : x = '0' y = hex ( ord ( char ) ) [ 2 : ] return ( x , y )
a helper function for the decoding functions :return: the first ans second nibble of the ascii value of the char .